The Name for this delicate dessert comes from a French word that translates literally as “frothy, foamy, or light.” To make a mousse, an aerator such as whipped cream or a meringue is folded into a base such as a fruit purée, vanilla sauce, cream or pudding, curd, sabayon, or pâte à bombe. The base should be light and smooth so the aerator can be incorporated easily. Stabilizers such as gelatin may be used in varying amounts, depending on the desired result. If a mousse is stabilized with gelatin, it will begin to set as it cools, so prepare all molds, serving containers, and so forth before beginning preparation.