Larry Cost Me $25 – Thermos Cooking

On another thread, Larry Ledwick mentioned cooking in a thermos bottle.

You can also help hot foods steep and heat soak by taking them off the flame and wrapping them in a cotton towel so they don’t quickly cool. Similar to the thermos cooking I mentioned a while back. Heat the food to 165-185 deg and pour in a small lunch box size stainless thermos and let it sit for 10 minutes or so instead of wasting fuel trying to bring it to a simmer or boil.

So today I was out buying a 250 gram butane canister for a camp stove, and there on the shelf was a nice 24 oz. Stanley brand wide mouth stainless steel thermos for $22.xx (plus 9%+ California sales tax). About $25 out the door. I couldn’t resist the opportunity to experiment…

At home, I’ve now done my first thermos cooking experiment. I brought a small pan of water to the boil, and put some 3 inch long pieces of tubeti (think long macaroni) in it. Brought it back to the boil, then poured it through a canning funnel into the thermos. Lid on, let it sit about 14 minutes.

Upon opening, the measured temperature was around 190-195 F. So about a 17 F drop in the pouring and standing steps. I poured “the works” into a sieve to drain, then put the noodles in a bowl. A bare noodle was properly cooked, but with a slightly soft surface. Not quite “gummy”, but not as smooth as noodles cooked at a boil. Good enough, though. With Alfredo sauce and some chopped bits of cooked ham added, it was quite nice. I just dumped the sauce, from a refrigerated jar, onto the noodles and let the residual heat from the noodles warm the sauce from refrigerated temperature to “nice”.


If something really needs to be boiled, this will not quite get there. A preheat of the thermos with boiling water may get close enough.

“Slow Cooker” recipes ought to work OK. Just get it to the simmer / boil point, pour in, and wait about 8 hours. (This particular thermos claims a 15 hour hot temperature hold time)

It is a little hard to clean the thermos. I used a “bottle brush”. This isn’t going to be a main form of cooking for me just because I’d rather just run pots through the dish washing machine. Hand washing a thermos with a bottle brush to get out beef stew is not my idea of fun. (If anyone knows of a dish washer safe thermos, put up a note!)

It would work well as a fuel saving method “on the trail”, but it would take a lot of fuel savings to make up the weight. In a “survival” at home situation, it would be a good way to extend fuel, but at the cost of wash water. Cooking watery things would clean easier than those with a gravy.

It might work best to use an immersion heater (those small cup heater coils, if they are still made) to raise the contents to the boil inside the thermos for best cooking. In a pinch, what it does with the heat-then-pour is good enough for a lot of foods. Cut food into small pieces so you don’t have a big cold lump in the middle of a chicken leg causing equilibrium temperature to end up something like 150 F and growing cultures of “chicken germs”.

I’m now going to set about trying several different recipes to see what works. If anyone has known working recipes, post ’em! Oh Joy, a new kind of cooking to explore! ;-) Worth far more than $25 just in entertainment value… There are several web pages that claim to be recipes but that’s going to take a while to work through:

A “Thermal Cooker”, like a pot sized thermos:

From Amazon:

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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70 Responses to Larry Cost Me $25 – Thermos Cooking

  1. Larry Ledwick says:

    Sorry about that ;)

    I got to thinking about the issue of pre-heating (like your Mum and my Mom did with tea I suspect).

    Bring just the water to a boil in a sauce pan, pour off some of it into the the thermos so it can pre-heat, then after a couple minutes of heat soak pour the water back into the sauce pan, and add your ingredients for dinner, then once up to boiling pour the whole lot back into the pre-warmed thermos.

    The way I cook rice on the stove is add x amount of rice to the pan, add just a tad more than 2*x water to the rice, and bring to a boil. Once at a boil lower the heat to the lowest possible setting and let it soak until all the water is absorbed (typically about 20 minutes or so [I have not measured it I monitor it by visual checking])

    I suspect the same method could be used for cooking standard rice in a thermos with a slightly longer time to steep in the thermos.

    I will be back in about 30 minutes and report on an experiment.

    – – – – – – – –

    In my situation I have an all electric kitchen (which sucks I much prefer gas to cook) but my hot water heater is natural gas. In the case of only an electrical outage, I could pre-heat the thermos with hot water from the tap, as described above then decant the heat soak water into a pan to heat on an auxiliary cook stove like the Coleman camping stove. The toss the works into the thermos to heat steep at temp.

    In that special case I would do about 80% of my cooking process with the hot tap water.

  2. E.M.Smith says:


    No worries, I expect I might cost you $56 or so for a Thermal Cooker ;-)

    I find it fascinating that the ersatz Thermos cooking seems to have sprouted a new cooking device, the ThermAL Cooker… I know I’m eventually going to buy one (well, almost know … a couple more experiments in the thermos first… to prove i like the results. I have some red potatoes & carrots with a chicken bouillon cube soaking in it at the moment – Hoping for a “savory vegetable” side)

    Provided I get at all “into it” with the thermos, I’m ordering the thermAL cooker… The idea of “heat and walk away” for hours has much appeal. When “hotel camping” I typically use a very small (one Cornish Game Hen sized) slow cooker; but I always worry about the maid seeing it and unplugging it or management being a pill about it. Now, instead, I could preheat on my one burner electric 1500 W element, dump in the Thermal Cooker pot, and walk away. Nothing plugged in, nothing to see, nothing to worry about. Back after work (or now perhaps, outing) meal is waiting…

  3. Larry Ledwick says:

    Okay time for the experiment report.

    For myself I have found that 3 oz of dry rice cooks up to a nice single serving size plate of rice. I measure it out in a 3 oz shot glass sized plastic cup (like used for pill cups in the hospital).

    I am using a 17oz Kuuk stainless lunch thermos.
    Kuuk stainless steel lunch thermos

    Keep in mind I am at almost 6000 ft altitude so my boiling temp will be a bit lower than folks at sea level at about 200 deg F.

    I took a 3 oz cup of dry rice.
    Put 8 oz of tepid tap water in a sauce pan and brought it to a boil.
    Poured off about 3/4 of it into the thermos and let it set for about 2-3 minutes with occasional shaking so the whole interior of the thermos would have direct contact with the hot water.

    Poured the water out of the thermos and back into the sauce pan and added the rice, and covered the pan. Brought the rice and water mix to a full boil and then poured the water rice mix into the thermos bottle and capped it.

    I periodically checked it by shaking. At first there was the clear sound of sloshing water but starting around 25-30 minutes it sounded more like slush.

    At 35 minutes I opened it and pulled out a few grains of rice. They were partially cooked (edible at this point) with the core of the rice kernal slightly crunchy and starchy tasting the appearance was not quite fully cooked the rice kernals were still not the normal plump fluffy looks stove cooked rice has.

    At 45 minutes temp of rice is 167 deg F, rice looks fully cooked and fluffy, but is still a bit wet and still slightly starchy in the center.

    At 55 minutes temp of rice is 158 deg F
    Still slightly starchy in the center but I have declared this good enough and decided to eat.

  4. Larry Ledwick says:

    With a little bit of warmed up Chicken Chow Mein sauce on it from the fridge this is perfectly edible you don’t notice the rice is not quite prefect. If you were really hungry you wouldn’t care anyway even if you did notice.

    Next time I will use about 7 ounce of water.
    Warm the thermos for a couple minutes longer and hold the rice at a boil for 2-3 min before I put it in the thermos.

    Let is steep for 60 – 65 minutes.

  5. Larry Ledwick says:

    I will have to look into the thermal cookers.

    First I want to experiment with super insulating one of these little lunch thermoses, and possibly pre-heating the outside shell too when I pre-heat the interior. (pour 2/3 of the water inside and set the thermos in the remaining third of the water while it pre-heats to warm the outer shell)

    A towel wrap or a custom built urethane foam super insulated outer shell so it holds heat a bit better

  6. E.M.Smith says:

    As I’m very fond of rice, especially in that my gross survival calories are about 1/4 rice, anything that gives a lower fuel burn in that situation is very desirable.

    I’ve got an electric rice cooker that can run from the generator, but that’s a lot of fuel and conversions. (Not to mention noise).

    I have cooked rice on the stove, but not burning it takes tending.

    I have a microwave rice cooker (strange plastic bowl) that works OK with less electricity, but isn’t the best rice and requires the generator in an Aw Shit situation.

