bainmarie

A bain-marie, also known as a water bath in culinary contexts, is a method of gentle heating that uses hot water to regulate temperature and protect heat-sensitive ingredients. The term is of French origin, literally meaning “bath Marie,” with the precise historical attribution unclear. The technique relies on surrounding the container holding the subject with a layer of hot water so heat is applied evenly and gradually.

In cooking, a bain-marie is typically made by placing a heatproof container—such as a metal or glass bowl—above a pot or pan of simmering water. This indirect heat is used to melt chocolate, butter, and other fats; to cook custards, curds, and delicate sauces; and to keep prepared foods warm without scorching. It is also employed in tempering chocolate and in some delicate dessert preparations where precise temperatures are important.

In laboratory and industrial settings, the term refers to a thermostatically controlled water bath designed to maintain a stable, moderate temperature for incubations, dissolving substances, or reactions that require gentle heating. These baths can offer precise temperature control, uniform heat distribution, and safe operation for sensitive samples.

Equipment commonly includes a sturdy outer vessel containing water, a smaller inner container for the material, and a means of controlling water temperature. Proper use requires maintaining an appropriate water level to ensure consistent heating and avoiding direct contact between the heating element and the contents.