Last Christmas, my daughter made me a Wonder Oven, a type of thermal box. She found the directions online. It is basically a pillow, much like a bean bag chair. It has two parts – a top and a bottom. A pot fits into the middle of the bottom section, and the top covers the pot. The Wonder Oven keeps food hot for several hours, and in fact will actually cook or continue to cook food while it is keeping the food hot. Basically, you heat up the food to a cooking temperature, put it into the Wonder Oven and let it sit for several hours. Wonder Ovens are not new. The concept has been around for a long time. And there are several websites devoted to wonder ovens, hay boxes, and other types of thermal boxes, with detailed instructions for making and using them. Thermal boxes don’t have to be fancy and can be made from all kinds of materials including blankets, hay, newspapers, fur, wool, etc. Mine is filled with little pellets and I usually use it to keep the food warm until dinner time after I have taken it out of the solar oven. It is a perfect complement to my solar oven.
Have you ever used a Wonder Oven, a haybox, or other thermal cooker? How did it work out for you?