    So I’ve basically figured I’d just suck it up on fuel and cook it in a pot. (Thus the large amount of Sterno that holds a nice simmer without my tending it… sure it’s slow, call it a feature and match it to a 20 minute rice simmer in a pot…)

    However, just doing one “5 minute boil” then dump in the thermos would be wonderful saving of fuel and tending in an Aw Shit situation. And, like you, I’m OK with slightly starchy and even minor crunch center rice…

    I think a “red beans and rice” effort is in my future ;-) Yes, I have an extraordinary fondness of “Red Beans & Rice” (or Caribbean black beans and rice…)

    Oh, and anyone playing with this remember that:


    Every year or two somebody gets a run to the medic trying to make their favorite chili in a slow cooker and use re-hydrated kidney beans (soaked). One must do the “fast soak” where you boil them a few minutes then let them sit an hour or two. Lectins and all that. Oddly, other beans don’t have that problem.

    Canned kidney beans are OK as they have already had a high temp cook.

    Well, FWIW, your Rice Research is worth more than the $25 I’m out for my thermos, so “we’re even” ;-)

    Oh, and I always just use one unit rice to two units water. Same thing for other grains. Seems nearly universal.

  7. jim2 says:

    So, is there a portable, camping/hiking pressure cooker? Bet there would be a market at 6,000-14,000 feet :)

  8. E.M.Smith says:

    After a couple of hours, some spuds ( about inch square chunks) and carrots (1/2 inch chunks) boiled with a bouillon cube and in the thermos for a couple of hours (about 2.5 ) are rather nice.

    They could sit longer and still be fine. Measures about 175 F to 180 F. I gave them about a 2 minute boil before pouring in. At the 175 F point, they ought not get too soft or over cooked even with hours more standing.

    I think in the future I need to take a starting temp after the pour and a final temp on opening. As it stands, I don’t know how much is thermos heat loss and how much is evaporation in the pour.

    My guess is that with meat cut into small enough pieces to be heated through in the first boil (call it 1/2 inch section or less) you could easily make meat stews safely this way. ( I tested just with potatoes and carrots first to characterize things on the cheap… ) Some future day will involve using chicken bits or lamb slices.

    I think I’ll proceed to decanting the vegetables in the next hour, and then try some grain thing… or maybe lentils. Normally lentils take a 20 minute boil. I’d bet a 2 to 5 minute boil then sit would work…

  9. Larry Ledwick says:

    For cooking rice on the stove with minimum tending I use this method.

    Figure out how much dry rice you will use (3 oz of dry rice makes a large plate of cooked rice)
    Wash it and then add 2x the water plus about 1 oz (ie 12-13 oz water for 6 oz of dry rice.

    Bring to a good boil where it tries to boil over then turn the stove down to literally its lowest heat setting on that burner.

    If possible cook the rice in a pan with a glass lid.

    The rice is cooked with you stop seeing steam coming out from the edge of the lid, or condensate dripping off the lid back into the rice and no bubbles of steam forming in the rice.

    Turn off the heat and let it rest for a couple minutes before serving.

    If you listen carefully just as the rice is about to boil dry, you will hear a faint crackly sound (sort of like rice crispies). If you hear that – Turn off the heat, put the pan on a hot pad, pop the lid and add a table spoon or so of water and let it rest for a couple minutes.

    Since I started using that method, I very very rarely burn a pan of rice when I let my self get distracted and fail to check.

  10. E.M.Smith says:


    Yes, there is. FWIW, I have one of these I regularly use for mashed potatoes:

    5 min “rocking” then sit to drop pressure (about another 5) then decant and run the mixer through it with some butter, dash of milk, salt, and white pepper shake over. YUM! Just right for 2 people with some leftovers. 2 adults and a kid or two would work with added side dishes.

    There are more “camp” style out there, but this is already pretty minimal. I absolutely love it.

    This gizmo isn’t a pressure cooker, but it’s in the same idea of a one pot meal with easy heating from variety sources:

    The GSI folks make a 2.8 L one for camping, but that’s a bit big IMHO.

    Then again, it likely depends on size of your tribe…

    There may be others, but frankly, I can’t see much use for smaller than the 1.5 L nor any way to make one simpler or lighter (other than using titanium… at a gazillion $$$)

  11. Terry Jackson says:

    Have done the same concept in the oven. Heat to 450 or so, inset roast or whatever, leave heat on for 5 to 15 minutes depending on size (bigger/thicker longer), turn off oven come back at end of day and warm for 20 minuted or so. This needs a well insulated and sealed oven.
    Back when we carried our lunch in a pail there were wide mouth thermos (thermi) for stew and such, easy to clean and worked well. Narrow mouth ones got an overnight soak once a week wit hot water and baking soda.

  12. E.M.Smith says:

    Looks like Hawkins has a 2 L stainless steel one (2.08 kg) that’s almost as small as the 1.5 L aluminum (1.28 kg). (They have a 2 L aluminum one [1.5 kg] as well, but no 1.5 L SS). The picture is strange but I think it’s just trying to be cute with a reflection of the bottom in the work surface.

    These folks have a good thread on motorcycle camping /cooking including bread in a pressure cooker:

    One guy has an interesting process of mixing bread dough in a baggy, kneading and rising in the baggy, then turning out into a pan to cook.

    Video of camp cooking with the 2.7 L size.

  13. E.M.Smith says:

    Well, I’m now enjoying a very nice bowl of rice with sugar and milk.

    Simmered for 5 minutes. Rinsed inside of thermos with hot water from the tap and let it sit a minute. Decanted and filled from the pot. Let sit about an hour (maybe almost 2… was watching TV).

    The rice is quite good. I used my usual 2:1 water:rice ratio, then reading about Jasmin rice found where it’s supposed to have less than my usual rice (bought this on a whim) at 1:1 or 1.25:1. So it’s a bit gummy, but it looks like that’s me not knowing Jasmin rice more than the cooker / process. I’ll try again another day with Calrose that does work well at 2:1 ratio.

    This is sort of like a risotto.

    I suspect a whole family of dishes could be made this way. Various vegetable / seafood things or perhaps even a rice pudding desert.

    I’d also guess the total fuel burn was about 1/2 or less.

    Reading about “pressure cooker rice” it says to cook for 3 minutes, then let pressure naturally fall for ten. (Where I found the Jasmine rice ratio at 1:1 and written by an Asian couple so it must be right ;-) The pressure cooker will take a bit longer to heat to 240 F at pressure, so I’d guess the two methods ought to be about the same total fuel burn. Guessing 2 minutes more to heat to fell pressure vs just simmer temperature.

    IF that’s the case, it looks like the small pressure cooker would be as efficient (but in a totally different way) as the slow cooking thermos approach. It might well vary by particular dish.

    The 1.5 L pressure cooker was originally bought in Florida at a Indian / Caribbean food store and was intended to be part of my “Road Kitchen” box. It works very well in that role cooking for one. I’d likely get the 2 L for use at home as the low end for 2 people. The 1.5 L works, but I have to fill it to the top for mashed potatoes for two of us if I want any extra / left overs. I usually get about one ‘sandwich box’ storage tub of extra out of it if filled to the limit of getting the lid in /on. If left an inch or two down for easy lid installation, and we just have “Meat and Mashed” (Bangers and mash) then it’s close run on the spuds… Though I’m a big guy who loves spuds so maybe it’s just me ;-)

  14. Graeme No.3 says:

    This is an old concept in Australia, used to be known as Hay Box cooking. The pot would be boiled in the morning and then (with lid on) put in a box surrounded by hay as insulation to cook over a number of hours. The cookers you illustrate are just an up-dated approach. There are a number of these sold in Australia and commonly used by those travelling esp. with a caravan. Heat the food in the inner pot in the morning, place inside the insulating holder and have a hot meal lunchtime or even evening. Sizes run up to 5 Litres and there are versions with double layer pans.
    I looked at them some years ago as an alternative to leaving the slow cooker going all day but felt the price unjustified.
    has some comments which may be of interest.
    claims its ben in use since medieval times.

  15. Larry Ledwick says:

    That is the first place I heard of this, as a method used by sheep herders. Dig a pit put the pot on the fire in the pit, then shovel some dirt on the coals put the pot back in and cover with grass and such. Hot meal when they came back to camp in the evening.

