A Bain‑Marie (from the French “bain de Marie”) is a kitchen device or setup used to gently heat, hold, or cook food via indirect, even heat. It’s very useful in commercial kitchens, buffets, catering, restaurants—anywhere you need to keep food hot (or cold) safely, without risk of burning, sticking, or losing moisture.The basic idea is a water bath: you have a larger container (well) filled with warm/hot water. Food pans (GN pans or sauce trays) sit in this water, so the food is heated gently by the surrounding water’s heat rather than direct flame or heating element. This gives more uniform temperature and avoids hot spots.
There are “wet” bain‑maries (with water) vs “dry” ones (no water, using heated plates/air) depending on how fast you want heat, how gentle you need it, and what food you’re holding. Dry ones heat faster but risk drying out delicate foods; wet ones are more forgiving.