A guide to modern cookery by A. Escoffier

2. It is quite an error to suppose that it is necessary to work over

ice or in a cold room. Cold is rather deleterious to the Mayonnaise, and is invariably the cause of this sauce turning in winter. In the cold season the oil should be slightly warmed, or, at least, kept at the temperature of the kitchen, though it is best to make it in a moderately warm place.