  16. E.M.Smith says:

    Don’t forget Hawaiian roast pig. Dig a pit. Make a fire. Wrap whole pig in banana leaves (several layers) Let fire go out. Lay pig on ashes / coals. Cover with dirt. Go to bed. Next day have a wedding (at lest in the one I went too…) then in the afternoon, dig up pig and party hardy…

    Then there’s the old British tradition of a large pot on an iron arm near the fire place. Put stuff in and let it slow cook all day long near the warmth of the fireplace. You could put it over the fire for fast, or let it sit on a warm hearth after the fire was out to very slow cook.

    Also, when I was about 8 we had a cook from Oklahoma in the restaurant. She made “chicken innards in gravy” with all the giblets we collected from making fried chicken. Several times I asked her how she cooked them (as I really loved them). She’d say “roll in seasoned flour, place in a large flat steam table pan, put them in the steam table and they are ready by lunchtime.” And I’d ask again as I’d not heard any of the words I knew of as a kind of cooking (fry, roast, bake, …). Only some 30 years or so later did it dawn on me that the steam table ran about 180 F to 190 F and it WAS a slow cooker. “place them in the steam table” was the cooking method.

    So people have been slow cooking for a very long time. And using available low grade heat in any form available.

    OH, and I was once told a way to cook squirrels was to wait for the fire to get low and toss it in. Burns all the fur and bugs off. Fire goes out, then it very slow cooks inside the skin for several hours from residual heat. After that you just peal back the (crispy) skin and pull the meat off. (Avoid opening the belly…) I would wager stone age folks were cooking that way… low and slow and residual heat.. Maybe even as the FIRST way of cooking.

    I’m pretty sure I remember directions to use a Dutch Oven (the kind with legs) in that way too. Few briquettes to get it going, then bury it in stuff… {he taps out a search…} Yup!:

    If you are in a place where you can do it, the very best way to cook meat is to bury it in the ground.

    [Fill oven with meat and vegetables and make a 2 foot round x 2 foot deep hole. Make coals in the bottom and next to it. Put some foil over your oven to keep dirt out. Down in the hole on the coals, top with the other coals.

    Cover the oven with the handle straight up and add enough moist dirt to completely cover the fire. If you can see any smoke, add more dirt. It will take about 6 hours for this to cook.

    I wonder if it started with wild fires and slow cooked critters in burrows…

  17. Larry Ledwick says:

    Your comments reminded me of another “expedient” cooking method. Catch and gut fish, coat fish with thick layer of mud ( I don’t recall mention of a leaf wrap). Toss the muddy fish in the fire and let cook. After an appropriate period of time, pull the fish out of the ashes and peal off the hard baked mud (skin/scales of fish is supposed to come off with the mud) and pull the fish meat off the bones.

  18. E.M.Smith says:

    IIRC, 4 inch thick Styrofoam has a very high R value and an 8 x 4 foot panel of it is dirt cheap. A box 2 foot on a side would take 24 sq ft. A panel is 32, so some left over for spares and kerf. I think you can get some insulation boards that are double face coated with reflective foil. An insulated put inside one of those ought to take forever to cool…

    The problem I’m seeing with Thermal Cookers is they don’t seem to come in “Small”. Due to the mass as cube surface area as square property, they work better with larger size. I just don’t need 4 or 6 liters of stew… I like a 2 L size for pots. Smallest I’ve found so far is 3 L.

    There’s probably an overlap with very large thermoses. But the Thermal Cookers have a nice easy to put in the dishwasher removable pot… I’m going to let it wait a bit while trying small recipes in the thermos (perhaps with added insulation so it cools more like a larger Thermal Cooker) then look for a 2.5 to 3 L size.

    Damn. I have a habit of doing a quick search when I assert something. Found a 1.5 L one on Amazon:
    Thermos brand.

    So looks like small ones do exist. $70 seems a bit steep for a big thermos, but it does have an inner pot too. Well, I’ll still be waiting a bit before buying one, but at least now I know my favorite size “for one or two” exists.

  19. E.M.Smith says:

    This looks like the gizmo for me. A “bento” box container. Two inner pots, one for the main meal one for rice, with a plastic inner lid to stop spills and increase insulation, and a 1.6 L size.

    Includes a folding spoon and claims a 12 hour keep warm time. Low cost at $27 (where the Thermos brand stuff is very pricey and one of their small flat ones has metal handle supports from the inner pot to outside for a BIG thermal leak path).

    OK, clearly the Asians / Japanese are ahead of the curve on this one. I feel a road trip to the Marina grocery store (big Asian grocer with large cookware section) is in order. Nothing like browsing the stuff on the shelf to see what features might matter and what the folks who buy a lot of this stuff like to stock.

  20. Larry Ledwick says:

    I use this stuff to improve the insulation on coolers when I go out to Bonneville. It is called Reach Barrier (not sure if that is a brand name or a functional term) but it is basically a polyethylene bubble pack like material with reflective aluminized Mylar facing on both sides. I get it at home depot. It significantly reduces heat loss due to radiant heat exchange and is tough and flexible.

    Reach Barrier radiant insulation blanket

    By the way best way to cut Styrofoam bead board or other foam insulation is to use a serrated bread knife, rather than a saw or plain knife. (zero loss due to saw kerf and greatly reduces all the statically charged bits of Styrofoam which get everywhere.

  21. jim2 says:

    The Snowline camping pressure cooker blurb claims it uses 1/4 less fuel than a conventional pot. That number would vary a good bit with altitude.

  22. pouncer says:

    Our host tells us “Upon opening, the measured temperature was around 190-195 F. So about a 17 F drop in the pouring and standing steps. …”

    Have you seen these soapstone cubes as used to cool whiskey?

    Instead of very slowly absorbing heat from a beverage, such stones can slowly release heat into a stew or pasta inside a thermos. While the very hottest, circa 200 degree, water coming off the boil during a pour into the pot loses a lot of heat to vapor, the solid rocks at the same temperature fall throughout the pour into the mix and new container while they STAY 200 or so degrees. So you cover the thermos and shake gently, every so often. Hot dense rocks at the bottom, INSIDE the pot, should warm a slow convective circulation of broth and solids of the still-cooking meal.

  23. E.M.Smith says:


    I have a set of them given to me as a Christmas gift. Only used in Scotch so far…. Never thought of heating with them (very small – about 2 cu in.) but in a small thermos…

    In a several hour slow cook, shaking would not be needed. Simple heat conduction would be more than enough (we’re talking 4 inches distance over hours).

    Interesting idea. I’m more likely to go with the ‘inner pots’ device (bento thing) as that would avoid the whole pouring through a funnel counter current air flow thing. Set simmering pot in insulated bucket and be done. Besides, wouldn’t want left over curry flavor getting into my Scotch ;-0

  24. E.M.Smith says:

    This is an interesting one. Stanley makes a “Thermal Crock” of 3 quarts size:

    Expensive at $62, but intended for the camping crowd (i.e. sturdy approach). Has an odd “hook” inside the lid to you can hang it on the edge of the pot (i.e. not puzzled trying to set it on dirty camp table). 3 quarts is a bit big for me, but sometimes would be about right for 2. Leave some head room it’s a nice 1/2 gallon of actual food. That would hold a decent stew, chili or curry. Claims a 12 hour keep warm time (so a 6 or 8 hour cook time ala slow cooker ought to be ‘easy’). Roughly a 9 inch right circular cylinder so minimal surface area. 8.7 inch x 9.4 inch.

    This is a different make 24 oz roughly right circular cylinder with a lid that looks to also have a stainless steel vacuum disk in it:

    Would be easier to empty / clean than the 24 oz thermos shape I have now. (It works well for liquids, but getting the rice out of the bottom needed a rubber spatula…)

    This one is 600 ml and anticipates cooling / condensation vacuum issues with opening a screw top.

    The inner lid has a push button to release any vacuum to make it easier to open.

    Then there’s this one that sort of looks ideal, but confusing pictures;

    It’s 58 oz. / 1.8 quarts, in a taller skinnier for factor. Has 3 SS inserts with screw threads on the mouths (but doesn’t show if they have lids or screw into the bottom of the next one up or what).

    Easily pack multi-part meals and keep foods separate until lunchtime with this large-capacity insulated lunch box from Kuuk.
    This container features double-walled vacuum insulation – superior technology to ensure your food stays hot all day long.
    3 separate compartments – Keep dry and wet foods hot in the same container, without mixing them together until you decide to eat.
    Only 100% food-grade materials were used in the construction of this lunch box, with a 304 stainless steel body and high quality silicone lid.
    58oz / 1.8 quart capacity allows you to pack multiple large portions or include extra snacks with your main meal.

