doubleboiler

A double boiler is a piece of cooking equipment consisting of two pots, one nested inside the other. The bottom pot holds a liquid, usually water, and the top pot holds the food to be heated. The heat from the liquid in the bottom pot gently heats the food in the top pot through steam. This indirect heat transfer prevents the food from scorching or burning, which can happen with direct heat from a stovetop.

Double boilers are commonly used for delicate tasks such as melting chocolate, making custards, sauces, and emulsifying ingredients like hollandaise sauce. The gentle, controlled heat ensures that sensitive ingredients cook evenly without overheating or separating.

The top pot of a double boiler is often referred to as a insert or bain-marie insert. The bottom pot can be any pot that fits the insert. Specialized double boilers are available as a single unit with integrated pots, but they can also be improvised using two pots of different sizes that fit together.

The principle behind the double boiler is similar to that of a bain-marie, which is a water bath used for slow and gentle cooking or keeping food warm. The steam generated from the simmering water in the bottom pot surrounds the sides and bottom of the upper pot, providing a consistent and mild temperature. This makes it ideal for recipes that require precise temperature control.