text: A bain-marie ( also known as a water bath ) is a French term for a piece of equipment used in science , industry , and cooking to heat materials gently and gradually to fixed temperatures , or to keep materials warm over a period of time .
simplified: A bain-marie ( or water bath ) is a piece of equipment used in science , industry , and cooking to heat materials gently and gradually to fixed temperatures , or to keep materials warm over a period of time .