    Also no idea how well insulated it is as they don’t say where it’s got any vacuum to it, or how much is the cloth over wrap thing. And just what is a “double vacuum” anyway/

    Product description

    Pack multi-part lunches and keep all your food hot, fresh, and separate until it’s time to eat!

    3-Compartment Lunch Box
    Pack up to 3 different foods in the same lunchbox together without mixing them at all. Each separate compartment in your Kuuk food container is individually sealed to prevent leakage, and ensures that at mealtime your food is just as fresh and delicious as when you packed it.

    Keeps Food Hot for Long Periods
    Double-vacuum insulation technology means this container retains a layer of air between its two stainless steel walls, not allowing the outside environment to affect the temperature of your food for long periods of time.

    High-Quality, Food-Grade Materials
    This container is made from 100% food-grade 304 stainless steel and silicone – only high quality materials that will never rust, bend or break with regular use.

    Pack Large Meals & Snacks
    This container features a large 58oz/ 1.8 quart capacity, meaning you can pack big and hearty multi-part meals for lunch or dinner. You can also use the extra compartments for snacks to accompany your main meal.

    Easy to Clean
    Your container is dishwasher safe and cleans easily in the top rack – with no dishwasher, simply wash by hand with warm soapy water in the sink.

    Some times the more you study the less you know…

  25. E.M.Smith says:

    Interesting gizmo. A small camping pressure cooker. From South Korea (and those folks generally make good stuff with decent design decisions).

    Claims 800 grams and 1/4 the fuel burn. At that rate 3/4 = 800 so 1/4 = 800/3 ~= 266 so if you would burn up about 1066 grams of fuel, using this would make it 266 grams and a net break even on weight. Don’t know how often folks carry 1.5 L of fuel, but…

    Size is about 8 x 8 x 6 inches and it has folding handles.

    Most importantly for me, it looks like a sane pressure regulation process. Having extensively reviewed the small pressure cookers, it looks like they divide into 3 groups, all “challenged”:

    1) Indian Style pressure weight. (What Hawkins calls their ‘new’ design). It doesn’t rock gently while cooking. It sits and sulks, then suddenly pops up and vents massively scaring the heck out of anyone in the kitchen, then goes back to sulking silently again. Repeat every many seconds… I have a Hawkins 1.5 L with this mis-feature and dearly miss my prior old “rocker” version.

    2) American Paranoid. The new designs usually with very fat handles and all sorts of interlocks to prevent you from being stupid. Including a thing that pushes the lid seal slightly out of place so it vents heavily before overcoming that spring, sealing, and raising pressure. (Comments usually indicate some folks ‘failed to seal’ as they didn’t have a 20,000 W burner under it to generate enough steam to get the seal to move while having a massive steam leak “by design”.) I have a newer “Presto” with these “features”…

    3) Computerized electric unified Grand Cookers. These seem to have all the quasi “features” of the #2 when it comes to “safety” but couple a computer control and electric built in heater so you have less you can do to fix things when it doesn’t work as desired, AND you get to try working around the computer “helping” you. I don’t have one of these and likely never will.

    So I’ve spent a few days, on and off, looking for a simple pressure cooker NOT equipped with 3 massive steam leaks “by design” and interlocks to thwart my ability to use the device; and without a computer; and without a “Whistle” style steam dumping jumping food exploding “Indian” style weight. I.E. basic kettle with seal and quite pressure HOLDING vent.

    This pressure cooker looks like that’s the case.

    Just can’t find any reviews of it anywhere. (They are likely all in Korean…)

    So guess I now just need to decide how much I care and am I willing to risk $75 to see if I’m right.

    I think I’ll try using my 6 quart Presto with the interlocks and pressure venting leaking seal again and decide if I REALLY want to cook something more in a pressure cooker. I’m hooked on the little one for Mashed Potatoes and what we call “Mashed roots” (lots of spuds plus other roots of your choice as available – carrots, turnips, onions, whatever. So far all have been good.) IF I find something else I really like to do in them, I could see this one as an improvement…

    So one of these (maybe) and then settle on some “slightly bigger than thermos” thermal cooking system and I’m set for a 1/3 to 1/4 of fuel needed multiple cooking styles life ;-)

  26. Larry Ledwick says:

    Reminds me of a story my Dad told. Right after he got out of the Navy at the end of WWII he briefly worked selling cook ware door to door. It was top line heavy aluminum cookware, one of their products was a pressure cooker which had the small rocker pressure control weight on the primary steam vent, and a secondary emergency blow out disk made of rubber in the lid. They cautioned the housewives to not over fill the cookers with products like beans which would swell and possibly block the pressure vent with the rocker on it.

    Seems one of their customers did not heed the warnings and put a bit too much beans and water in the pressure cooker and the beans expanded and blocked off the main steam vent with the rocker on it. Eventually it blew the rubber disk out of the lid.

    He said the inside of the pressure cooker was spotless and every single bean she had been cooking was stuck to the ceiling in the kitchen.

    That would have been some clean up job.

    As a result of that story I have always been cautious with pressure cookers. I have two different sized cookers but only intended for using on a stove top, way too heavy for camping like activities.

  27. E.M.Smith says:

    I’m very happy to have an over pressure blow out vent, and a rocker pressure regulator. I’m not happy with the “Whistle” style pulses of too much steam vent (and food expanding in the cooker) followed by too low too cool for a while as it heats back up, followed by another too vigorous steam venting…

    Near as I can tell, this is so poor Indians without a clock can ‘count the whistles’ instead of watch a clock and adjust the heat for a steady rocking weight.

    I’m also very much unfond of the “forced venting” (so folks can forget to vent the air out and only put the rocker on when it’s steam venting) to ‘protect me’ from too low a temperature in the cooking from air dilution. It requires HUGE fuel burn to make a LOT of steam to drive the seal closed against the spring making it leak.

    Oh Well. I just won’t buy any more of that stuff or I’ll make my own. (“remanufacture” to remove the perimeter spring added in the seal channel to meet the paranoia demands. Move a Presto “rocker type” stem and weight to an Indian “Whistle and splatter” lid. ) Or just buy sane products made by others…

    But having 2 pressure cookers I like, and 2 that are “OK But…”; I’m not interested in ever buying another of the “OK But”… (The 2 I like are old, pre-paranoia designs, and big for pressure canning… so not something to make 3 servings of mashed potatoes in them…)

  28. jim2 says:

    Video of the small Snowline pressure cooker.

  29. E.M.Smith says:


    Thanks for that video! It is exactly what I wanted to see (it works like I was hoping).

    Minor point: I think that’s their “large” one. It is taller than the small. Small one is 7.9 x 7.9 x 6.3 inches so H < D and slightly shorter than round. The "big" one is 7.9 x 7.9 x 7.5 so not as squat. Though the one in the video looks almost taller than round… maybe it's the handles…

    They also have a 'rice cooker' version at 805 grams that I think is the 7.9 diameter but shorter than the big one (no size spec in the listing so guessing from picture and weight). But with a picture that's more H than the small one. (or it could just be the picture angle)

    There's a portable "rice cooker" version listing at 2.4 L / 200mm x 200mm x 155 mm that I make to be about 7.9 x 7.9 x 6 inches and could be the same as the "small" one, but at a much higher price.

    Ah, found one comment where the manufacturer says the 200 mm is with the cover and actual pot diameter is smaller at something like 175 mm so “with cover” sizes above.

    I think they have the same product listed under a couple of names…

    Yes, more expensive ones found with a search on "Snow Line Pressure Cooker" while cheaper is found without the space "Snowline Pressure Cooker"…

    At $69 for the small one, and it being just about right for 2 people "on the go", AND with it being well behaved in terms of fuel use / venting; I'm pretty sure it's about ideal for me.

    Looked up some recipes in my pressure cooking book. Several Indian dishes, lots of "meat and rice" dishes, and some bean / chili dishes all look good. It seems you can also make bread in it (not browned much though…) and good with lots of whole grains.

    As one of my concerns is fuel needed to cook whole grains (think 12 gallons of wheat berries in #10 cans…) cutting that fuel to 1/3 or even to 1/4 is a big deal… That it's sized to fit a camp stove (or small household stove burner) is another plus.

