One of the benefits I've found from starting to use a "cozy" -- my favorite personal gear change of 2009 -- is that it holds my food warm enough that if I get feeling full -- just so full that i can't eat another bite -- I'll just zip the food back into the cozy and wait 10 minutes and come back and eat the rest of it. That's hard to do if your Mac-and-Cheese or rehydrated eggs have gotten all cold, not so hard if the cozy's kept the food warm. I used to bury leftover food (apologies to John Ditti and all other campers), but since adopting the cozy, I find I always can finish my meals.
The cozy arrangement that works for me is a 10-16 oz. specimen jar inside of a commercial cozy I got at REI.
The cozy was a Outdoor Products Insulated Water Bottle Holder which is lightweight, has a reflective liner, decent insulation value and is not too hard to clean if you spill food on it..
(I use the 1/2 liter size.)
Appropriately-sized specimen jars are harder to find but they are widely used in the biosciences. They tend to have very non-reactive insides, which makes them very easy to clean and wide mouths and straight sides.
They look like this:
I've gotten mine from friends, so I don't know where to buy them for sure. Here's one site that lists 8- and 16-oz. sizes.
The trick, of course, if finding (or designing) a cozy that fits the jar you want to use. I've got jars that are taller and thinner than the one illustrated above, so it works well in the OP insulated bottle holder.
This is probably obvious, but the idea is that I cook my food in a pot (JetBoil for me) up to the point when a little more steeping will get it fully hydrated, pour the food into the specimen jar and put it in the cozy to complete steeping. Then I just eat it directly from the specimen jar, still inside the (now unzipped) cozy. The specimen jar cleans just fine with a vigorous shake with water (no soap is required for most foods).
For 5-minute grains (like cream of wheat for breakfast), I find I can get it fully cooked with bringing to a bare simmer In the Jetboil, letting it steep in the Jetboil for about 5 minutes, re-bring it to a bare simmer (which takes minimal added fuel) and then pour into the specimen jar.cozy, let it steep 5 more minutes until it "gels" to a nice consistency and then eat. For meals based on 10-minute grains, I use one extra re-simmer and steep in the JetBoil before putting in the cozy. It allows me to avoid freeze-dried foods, which I'm not a fan of.
Since your food finishes cooking inside the specimen jar, rather than in the pot, it tends to be easy to wash the pot.
John Curran Ladd
1616 Castro Street
San Francisco, CA 94114-3707