Water bath (bain-marie)

According to the Trésor de la langue française, a bain-marie is boiling water that heats substances in an immersed vessel gently and evenly; in the kitchen the name also covers a double vessel and the hot-water tank of a kitchen range. The German DWDS describes a pot of boiling water holding a smaller pot, so that food does not catch. Treccani instead gives water usually below boiling point; the sources differ here. The glossary of the 1907 English edition of Escoffier’s guide distinguishes two uses: keeping food in its containers warm, or poaching and cooking it in the bath.

Cooking in a water bath means the food actually sets or bakes there, as with eggs, custards or soufflés in a dish placed in an oven tin of hot water. Holding is for sauces and finished dishes that must neither catch nor cool. The name is recorded from 1516, and medieval Latin knew balneum Mariae. Tradition links it to the alchemist Maria the Jewess; both Treccani and the TLFi mention the legend that she was the sister of Moses.