    Match it with a similar sized "giant thermos" Thermal Cooker and you can use it to make slow cooker dishes too (where the pressure cooker is just acting as a regular pot to boil in). Nice when "hotel camping" as it's one quick heat, then just sits in the thermos until ready for dinner later…

    Overall, I think I'm sold. Just need to figure out which one and when…

  30. E.M.Smith says:

    So I decided to experiment with cooking dry beans in the thermos. Got it started, then discovered there’s someone already done it:

    I have one or two minor issues with their method, but nothing much. Mostly it has to do with the first soak. They have you heat water to preheat the thermos and then put in the heated mix of beans and boiled water. Then it sits for 2 hours as the “overnight soak”.

    Well, since the packages of beans say to just heat to the boil for 2 to 3 minutes, then turn it off and come back in 2 hours as the “fast soak”, I’m not seeing the reason to waste energy on preheating the thermos for the soak phase.

    They also used 3/4 cup beans for a 16 ounce thermos. Mine is 24 ounces. 50% larger. So that would be 9/8 cup. ( 6/8 x 1/2 = 6/16 = 3/8 ; 3/8 + 6/8 = 9/8) So I just used a cup of beans… Well, really, I’d already used 1 cup, then figure out what their ratio would be and noticed it was very close.

    As I usually cook a cup of beans or a cup of rice, I’m liking this 24 oz size thermos better ;-)

    So they basically do the usual “fast soak”, then a 10 minute simmer and a 3 hour slow cook.

    So far I’ve done the regular “in the pan” fast soak, a water change, then about a 3 minute boil and into the thermos at 11:am. Some time about 4 PM (or 5 hours) I’m going to check the status. Then I’ll either declare them done or do another water change / boil/ thermos until 6 or 7 pm.

    Even in the worst case of a soak and 2 x boil – I’ve used the water heat fuel + about 6 to 10 minutes of boil time. A lot less fuel than the same water heat + 2 hours of simmer / boil.

    I did forget to preheat my thermos, so I’ll likely check the temperature at about 2 PM and “top it up” if needed via a “dump in the pan, bring to the boil, back to the thermos).

    So, at this point, I’ve got basic “get it cooked” for both dry beans and rice with significant fuel savings. IMHO it is well worth it to put a good thermos in your emergency gear as a way to stretch fuel. That it also lets you “cook while walking or driving” is a bonus…

    I’ll update this comment in a few hours when I have some product to evaluate.

    Update1: Read their link on comparison of thermos bottles. Seems I have the worst one, the Stanley. I think I’ll do that ‘reheat’ in an hour or so in any case…

    Update2: At the 1.5 hour mark, the beans in the jug are 180F and an “escapee” bean (when pouring them back into the pot for a reheat) was soft enough to be good to eat. In an emergency situation, I’d call it cooked and start eating. I’m going to do a reheat to boil and back in the thermos for another couple of hours to test the other end of things.

    Update3: Heated to the boil and back in the thermos. I’ve added a tea towel wrapper and a couple of pot holders around the top. Took the liberty of a few spoons in a cup with some Filipino “banana sauce” (like spicy tomato catsup). Definitely edible, if a tiny bit more ‘stiff’ than the usual mushy beans.

  31. E.M.Smith says:

    Well, it’s 6 hours after the start time in the thermos, and about 4.5 hours after the “reload”.

    Beans measured 175 F, and are nicely cooked.

    OK, the technique is a “keeper” but this thermos needs a heat retention wrapping. (And I need a better thermos for longer term use…)

    This solves one of my major annoyances about the “buy a big bag of beans and rice”: The fuel to cook them. Running a burner for a couple of hours for every pot of beans is not a good way to conserve fuel. This does.

    Coleman 2 Burner Unleaded Stove

    I also cleaned up my old Coleman 2 burner unleaded stove. It has been “stored badly” for about 1/2 a decade. A few years of it under the Webber BBQ that had (unbeknownst to me) squirrels dumping sunflower seeds into the back of it. It was stuffed with a bunch of mouldering husks… After I got that cleaned out a year or so back, I was stored outdoors again (but without feeding sunflower seeds to the squirrels.)

    I found where the adapter had been put (to run propane). Under the brick BBQ (equipment shelf) in the back yard for a few years. It needed wiping with a sponge, and the attached propane canister has the paint starting to bubble on the bottom where water / condensation has been worrying it for a few years. Rinsed it all off, but did NOT dissasemble. Put it in the Coleman (just stick it in where the gasoline generator usually gets stuck and attach the spring to hold it to the case). Fired it up and made coffee ;-)

    Boils in about 1.5 minutes, whistles in 2, FULL 12 ounce cup, not the measured 8 ounces in other tests (why bother? I can measure under a minute with this clock…) Can you say fast? ;-)

    The can of Coleman Fuel that had been under the brick BBQ was rusty on the outside to the point of wondering if the handle would stay on or the top come off when I unscrewed the cap… (Hey, I got a call to “show up for a job pronto” and just had to bug out to Florida for 1.5 years… Some things had to just be left “as is” in summer mode…) The inside was fine and the (very old, maybe 8 to 10 years by now) Coleman stove fuel was fine.

    Doing this kind of “restart” reminds you why you want to check your gear. I spent close to an hour searching for one of my 3 fuel funnels. Found one, covered in 2 years of accumulated dust and grime. Cleaned and dried it, and filled the gas tank (and decanted the rest to a different container). Seems “things wander” if not kept in good storage order.

    The white gas burns with about the same power as the propane. I’m not going to test it, just use it. I want to use up this partial propane canister first and get it gone. (It’s about 1/3 full as when I left it, and I’d like it just used up and gone. Then I’ll use up the quart of white gas I’ve got and buy a new jug of it.) At most, I might need to replace the washer in the pump (but it seems fine) and / or clean out the orifice at the end of the generator – wrench off, thin wire, wrench on. I expect it to work fine. It has every other time for the 20+ years I’ve had this stove…

  32. Larry Ledwick says:

    I have been thinking about how to super insulate a thermos and today it came to me, – – – all those Styrofoam shipping peanuts you have to throw away periodically? Take your stanley thermos, fill as usual but also preheat the exterior shell with a bit of extra hot water, then put in a suitable cardboard box and fill to the rim with the packing peanuts. 3 – 4 inches of the peanuts should greatly reduce the cooling rate.

    Maybe throw in a space blanket wrap on the outside.

  33. ossqss says:

    Interesting on the thermos cooking item. I wonder if putting the item (probably a metal one) in direct sun would help, even at a right angle to the sun with a foil backdrop perhaps?

    I almost pulled the trigger on a coleman stove, but just couldn’t at $140 a wallyworld. Will wait for the sale day….. i am curious how your works when you get there after the lone hiatus.

  34. ossqss says:

    This stove looks mint for $50 (70’s vintage however), but the tank is in the cooking area unlike todays versions. There must be lawyer and idiots involved somewhere…. Thoughts?

  35. Larry Ledwick says:

    Paint the outside stove black and then make a little reflector box to sit the thermos in and you might actually get heat gain in direct summer sun, as a stagnant solar oven can get up to 300+ degrees.

    I briefly played with a micro solar oven with 4 each 45 degree reflectors on a box that was only big enough to hold a soup can or single serving can of pork and beans. In direct summer sun they can get the contents up to serving temperature but you want to punch a small pressure bleed hole in the top of the can to make sure you don’t get a steam explosion if it is left too long.

    If you pre-heat the solar oven with a couple bricks in it you could probably slow cook in a mason jar.

    My design was really small but very similar to this design.

  36. Larry Ledwick says:

    That old style gas stove works fine, cooked quite a few meals on one. The external tank is a bit more convenient to deal with but that old vintage stove would work just fine if the seals on the pump and pressure lines are good.

  37. E.M.Smith says:

    Amazon has it at $126 or this one at $96.

    That looks to me like the same thing with a discount price. Would want to check what makes the “Guide” series different from the “Powerhouse”.

    Frankly, were I doing it again, I’d likely get 2 of these instead:

    Buy one for $70, then when you are comfortable you like it and decide you want more, but another. Now you have redundant tanks, valves, generators, etc. You don’t get the built in wind screen though. But on the dual burner, the 2nd burner never really gets to full power. Gas must pass by the first burner to get there and it’s just lower pressure when it arrives. With 2 of the singles, either burner can be any power.

    Then again, I’m also really really happy with one 2 burner and one single burner… Some times you just want 3 burners…

    Per solar heated thermos:

    Insulation works both ways… Not going to solar heat well at all. MIGHT slow heat loss, but really it’s convection that’s the killer. I’d rather just shape a styro-chunk and be done.


