Adan, and others...
I cook the Korr dishes in the foil bag in which they are packaged. There is no freezer bag in this style.
I insert the Korr Side in a cozy and pour the boiling water into it, although I sometimes will only have the bag halfway into the bag while the water goes in.
When I used just a single cozy made from Insul Brite, I found that I could cook a 7 or 8 minute Korr Side dish nicely in a cozy but I had to allow it to sit in for something like 11 to 15 minutes. I also had to use less water.
The reason for less water is that the 7 or 8 minute stovetop simmer in the recipe on the package involved simmering loss of nearly 1/2 cup of water. When the package and cozy are closed up, there is no such water loss and as a result, if you used the full recipe amount (roughly 2 cups of liquid) you would get a wet soupy product.
Cooking is a thermally activated kinetic process. So, if the water temperature is reduced, it takes longer to cook.
In the cozy method of cooking, the boiling water cools somewhat from heating up the room temperature ingredients in the Korr Side bag. So, the cooking time must be extended to account for this.
In addition, the Cozy temperature is dropping because the cozy isn't a perfect insulator, and some heat diffuses through the cozy. So, it cools. And this too means that you have to add more cooking time in order for the (partly) cooked initial ingredients (mostly rice or pasta)to finish cooking.
If you use just a single cozy of the Insul Brite kind, it is nearly hopeless to try to cook a 12 minute Korr Side product because the time and temperature needed are almost not obtainable in a cozy because the heat leaks out with time, and you eventually reach a point where virtually no cooking is going on because the water temperature had dropped too much in the cozy.
By doubling the cozy thickness by nesting two of them, theory has it that you should be able to cook a 10 or 12 minute Korr Side dish by reducing the amount of water even more than for the 7 or 8 minute dishes (because the package recipe includes the amount of water that will simmer away in 10 or 12 minutes). Of course, the temperature still drops on heating up the room temperature ingredients and the temperature still drops from thermal conduction through the cozy, so you will have to use more cozy time for cooking than the stovetop time on the package.
I didn't repeat the experiment on 10 and 12 minute dishes, so other than the time I listed initially, I have no new information to give.
1) Too much water = soupy final dish
2) Not enough "cozy time" = undercooked with crunchies.
3) Poor insulation for a long cook dish = not a good dinner.
If you do freezer bag cooking, following the good Sarah, and use instant rice (which is precooked and subsequently dehydrated) or use cooked pasta and dehydrate it-- then the "cozy time" is way down to 5 or 10 minutes. Just follow her instructions in her excellent book and website. A single cozy is more than adequate for doing the style advocated by Sarah.
I often add foil packed meat (salmon, tuna, chicken, bacon, ham, dried beef,...)to the Korr package, and sometimes add dehydrated vegetables. Some of the commercial vegetables were dehydrated raw, and those kind of green beans will be a little "stringy" as they didn't fully cook in the time and temperatures inside the cozy.
If I dehydrate green beans, I buy frozen beans and microwave the whole bag according to instructions and then dehydrate the cooked product. Adding these to a Koor dish perks it up quite a bit.
I was primarily interested in finding out how to "cozy cook" those long cook Korr dishes that require 10 to 12 minutes of stovetop simmering. I have decided that there are so many great 7 and 8 minute Korr dishes available, that the gains from extra efficient cozies to fully cook these dishes isn't any longer a high priority for me. I can do it, but do I really need that particular variety in meal selection?