Chocolate mousse is a quintessentially French dessert that turns rich, thick chocolate into light-as-air foam — which makes sense since "mousse" is French for "foam." The foam is created by gently folding whipped egg whites and cream into melted chocolate, and as it cools, all of those bubbles are locked into place.

Most recipes for chocolate mousse call for dark chocolate, because milk chocolate and semi-sweet chocolate fade into the background of the mousse. Dark chocolate contains less sugar and a lot more cocoa solids, which mellow into the perfect choice for a mousse.

Dark chocolate has a wide range identified by the percentage on the package, from 50%-90% cocoa solids (the remainder being cocoa butter, sugar, and possibly some dairy). For a mousse, around 70% is the best option, because it contains enough concentrated chocolate flavor, but not so much that it turns your mousse bitter.