A hot box is basically a type of cookware that consists of a large box filled with insulating materials. This is used by a cook first heating up food in a pot, typically with dishes such as stew or beans that are cooked for a fairly long time in a wet environment. The pot is then removed from a stove or other heat source and immediately placed into the insulation within the hot box. Once closed, the insulation traps the heat within the pot, allowing the food to continue cooking through residual heat.
There are a number of different ways in which a hot box can be made, though it is fairly simple and quite economic to construct. Just about any large box can be used as a starting point, though a cardboard box or large cooler are often the most popular choices. It is important that the box be large enough to fit insulating materials and the pot in which food is going to be cooked. Since the heat needs to be properly trapped within the hot box, it should also have a lid or otherwise be able to be closed in some way.
Different types of insulating material can be used within a hot box, often depending on what is available and what can fit within it. Straw or foam can work as insulation, though they typically need to be fairly dense to properly hold heat in and prevent it from escaping. Towels and rags can also be used, often wrapped around a cooking pot to keep the heat within. If a fairly large hot box is used, then a sleeping bag can also be an excellent choice, especially since they are made with insulation to keep sleepers warm in an outdoor environment.
A hot box functions by trapping in residual heat within a pot or other cookware. Food is placed inside a pot and this is heated using a stove or oven, in much the same way as if it is to be cooked. Before the dish finishes cooking, however, it is removed from the heat and immediately placed within the insulation of the box. Over time, the residual heat within the pot continues to cook the dish.
This type of cooking can require more time than a stove or oven, but it requires no additional power after the initial heating. Dishes like soups and stews can cook within a hot box over several hours, but only require heat and energy for one hour. Rice and beans can also be cooked in this way; they may take longer than stovetop cooking, but still result in tender and well-cooked dishes.