    The peanuts is a good idea. I was thinking 4 inch insulation styrofoam and cut to blocks to fit (or a set of rings to slide over it from the top…) Cheap. Easy. Needs a bread knife to do it right ;-)

    But really, the tea towel worked fine and a regular bath towel would be overkill… but I like overkill ;-0

  38. E.M.Smith says:

    The tank is STORED inside. You lift the grill, pick up the tank / generator, stick the generator tube into the hole in the front / right (next to the handle, you can see where it seats in the back under the grill as a round dark spot) and the ‘tabs’ on the tank into the two slots, then lower the grill. Pump, open valve, ignite, wait for generator to get hot in yellow flame, adjust to blue…

    The old red tank stoves ONLY burn White Gas. The newer ones can burn white gas or unleaded gasoline (grey tank). At $8 / gallon for the no name brand of white gas at Walmart, vs $3 / gallon unleaded, in 10 gallons you have saved $50. (but may need to clean the generator tube out. I have not yet.)

  39. jim2 says:

    This is cheap, flat, and easy to pack.

    If the focus isn’t too sharp, it could easily heat up a thermos with good sun.

  40. ossqss says:

    Interesting that single burner unit has a 10k btu output vs 7.5k btu on the primary burner with 2. I gotta get my hands on the neighbors for testing. That will cost me beer though ;-)

    Thanks for the feedback.

  41. E.M.Smith says:

    Um, you can play with ALL my stoves for beer…


    FWIW, I’ve only used the 10k BTU getting a big pot of water to the boil. Most of the time it’s lower. The 7.5K BTU make hot more than quick enough for anything but BIG pots.

    Also note that the single burner you get a little more “balance the pot” challenge while the 2 burner it’s easy to “plop a pot and no worries” but you have “issues” if you put a 12 inch frying pan on the main burner and want to put a pot on the second one…

  42. E.M.Smith says:

    RV places sell large Fresnel lenses to put in the rear window as Bug Spotters… Don’t know the price. Some are pretty darned big.

  43. ossqss says:

    EM, perhaps when you come to Florida we can make that beer item happen. I ain’t goin back to Cali for anything after all I read, and you shared.

    Queue up L.L. Cool J “Goin back to Cali”

  44. E.M.Smith says:

    Deal! (Loading car shortly… will drive for beer ;-) /humor; of course…

  45. ossqss says:

    Ha! The offer will always stand with no time limit! ;-)

    Interesting short story. I moved to SW Florida in 1986 from Pittsbugh. Within 6 months time, a good buddy (Head Chef at a nice CC) came to visit for a week. We caught lots of fish and other 2 legged prey. I told him to feel free to come down and stay with me if he wanted to look for a job here anytime, as he was boarding the plane. A week later, there was a beep out front with a car and Uhaul trailer following it into my yard. It took him a year to find work, but it was hard to find work when you fish everyday and chase tails all night! LOL

  46. jim2 says:

    My wife and I got welder’s helmets. We are going to pull out the 3’x4′ (or so) FL at some point and try melting some aluminum cans.

  47. E.M.Smith says:

    Well, to save us all the suspense, and as my coffee was gone and the stove cooled, I just went out to the patio and fired up the Coleman on old stored Coleman fuel. Worked perfectly first time, both burners.

    There are a few worn / bubbled spots on the outside paint (where it sat in damp squirrel spittle covered sunflower shells for a year or two in the dark…) so now on my “someday” list is to lightly sand those places and spray it with something heat resistant and hopefully green. Wonder if Rustoleum makes green ;-)

    It’s now going to be my “main stove” for Spring / Summer.

    Why? Well, first off, I’ve got about 1/2 gallon of old fuel to use up that’s presently in the tank and an old Bullit Rye bottle… (I didn’t trust the can…) And that dodgy propane canister to finish.

    Then the Spouse has started baking again, and that she likes to do right when I ought to be cooking dinner. Easier to use different spaces.

    Thanks to the Redwood Trees Demise, I now have a very nice 1/2 log Redwood Bench on my patio… and when it isn’t raining , the dogs and me like to sit out there anyway, so… combine some work and pleasure…

    Then there’s just that whole “playing with fire” thing to enjoy ;-)

    Plus a couple of times trying to make a pot of something on the Trangia, it’s been just a 1/4 inch move of the pot to unstable land. The heavy wire grid on the Coleman is “plop pot and no worries” and having almost caught a pot of tortellini on my toes (but caught the handle in time instead) I’m no longer using my small (quart?) pot on that stove. Tea kettle, fine. Bigger pots, fine. small cast iron skillet, fine. just not THAT pot…

    Oh, and lighting it the instructions say to use a match. You CAN do that, though it’s easier if the grid of wires is off when you do it. Better is to get a BBQ / Fireplace butane lighter (with the 9 inch length kind of thing) and just spark it. I like them with butane in them best, but when it runs out it still works as a sparker.


    FL ?

  48. ossqss says:

    FL, my guess would be Fresnel lenses based upon the above, but I don’t want to put words in jim2’s text box.

  49. E.M.Smith says:

    Ah, that would make sense. Need welders glass at that light intensity… So a 3 foot by 4 foot Fresnel lens? Oh My God! We’re talking about a square meter or roughly kW of power in a spot the size of a coin… Any ant colony near by? ;-)

  50. E.M.Smith says:

    Made a comment HERE:
    that likely belonged here…

    It was a test of a single burner propane stove that made a 12 ounce kettle whistle in 1:15 so would be an 8 ounce standard kettle to the whistle in 50 SECONDS.

    Anyone who want fast easy low cost low fuss camp cooking ought to get one of these for all of $30:

    It is done heating the coffee water to a boil while you are still pumping and preheating the gasoline stoves. (Though playing with fire is more fun with the gasoline ones ;-)

    Also of note: I re-figured how long the old propane canister and adapter were stored “in the rough” and how long my 2 burner Coleman Unleaded was in Squirrel Hell. More like a little over 3 years. My contract was 1.5 years (and I bugged out to Florida a week before it started) then I’ve been back here roughly 1.5 years since it ended ( about 20 to 30 days short, maybe). So that’s at least 3 years, and I had the stuff “stored outside” before that bug out. I think since roughly that Spring which I think started about March.

    The Coleman was banging around on the back patio for a couple of years before that… so all up about 1/2 decade

  51. Larry Ledwick says:

    I picked up one of these Thermos brand food jars today and will play with it a bit to see how well it works. It includes two microwavable 20 oz food jars that just fit inside. It is supposed to be able to keep food hot for 10 hours. I will have to tinker with it at home but it might hold a pint wide mouth mason jar from the looks of it.

  52. Larry Ledwick says:

    I just checked that Thermos ™ brand 47 ounce food jar I linked to above.

    It easily accepts a 1 pint mason jar
    It accepts 2 of the short squat 500 ml mason jars but you can’t quite get the insulated lid to fully seat.
    It accepts a 1 qt wide mouth mason jar but the insulated lid will stick up some and not seal (the two 500 ml jars almost let it seal

    It would be pretty simple to make a custom plug top for it by putting the 1 qt jar in it and then push down some saran wrap with the insulated lid then carefully remove the lid and fill the saran wrap with urethane foam or cut some plugs of insulation board and fashion an insulated plug that way for the special use case of a 1 qt wide mouth mason jar.

    Might be sufficient to just stuff a rag in the top and put the outer top on it for that matter.

    I will do some real thermos cooking later to follow up on how well it keeps heat.

  53. Larry Ledwick says:

    correction got it backwards, the wide mouth quart jar will let the insulated plug drop almost all the way into the sealed position ( a few wraps of electrical tape around the lid would let it actually seal)

    On the 2 500ml jars they sit almost flush with the top so cannot insert the insulated lid at all, but the top lid will go on just fine with perhaps a rag stuffing for insulation.

    For now my first test I will fill it with boiling water (after pre-heating the thermos with 130 deg hot tap water) and see how it cools down.

    (interesting feature, the top insulated inner cap has an air bleed hole that is exactly the right size for small cooking thermometer so you can measure the temperature of the contents without removing the insulated top. [ bad news the cap is not water tight due to that air bleed hole so will need to be kept upright or some sort of 1/8 inch diameter plug inserted in that bleed hole ])

  54. jim2 says:

    Yes, FL = Fresnel lens. I measured it just now, it’s 2×4 feet. Came off a projection TV, the old ones with 3 CRTs, lot’s of lenses and filters. My wife and son picked it up off the curb of someone’s house because they know I like to scavenge parts. The FL was a pleasant surprise. Son and I tried it out. The focused spot is too bright to look at comfortably.

