A double boiler is a type of cookware that uses steam as a heat source to melt or cook food. It is made up of two pieces, a large pot that is filled with hot or boiling water and a smaller pot that fits inside to trap the steam from below. The heat comes from an indirect source, making double boilers ideal for cooking delicate foods like sauces and types of chocolates. Double boilers may also be called bain maries, which is the French term for the method of cooking with indirect heat from steam. The key features of a double boiler are:

• Gentle Heat: Double boilers create gentle, indirect heat, which is ideal for melting and tempering.

• Temperature Control: The water in the bottom pot of a double boiler can only reach 100°C (212°F) before it boils, which limits the maximum temperature the food being cooked can reach.

• Steady Heat: The double boiler maintains a steady, even temperature due to being heated by the surrounding liquid. This makes it a good environment for temperamental foods/sauces that require a very specific temperature.

A double boiler is used for cooking delicate ingredients that have a tendency to seize or separate over direct heat, as when tempering chocolate, whisking up an egg-based sabayon, or keeping gravy warm. It is also used for heating egg whites and sugar for a meringue that will hold stiff peaks, or for a hollandaise sauce where you could break the precarious emulsion if the egg yolks overheat. Double boilers are ideal for melting and tempering chocolate, making delicate sauces like hollandaise, and cooking any sauce that is too delicate for direct heat. If you dont have a double boiler, you can make one by setting a tempered glass or stainless steel mixing bowl over a saucepan of simmering water.