Reading the idea that a drained "pouch" of tuna would weigh twice as much as a "can" of drained tuna set some bells off in the back of my feeble old brain - especially based on the idea that a pouch cost twice as much as a can .. that could only mean one thing ... a 3-oz pouch vs a 6-oz can at regular premium prices. Time to head to the store, and the kitchen to check this out - and seperate fact from myth. (Yes, I've been watching way
too much Alton Brown.)
The first problem was to seperate the "extranious" (added) liquid. Obviously my first choice to seperate liquid and solid matter would have been a centrifuge ... I don't own one .. and it would have also been overkill - it would have extracted more than just the added liquid. Second choice ... a salad spinned ... don't have one of those, either. So - it's up to mother nature and gravity.
For this experiment I went with tuna packed in water since the water would drain better than oil since it is less viscous - and I was going to have to work with gravity only to seperate the excess moisture from the solids.
EQUIPMENT: a Soehnle analog (spring) scale, a 100ml Pyrex (ASTM Standard) graduated cylinder ... 3 Gladware bowls and 3 medium-mesh strainers ... and some Saran Wrap.
(1) I weighed 3 cans each of Bumble Bee, Alberton's brand, and Starkist tuna were weighed. In all cases, 3 cans of any given brand weighed 21-oz (7-oz each).
(2) A strainer was placed in bowl and a can of each brand of tuna was opened, dumped into the strainer, spread out a bit with a fork, and the can was inverted over the top of the tuna to allow any residule moisture to drain out. This was covered with Saran Wrap (to cut down on my 'fridge smelling like tune and to reduce evaporation) and placed in the refridgerator for 24 hours.
(3) At the end of 24-hours ... the cans, tuna, and drained liquid we weighed .. the liquid was also measured in the graduated cylinder.
(1) An unopened 6-oz can of tuna weighs 7-oz. The cans weigh 1-oz.
(2) Among the 3 brands I tested ... Bumble Bee had the most water (45ml - 3 Tablespoons). Albertson's brand had slightly over 2-T (38ml), and Starkist was right at 2-Tablespoons (32ml).
(1) The idea that a 3-oz pouch of tuna, when drained, contains twice the amount of a 6-oz drained can of tuna .. well, it doesn't hold water. A 6-oz can of tuna will yield about 4.5-5 -oz tuna (depending on brand).
(2) I didn't test "pouch" tuna ... I'm sure that they would contain "some" excess water .. but didn't want to pay the $1.39-$1.79 per pouch to find out the exact amounts.
A 6-oz can of tuna that cost about 50-cents and yields about 4.5 oz tuna is probably a better buy than a 3-oz pouch that costs about $1.39!
There is a difference between taste and economy .. and utility. If you like the flavor of the pouch better .. than by all means, buy what you prefer. To me, the way I use tuna most often (mixed with mayo, hard boiled eggs, onions, garlic, apple, lettuce, chopped pecans for a sandwich -or- mixed with pasta, cheese and peas for a casserole) , it would be wasted money to buy the pouch because I probably wouldn't taste the difference.
Anyway ... that's the observations from this "curious cook's" kitchen on this subject.
And - I still prefer tuna in oil over water