  55. Larry Ledwick says:

    Early results from the 47 oz Thermos food jar.

    I pre-heated the jar by running hot tap water into it for several minutes, then pouring the water it contained into a small stew pot and bringing it to a boil.

    A couple of observations from that process. You need to pre-heat these metal thermos bottles for a reasonable period of time because there is a very significant drop in content temperature in first 30 minutes or so after you fill them as they heat up the interior of the steel bottle. Then once they get to a stable temperature about 30 minutes later they settle down to a more uniform cooling.

    140 deg F pre-heat is not hot enough to properly pre-heat contents at boiling temps.

    Here are the times and temps. I found a big difference in temps recorded by my little food thermometer and my IR thermometer and decided to do most of my measurements with the IR as it is much quicker and also gives consistency with the temps I took of the exterior of the Thermos bottle.

    Times are clock time, not time elapsed from filling.
    time . . . . . . IR contents . . . exterior body . . . top
    00:18 . . . . . 182 F. . . . . . . . . . . . . . . . . . . . . .
    00:25 . . . . . 177.3 . . . . . . . . . 76.8 F . . . . . . 89.9
    00:55 . . . . . 170.0
    01:55. . . . . . 166.9 . . . . . . . . .74.2 . . . . . . . 95.8
    02:55. . . . . . 166.6. . . . . . . . . 74.2. . . . . . . . 94.8

    06:55. . . . . . 154.9. . . . . . . . . 74.2. . . . . . . . 89.8
    07:55 . . . . . .149.4. . . . . . . . . 73.4 . . . . . . . .88.9
    08:18 . . . . . .148.9. . . . . . . . . 73.4 . . . . . . . .87.6

    At this point it is clear that there is a major heat leak at the lid. Part of this is due to the air bleed hole in the inner top plug and the fact it was filled with boiling hot water, so that water vapor can freely convect through that hole to heat the inner surface of the stainless steel cap.

    The interior liquid lost 12 degrees in just the first 37 minutes heating up the inner liner of the thermos jug and its inner cap. The body of the jug seems to have very good insulation as it quickly reached and held a stable room temperature, while the stainless steel top cap quickly heated up to 15 degrees over room temperature.

    Next time I will pre-heat the bottle with boiling water after the hot tap water pre-heat, and will place a seal over the top air bleed hole to minimize water vapor heat transfer by heat pipe action to the outer stainless lid, and later a top cover like a folded towel over the top of the filled jug to minimize heat loss through the lid.

  56. Larry Ledwick says:

    Okay final temp set, that Thermos food jug is rated to keep food warm for 10 hours according to the lables, and it appears it does, as at 10 hours since filling it with boiling hot water the water is now at 141.6 degrees (just about perfect soup stew drinking temp)

    I am going to fiddle with different pre-heat methods and a cover during its standing period and see what I get without opening it frequently for temperature measurements.

    But based on this first test I can recommend the 47 ounce Thermos stainless steel food jug for use in thermos cooking type uses up to 10 hours.

  57. Larry Ledwick says:

    Okay update with new procedure at 10 hours:
    I changed a couple things on this test
    1.) I prepared boiling water about 1.5 x the contents of the thermos jug.
    2.) I pre-heated the interior with hot tap water for a few minutes, then dumped it, and poured 2/3rds of the rolling boil water into the thermos and left the remaining 1/3rd on the stove.
    3.) I let it heat soak for 10 minutes then dumped the hot water out of the thermos back into the pot, and quickly covered the thermos jug.
    4. I let the pot of water on the stove come back to a full rolling boil then poured the boiling water in the the thermos jug and quickly capped it.
    5. I fashioned an insulated cap out of about 4 layers of bubble pack and a sleeve of bubble pack to form an insulating top hat for the outer cover of the thermos jug.
    6. I then draped a couple dish towels over the whole affair and let it sit undisturbed for 10 hours.

    After 10 hours I pulled the top insulated over coat off the top and using my IR thermometer I measured the top of the outer stainless steel cap. It was at 106.6 deg F. This tells me that
    a) The cap of this jug is not nearly as well insulated as the body,
    b) my little expedient insulated Dixie cup over coat for the lid works fairly well for insulation.

    The outer shell of the body of the thermos jug was at 76.1 deg which is only slightly warmer than the stabilized temperature of other objects near it which were at 75.1 deg F, so heat leakage on the sides of the jug is nil.

    The internal temp of the water in the thermos just was still at 152.1 almost 10 degrees warmer than the contents of the bare jug was at 141.6 after the same time interval.

    Good preheat methods and extra external insulation for the top plug and cap made an 11 degree difference in contents temperature after 10 hours.

  58. Larry Ledwick says:

    Another minor update, now at 12 hours since filing the 47 oz thermos jug, The following data:

    Top 96.0 deg F, side of jug 79.8 deg F, contents 146.4 deg F

    It appears at this stage it is losing about 3 deg F of contents temperature every hour so it will reach 140 deg F (which I define as the point where it begins to be too cool ) in about 14 hours total when in a room temperature environment.

    I guess in the next few days I will try cooking some rice and beans in it’s two 500 ml jars and see how that works out.

  59. E.M.Smith says:

    Great info!

    Rice is easy. My beans were good but I need to try a non-reheat method… OTOH, changes of water reduce gas so maybe reheat is better except in horrible fuel shortage situations.

  60. jim2 says:

    In the wild, one could put water in the thermos, heat smooth rocks on a fire, and drop the rocks into the thermos. After a while, drain water, remove rocks, replace water in thermos, apply more hot rocks.

    Or, just fill thermos with hot rocks, seal, let it equilibrate.

  61. Larry Ledwick says:

    I just took a 16 hour temp on the thermos food jug.

    Top 98.4 *
    side of bottle 75.1
    contents 138.9

    * In my haste to get it capped for the prior test ( 22:08 – 00:08) I left off the little extra insulation cap fabricated from bubble wrap, I put it back on for this last 4 hours.

    We have a proven ability to hold food hot for 16 hours here with very simple techniques.
    The pre-heat method and the supplementary insulation for the top caps being key to long keep times.

    Keep in mind that this is at almost 6000 ft altitude so my initial boiling water is actually cooler that yours would be near sea level. Here where I live boiling point of water is 200.6 deg F.

  62. E.M.Smith says:


    FWIW, the “slow cook in steam table” and “minimum to kill microbes” temp is usually held to be 160 F. I suspect 140 F would be “close enough” as there is a margin for error in the recommended temperatures.

    In the restaurant things would “slow cook” in the steam table. (A roughly 3 foot x 6 foot x 6 inch deep puddle of water – with fire under it – in stainless steel into which one set those flat steel pans that you also see at buffets over Sterno warmers in single pan holders)

    Since most slow cook recipes run 6 hours on high or 10 hours on low, (and for the thermos the end of 10 hours is near the lower bound temp and the start is above the high) I think you’ve shown it to be an effective ‘slow cooker’. IMHO all that’s needed is to slightly vary how long a food is simmered prior to the pour in. That ought to let you adjust for things like “chunk size” and toughness. (Big chunks take longer to warm through. In a constantly warming slow cooker you just wait longer, but in a constantly cooling thermos you would need to heat to the center first. I usually just chop into smaller chunks if I want a faster cook. Think Potatoes. One hour for whole potatoes at the simmer / boil. About 15 to 20 minutes for modest dice. Small dice closer to 10.)

    In a real Aw Shit Scenario I’m sure folks could figure out ways to not waste the pre-heat water energy. Say, boil a thermos of water and pour in to pre-heat. Prep food and simmer the starting length. Pour out thermos water into pot for making coffee and set on stove while taking food pot and pouring into thermos. Cap and insulate thermos while sipping coffee made from the preheat water.

    On the Stanley, it is hot to the fingers around the join of the cap to the bottle. That’s where the heat inside can follow a metal path to the outside. Yes, thin metal, but metal all the same, so good heat conductor. I suspect that is where the glass thermos wins the heat loss race. For now, I’m happy to just wrap it in a towel. At some future time a Styrofoam or similar top cover would be a nice to have. There are also fairly cheap “coolers” that are basically round canisters of foam. I might look for one of those instead of cutting Styrofoam board.


    About $15 and you get lots of nice fitting closures. Pour your packing peanuts in any gap space and it ought to work quite well… or a chunk of bubble wrap.

