How Julia Child's Chocolate Mousse Relies On Eggs Alone For A Fluffy Texture
There was no shortage of revolutionary recipes and cooking tips that came about when "Mastering the Art of French Cooking" was first published in 1961. Of course, of the three women who wrote the book, none became more iconic than Julia Child. She brought age-old cooking traditions to generations of admirers, and many of Julia Child's cooking tips are still in use. In one of her early episodes of "The French Chef" (seen here on YouTube), she showcased her chocolate mousse recipe from that first book, which featured a traditional French method of utilizing eggs.
In Julia's recipe, eggs are used to achieve the thick, yet fluffy texture of the chocolate mousse. What makes this recipe relatively uncommon for U.S. mousse-makers back then is that she uses both separated yolks and whites to achieve the mousse's texture. Common aerators for mousse include whipped cream, stiff egg whites, or pâte à bombe, which is egg yolks whisked with sugar. What Julia does is create a fusion of the latter two. The fat from the yolks thickens and stabilizes the mousse, while the aeration of the whipped whites provides the body and lightness.
This preparation of eggs is quite common in French cooking, however, as Julia points out in the episode. If you're going to try it, be careful with the egg yolks in particular, as they can curdle if you're not paying close enough attention. This all may sound incredibly technical, but in the hands of the master, it is downright simple.
How Julia makes mousse au chocolat
To start, Julia splits 4 eggs, separating the yolks and the whites. To the yolks, she adds ¾ cup of sugar and orange liqueur, and beats them all together until the mixture thickens. What happens here is the sugar draws out the water content of the yolks, which activates the fat proteins in the egg to thicken. The mixture gets whisked over a double boiler until it starts to become foamy and thickens to a mayonnaise consistency. This is the point where those yolks could curdle if they are overheated. The egg yolk mix is then added to some chocolate that has been melted in hot coffee.
The egg whites and a little bit of salt are whisked in a bowl until they begin to form soft peaks. This is what is going to make the mousse texture seem lighter than air. Fold the egg whites very gently into the chocolate mixture, then chill the mousse for at least 2 hours, or up to overnight if you can.
The result should be a densely chocolatey mousse that is also very light in texture. The fat from the egg yolks helps bring added richness to the chocolate, while the egg whites stabilize and maintain the shape of the mousse. You can serve the mousse in ramekins or even over a graham cracker crust to form a pie. Top with sweetened whipped cream or candied orange peel and you have yourself a wonderfully Julia dessert.