I will always remember the first time I tasted mousse au chocolat. I remember that it was in France. I remember that I had lunch on my own and the direction I was facing in the restaurant was toward the front windows. But I don’t remember either where in France it was or the name of the restaurant. All I remember is that it was the best chocolate I had ever tasted and that I was so spellbound I had to ask the waitress for the secret to its flavor. Her answer: Madame c’est le chocolat!
It seems obvious now, but in those days in the USA people used “baking” chocolate and not fine eating chocolate for desserts. So on my return home, I went to the lower east side to Essex Street Candy and purchased the best chocolate I knew of which was Lindt. The owner asked me what I was planning to use it for and when I said baking, he firmly informed me that it was “eating” chocolate. But you eat what you bake was my reply. Coincidentally, David Liederman had just put his chocolate chip cookies on the culinary map, in New York City, using the exact same chocolate cut into small pieces instead of chips. There was no going back.
Recently I had a sudden craving for chocolate mousse and a desire to create the best one to suit my current taste and texture preferences. My goal was a mousse that would be silky-creamy and slightly airy, chocolaty but not overly intense and more on the bittersweet than milk chocolate spectrum. Valrhona le Noir Gastronomie (aka bittersweet) 61% cacao was my chocolate of choice, and of course there is always egg yolk and a little sugar to balance what would be either butter or heavy cream or sometimes both. My favorite chocolate mousse for years was one I created for Poulain chocolate, which used only heavy cream and optional Kahlua or Cognac but it was high in egg white and I now found it too airy. Julia’s classic version uses both butter and heavy cream, and liqueur.
Both coffee and liqueur heighten the taste of chocolate, but this time I wanted only the pure taste of the best chocolate and maybe a touch of vanilla. I was undecided about the butter. I wanted the mousse to be fairly light and—well—moussey, and from my years of baking experience I’ve found that the more an ingredient is processed the more the flavor changes (i.e. butter starts off as cream and cream has a floral quality mostly lost in butter). I decided to consult my two favorite chocolate friends: Zach Townsend, chocolatier in Texas, and Lisa Yockelson (author of Chocolate Chocolate). They both, eloquently and precisely, put into words exactly what I was perceiving.
Zach: With butter it's more pudding-ish. I like creamy and airy.
Lisa: If you want an intense chocolate dessert, prepare a pot de crème or a pan of brownies. I agree with you that the most luxurious chocolate mousse is enriched with whipped heavy cream, and that butter seems to make the finished sweet too dense and a bit slick. As well, butter does not convey the same luscious dairy quality to the mixture and, if you use a high-quality bittersweet chocolate, the cacao flavor will not be diluted when using cream
So I chose a higher than usual proportion of cream to chocolate and a larger than usual amount of egg yolks. Heating the yolks with the chocolate and cream and then straining the mixture before folding in the stiffly beaten egg whites (see Notes), produced the silky texture of my dreams.
Prep Ahead: Make the mousse 1 day up to 3 days before serving.
Equipment: 6 half ramekins (2/3 cup/158 ml capacity)
Makes: about 3.25 cups/775 ml/6 servings
Mise en Place
* Separate the eggs, placing the yolks in a medium bowl and the one egg white in a mixing bowl. Lightly whisk the yolks and leave the whisk in place.
* Chop the chocolate into small pieces and set it in a small saucepan.
Have a fine strainer ready near the range, suspended over a medium mixing bowl.
1) Add the cream to the chocolate, and heat on low heat, stirring constantly, until the chocolate has melted and the mixture is hot (about 120˚F/49˚C).
2) Whisk a few tablespoons of the hot chocolate mixture into the yolks. Then add the yolk mixture back into the chocolate mixture in the pan, stirring constantly.
3) Continue stirring on very low heat, just until it starts to thicken. An instant-read thermometer should register 160˚F/82˚C.
4) Immediately remove the pan from the heat and pour the mixture into the strainer, scraping up the thickened cream that settles on the bottom of the pan. Press it through the strainer and scrape any mixture from the bottom of the strainer. Stir in the vanilla.
5) Press a piece of plastic wrap directly on the surface to keep a skin from forming. Set the bowl on a rack and allow the mixture to cool to room temperature (about 1-1/2 hours).
6) In a medium bowl, beat the egg white and cream of tartar on medium-low speed until foamy. Gradually raise the speed to medium-high and beat until soft peaks form when the beater is raised. Gradually beat in the sugar until glossy curved peaks form when the beater is raised. Use a whisk to fold the meringue into the chocolate mixture. Finish with a large silicone spatula, reaching to the bottom of the bowl. Spoon the mixture into the ramekins.
7) Cover each ramekin tightly with plastic wrap, stretching it across to keep it from touching the smooth surface of the mousse. Refrigerate for a minimum of 8 hours up to 3 days.
Sugar is a personal taste and more can be added if you prefer less bittersweet.
Using the proper amount of cream of tartar makes it possible to beat the egg white to stiff consistency without breaking them down.
For the immune impaired, the very young, or the very old, I recommend using pasteurized eggs such as Safest Choice. You will need to use double the cream of tartar and beat longer for the egg white but they produce an extra stable meringue.
If your cooktop does not have a very low heat setting, it's best to use a double boiler.
To make Pot de Crème, which is a more intense and denser chocolate dessert, omit the egg white (and cream of tartar) and use only 2-1/2 to 3 egg yolks (45 grams).