I recently wanted a way to cook stews and long cooking grains without heating my house up or having to babysit a pot on the stove. After reading about the Wonderbag, I figured I could make something to do the same thing from things found around my house. A wonderbag insulates a hot pot so it can continue cooking long after it is removed from the heat. So, I wrapped my cook pot in an old, felted wool bag, then a cotton towel, then two ponchos. I could have just as easily used a duvet cover, fleece blankets, or a sleeping bag. The only thing I would worry about is that that inner layers are a materials that do not scorch or burn. here is my bag wrapped up and held in place with a safety pin.
I made beef stew in it today, simmered it for 15 minutes, then wrapped it for 6 hours. It was still quite hot and completely cooked. It’s an ideal way to cook grains, beans, and any other foods that benefit from low, slow cooking. Small grains, like rice or quinoa only require the water to come up to boiling for a minute and an hour in the bag. I’ve not tried it, but if a ceramic pot is used, a microwave could be used to bring the meal up to temperature. This is great in places where energy is expensive, there is limited access to a stove, or a lack of time to tend a pot. It can also be a good way to transport a meal.