Among the major problems encountered after a serious flood there is the minor problem of salvaging or not, the perfectly safe food in hundreds of thousands of tins without labels.

Challenged to find a better method than "suck it and see" I could only come up with Archimedes' discovery of specific gravity and long lists of foods to match s.g. reading with.

My grand-family laughed me out of the house and returned to the serious buisness of mud-shovelling as I shuffled back to my taxi and the Halfbakery.
-- rayfo, Dec 18 2000

Scrapheap Kitchen Challenge http://www.halfbake...Kitchen_20Challenge
Or sell them to this show's producers. [Monkfish, Dec 18 2000, last modified Oct 17 2004]

Don't feel bad rayfo... your genius is fully appreciated here at the halfbakery.

And, uh, let us know when that s.g. list is ready...
-- PotatoStew, Dec 18 2000


While not nearly as nifty... the canned goods currently in my house have dot-matrix printing on their lids, not immediately water-soluble; some of them look like date-and-machine numbers, some have more codes. Surely the codes could be expanded to plant-and-machine-and-date, and lists maintained of which plant canned what when, so that a squalching householder could just search for the numbers and find out what the can had.
-- hello_c, Dec 20 2000


Marketing rule of thumb, weigh all the cans. If you find a disproportionately high number of one can type--those are the tomato soup. In the future, twist off lids for just this type of disaster.
-- reensure, Dec 20 2000


There is no way that those labels are going to come off.
-- Vance, Jan 30 2001


I don't think that specific gravity would work since it is a closed system with a fairly standard size and shape and near-uniform weight. I mean, the specific gravity of a 454gram can of soup is going to be the same as that of any other 454gram can of soup in the same size / shape container.

Ultrasound may give you a pretty good idea of the air space in the top, as well as possibly some other characteristics of the contents. You might be able to seperate cans into lots such as "We're 80% certain that these are tomato soup, but there's also a percentage chance that it's vienna suasages, or split pea soup" then sell them at a reduced price for the uncertainty factor.

heh. Schroedinger's soup.
-- Rant93, Jul 24 2001


To expand on hello c's idea, why don't canned food companies fire dot matrix printing of the contents onto the cans? Get rid of labels, even. That way, all cans are labelled, and costs for the manufacturer are likely down due to not having to print up a bunch of garish, multi-coloured paper labels for their products.
-- lewarcher, Oct 14 2001


Labels are supposed to be bright and eye-catching. The existing dot-matrix marks aren't. I have a few canned items in which the label is printed directly on the metal, but those are in the minority. I'm guessing it's a lot cheaper to print the complex full-color image onto paper and then attach that to the can.
-- wiml, Oct 14 2001


Yeah, paper can be printed flat by rollers extremely quickly and very cheaply...Cans don't survive this process well.
-- StarChaser, Oct 15 2001


Ultrasound is probably the best idea... the point [Rant93] brought up about the total density is true.

I've heard this turned into a bit of an obnoxious game bestowed upon the newly engaged/married before they live together. They each get a set of cans with the labels off, but marked with numbers, and their significant other gets the key... so they have to call each other (and often collaborate between sets) in order to make meals. Of course it's only funny if they don't cheat and give away the whole bit right off the bat.
-- Agamemnon, Apr 05 2006


I concluded after a quick test, that cans containing different things make a slightly different sound when you shake them. I don't know if that helps.
-- Zimmy, Apr 05 2006


Why not just use a roller type wheel in the factory to indent or raise bumps in morse code or braille on the lid or can side or even letters? Water won't wash these away.

(oasn)If I've gotten stranded with mostly tomato soup, I'd be happy for a good bit.(on a side note)
-- nth, Apr 05 2006


Similar to what [nth] said, when I was a child I asked my mother how we were going to identify our food if all the labels came off (one had fallen off). She then informed me that the horizontal ridges in the cans were different for each type of food, and you'd just have to know the pattern to identify the food.

Maybe this was actually true at some point in the past, at least within a particular company, but I'm pretty sure that it's not true now.

It would save a lot of time and bother, though, even if all you are identifying is that can that lost it's label that's sitting in the back of the cupboard unexpired.
-- drememynd, Aug 31 2007



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