The idea behind a hot water bath is to provide heat for cooking various foods, while lowering the chance for the food to scald or burn. This is accomplished by preparing a bath of hot water, placing the food in a cooking dish, and placing the dish in the hot water. Perhaps the most common example of this method of cooking is the double boiler.
A double boiler includes a pot on the bottom that is filled with water. A second pot fits on top and serves as the container for the food. As the water boils in the bottom chamber, heat is generated that rises into the top chamber and slowly heats and cooks the food. Pie fillings, home made chocolate pudding, various forms of egg custards, and delicate sauces are just a few of the dishes that are prepared using the double boiler. Since each of these recipes call for ingredients that could easily scald or burn if direct heat were applied, the indirect heat that is generated with this method is a better way to cook them.
Of course, it is possible to employ a hot water bath even if a double boiler is not available. For example, combining a stainless steel Dutch oven with an aluminum or stainless steel mixing bowl that is roughly half the size of the Dutch oven will work very well. A cook can simply fill the Dutch oven about half full of water and bring it to a boil. The mixing bowl is them placed into the boiling water, with the cook making sure that the water will not rise over the lip of the bowl. From there, it is an easy task to prepare the custard, pudding, or sauce in the bowl without having to be concerned about burning the mixture during the cooking process.
Cooking over hot water is not a new process, and the technique has been around so long that no one is exactly sure when it first made an appearance. While some people tend to think that using a hot water bath has to be a complicated process or that special pots are needed, the fact is that most kitchens already contain everything required to cook in this fashion. As a means of preparing foods that are subject to burning easily, it is an excellent option.