  63. Larry Ledwick says:

    Yes that is what I have been thinking as well. Since you are coming down from a temperature that is clearly safe, well above pasteurization temperatures, after a couple hours you can presume the contents are essentially sterile.

    In a survival situation of course better safe than sorry given medical help is not available as it would be in normal times. Small food piece size would be good both to ensure cook through but to aid digestion.

    The other consideration if you are well equipped, is to use your small pressure cooker for the initial heat and bring the food to the 15 psi point for just a couple minutes, then turn off the heat and as soon as pressure drops to ambient pour into the thermos jug to finish hydrating and cooking. That way you have much greater assurance that any large pieces of meat are thoroughly heated to at least minimum temperatures. You would probably use less fuel the long run to pressure cook for 3 minutes rather than rolling boil for 10.

  64. Larry Ledwick says:

    As mentioned in the second link you could also use the thermos as a method to provide long term storage of perishable food, by stopping and re-heating the food every 12 hours or so. This would provide a means to extend the edible use time of food out of a fridge that no longer has power. In the Military survival manual they recommend this method of keeping food like a stew or soup by boiling it in a covered pan at least once a day.

    You could also change the pre-heat cycle to be part of the re-heat cycle.

    Boil the food and place in a room temperature thermos.
    Let the food sit for a couple hours ( it will rapidly cool to about 175 degrees heating up the thermos to a stabile high temp through out)
    At 2 – 3 hours re-heat the food to boiling and pour back into the heat soaked thermos. This would avoid having to heat 2x the water volume, so you would not have the extra hot water to deal with.

    As always different use case might drive different techniques for different situations. Short supply of water use the double heat method, ample water supply use the heat 2x the water and find secondary use for the pre-heat water like coffee tea or hot chocolate.

  65. Larry Ledwick says:

    Well just to close the loop for information purposes, at 24 hours after filling that 47 oz Thermos food jug has the following temps

    lid (with use of the extra insulation cap and towel cover) = 91.7 F
    body temp = 73.7 deg F
    contents = 126.0 ( still warm enough to eat but not ideal from a food safety point of view.)

    Any sort of second heat a few hours into the test would have maintained food temps over 140 deg F for over 24 hours at ambient moderate room temp conditions.

    I will have to make up a custom super insulated carry bag for this and see how it goes. Ideal would be to find a metal container that just slides over the outside of the jar, perhaps one of those stainless steel canisters used for the kitchen counter to store flour etc. Then you could have a nested set that allows you to pour out the contents and put it on the fire to reheat then pour the contents back into the thermos jug after bringing it to a boil.

    That would take a canister or small deep pot with an inner diameter of 5 3/8 – 5 1/2 inches minimum.

    Lucky me – I already have a suitable container: an empty #10 institutional size can works perfectly, just wide enough to accommodate the pivot bolsters on the carry handle.

    Line the # 10 can with a single layer of 1/4 inch bubble wrap and you have an insulated outer cover for the whole kit. To make it totally encased, you would need to cut a second #10 can down to about 1/2 height (just a tad less than 5 inches deep) to make a matching top for the assembly.

    Now all I need is to make a super insulated carry bag to go over the set.

  66. E.M.Smith says:

    On a whim at Walmart (while buying white gas at about $7.50 / gallon and cheap methanol) I bought a 16 ounce Thermos brand wide mouth “food jar” in the camping department. About $15.

    It was a mistake.

    It has a folding spoon that clips in the cap. Fine, I figured I could ignore it. Nope. Falls out most times the jar tilts too far or is inverted.

    The stopper has a modest chemical resin smell. I think it is the plasticizer. Bis-Phenol-A anyone? Washing reduced it some, but did not eliminate it.

    Loaded with vegetable curry at the boil, 8 hours later it is 125 F. The cap feels warm when first loaded. More insulation and less metal spoon would be better.

    Clearly designed to be loaded at breakfast and emptied 5 hours later at eating temperature… despite claims of 10 hour keep warm times. Then again, I suppose 110F is warm, for some definition of warm…

    Made in China. IMHO it shows. The poor fit of spoon to clip. The stinky plastic.

    I’ll find a use for it, though. Would make a nice worm tub when fishing…

    Note that Nissan THERMOS is a different company from this one.

    On another note:

    Visited the Japanese grocery megamart. They had a few of the multi-bowl lunch carriers. Physical inspection was very helpful. NONE of them had a good insulated stopper. They will keep warm until lunch, but not to cook in. Maybe some other brand might, but investigate the lids closely. I didn’t buy any… Sides were well insulated vacuum bottles, making the thin hollow stoppers more inexplicable.

    I’m happier with mt Stanley now. No funny smell, states BPA free on the wrapper, pretty good stopper. Just add tea towel wrap to cook…

  67. Larry Ledwick says:

    Hmmm I just picked up the 27 ounce Thermos brand food jar (have not tested it yet).
    This one has no noticeable plastic smell on the stopper, (at least to me). Both this size (27 oz) and the earlier one I tested (47 oz) list as made in china.

    It is rated to keep hot for 8 hours.

    I got to thinking there is clearly a trend to shorter keep times as the jars get smaller, it might just be due to the square/cube problem, that surface area relative to volume is greater on the smaller jars than the larger jar.

    They do tend to keep cold foods cold longer than they keep hot foods hot, so might be useful for Ice tea in the summer or something.

  68. Larry Ledwick says:

    By the way I have had pretty good luck getting rid of that plastic smell / taste in containers by filling them with hot tap water and letting them set for a day then repeating a couple times.

    Let what ever it is diffuse into the water fills. I think it is the mold release agent but seems to go away after several water changes. A pinch of bicarbonate of soda might help too.

  69. E.M.Smith says:

    I may have (read did) over reacted to a bit of smell, and had some mal-technique on my part.

    First off, the spoon. IF you place it carefully and press so it aligns Just So, it stays. I’d been doing “put in place, push and move on” that doesn’t get it lined up right to stay. So I’d count this one 50 / 50 design not so good / customer error.

    On the Stinky Bit: I’ve done a hot soapy wash, and an ammonia wash, and a 10 hour hot curry soak. Now it doesn’t much. Bear in mind I have a cold at the moment and my smeller is alternately plugged up some or drippy; so this reprieve may be short lived. We’ll see.

    I’d had a prior expensive coffee thermos ( I think I bought it at Starbucks) about 20 years ago with the same (or strongly similar) smell; where weeks of various attempted processes did not cure it. Every liquid cleaner I had. Beach. Vinegar. Ammonia. It eventually sat on the shelf for about a decade then I’m not sure where it went. It also made the coffee taste funny… So I figured this would be the same. Potentially this is a “my bad”. Like I said, we’ll see.

    It still loses heat faster than it ought. Yes, there is a cube / square issue; but when first filled the join of cap to body is VERY WARM indicating heat loss. A better plug and cap could cut that a lot.

    On cold vs warm times: Remember that the thermal gradient on cold is going to be about 20 C and max about 30 C for frozen to normal peak daytime. The hot to cold gradient will be 70 C to 80 C for boiling on pour to the same normal daytime peak. Different problems… Open question is how cold is still cold enough vs how warm is still warm enough.

    So at this point I’m moving the potential uses up from “cool worm hotel” (which is still a feature I want, BTW) to ‘drink glass’ for hot summers in Florida where the vacuum flask part will keep condensation from making my wine cooler a wine warmer… and you can put a plug in it if for some reason you are taking a break (going to float in the pool a while…). IF the plug becomes civil enough, I can also see using it for ice-cream at the pool (then the spoon would be a feature), and even a curry caddy. I make batches of curry that are a bit big to eat all at once, but like to have at least 2 servings a few hours apart. One in the bowl, one in the 16 oz thermos and the rest to the fridge will solve some logistics issues. Basically using it more or less as designed, for a 5 to 6 hour offset of meal from make time. Could even see doing the same for chili. Then there’s carnitas. I like to make burritos carnitas but it takes time to assemble each one. Put some carnitas in here, and then the refritos in a skillet as they ought to be, the rest is cool stuff. One burner only needed to heat the refritos, warm a tortilla, and then assemble without needing a big carnitas pan on the stove too. (I could someday see a second 16 ouncer of some make for the refritos for “burritos on the run’ ;-)

    So OK, as of now I don’t hate it any more. I don’t love it either. But it’s stopped growling and snapping at me and only barks when I first enter the room… so maybe we’ll learn to be friends… If I let it do what it likes to do, and stop expecting at it…

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