I tend to buy different canned tuna at different times. Price is important, but so is the quality in a sandwich.
I was peeved when they shrunk the can from 6 ounces to 5 ounces “net”. Then some brands are more mushy than others so don’t make as good a sandwich. Looking into it, I found that the way compliance with label regulations was tested was the “drained weight” and that was found by some standardized draining method with a set force.
Well, if you know your physics, you know that surface tension causes liquid to cling to surfaces. The more surface, the more clings. Chop your tuna into dust-mite sizes, you can put less actual tuna in each can. For this reason I avoid the ‘whatever’ brands that sell you cans of mush for cheap and buy “name brands”. Now imagine my surprise when one of them, when opened, seemed to have a deeper puddle of liquid on top of the tuna than the other.
How much? I wondered.
So I set up the food scale ( 1/10 ounce precision ) and two sandwiches later, I have my answer. StarKist Tuna shorted the can by 1/2 ounce compared to Chicken Of The Sea.
Digital Kitchen Food Scale – automatic tare on bootup
1 – 5 ounce can of Chicken of the Sea “Chunk Light” – packed in oil (water pack is for wimps!)
1 – 5 ounce can of StarKist “Chunk Light” – packed in oil
Plastic perforated circular hand press ring thing designed for draining tuna (yes, folks sell those!)
Standard press weight – 48 ounce plastic jar of Apple Sauce – Great Value (Walmart) brand.
Standard glass bowl for mixing tuna and as tare container for naked tuna weight
Note can brand, and declared weight (net and drained) in notebook. Weight at each successive step of decanting and pressing and note in lab book. Set tare at each weighing to zero, measure, record, repeat until final step of putting fully drained tuna into the bowl (tare set with bowl to zero). Record final weight. Make sandwich and eat.
Measurements taken for:
Lid removed can
Pressed for 30 seconds with the 48 ounce weight and plastic press element inserted into the can.
Pressed with the same hand press unit using my full hand strength (not much left after that but dry tuna)
Tuna decanted into bowl (tare set with bowl to zero)
Chicken O.T. Sea StarKist 5 ounce 5 ounce Label Net Weight (142 g) 4 ounce 4 ounce Label "drained" Weight (113 g) 6.1 ounce 6.2 ounce Full can - unopened 5.8 ounce 5.9 ounce Lid removed 4.7 ounce 4.2 ounce 48 ounce press for 30 seconds 4.2 ounce 3.7 ounce Full hand strength press to the point of no more liquid available 3.4 ounce 2.9 ounce Tuna decanted from can 0.8 ounce 0.8 ounce Empty Can
My 48 ounce press seems to come close to the “official drained” spec, so I don’t think they are cheating. Well, not in terms of legality cheating…
But the Chicken Of The Sea can held a full 1/2 ounce more tuna under those conditions. At full press, it was still 1/2 ounce more, so I think that’s pretty good evidence that it was tuna in both measures showing up as the added weight.
Now a half ounce out of a 12 ounce can of commercial restaurant tuna would not be as big a deal. Even out of a 6 ounce can of tuna, it’s 1/12 or about 8% and not a crucial thing. But when you only have 4 ounces of tuna in the can, that’s a good 1/8 or 12% and we’re starting to reach definitely noticeable shortage range (hey, I noticed it just looking at the puddle in the can). Then when you are down to only 3 ounces of actual tuna in a can of tuna, that 1/2 ounce is 1/6 of the load. We’re talking 16% and that’s a LARGE percentage shorter.
So, for me, I’m going to be preferentially buying Chicken Of The Sea when given the choice.
At some later time, I’ll repeat this test on other brands (including a couple of ‘house brands’). If anything pops up that’s interesting, I’ll add a note. Right now I’ve still got a dozen cans of StarKist and Chicken Of The Sea to work off. I did this test just after stocking up on a monthly grocery run… Of course, if anyone else has a kitchen digital food scale and likes to do a bit of literal “Kitchen Science”, feel free!
Gee, kinda reminds me of that whole VW thing of manufacturing to meet the “spec” of the test, not the actual performance of the product…
Though I’m sure StarKist will say it might have been a bad batch or that 4.2 ounces is over 4 “drained weight” so legal, or whatever… It doesn’t matter. What matters is that being skeptical, doing your own measuring, and comparison shopping gets me 1/2 ounce more tuna in each can.
I’m OK with that…