Mousse au Chocolat
Ingredients
- 170 g bittersweet or semisweet chocolate, chopped
- 170 g unsalted butter, cut into pieces
- 60 ml strong brewed coffee
- 4 large eggs, separated
- 130 g sugar, plus 1 tbsp for the whites
- 30 ml dark rum
- 15 ml water
- Pinch of salt
- ½ tsp vanilla extract
This is the mousse from Mastering the Art of French Cooking, the version that fixed the French bistro standard in the English-speaking kitchen. It has no cream in it at all: the body comes from chocolate melted with an equal weight of butter and a little strong coffee, folded into egg yolks whipped over heat with sugar and rum until they hold like runny mayonnaise, then lightened with meringue. Whipping the yolks warm and then cooling them over ice is what gives the finished mousse its dense, slightly sticky texture rather than an airy foam.
Method
Melt the chocolate, butter and coffee together in a bowl set over simmering water until smooth, then take it off and let it cool to tepid.
Fill a large bowl with ice water and set it aside.
In another bowl over simmering water, whisk the egg yolks with the 130 g sugar, the rum and the water for about 3 minutes, until thick like runny mayonnaise.
Set that bowl in the ice bath and beat gently until the mixture is cool and thick, then fold in the chocolate mixture.
Beat the egg whites with the salt until frothy, add the remaining tablespoon of sugar and beat until thick and shiny but not stiff. Beat in the vanilla.
Fold a third of the whites into the chocolate to loosen it, then fold in the rest gently.
Spoon into serving dishes and refrigerate at least 4 hours, until firm. It keeps up to 4 days.
