Rustic chocolate mousse, popular for decades, is still on Parisian menus
On a trip to Paris last month, I ate Chocolate Mousse many times in restaurants and cafes, where it’s been on menus for decades and never gone out of style. It was pretty wonderful every time and I wanted to make it as soon as I was in my own kitchen. I found my favorite recipe and knew I couldn't prepare it because raw egg yolks are beaten into the chocolate; that’s no longer considered safe. Because there’s a chance that raw eggs contain salmonella, the US Food and Drug Administration recommends that all eggs reach 160 degrees before consuming. That pretty much eliminates most classic recipes, including mine.
British celebrity chef Heston Blumenthal makes a recipe for mousse called Chocolate Chantilly, developed by Herve This, a founder of Molecular Gastronomy, which contains only chocolate and water. To make it, Blumenthal melts the chocolate in the liquid, then whisks the mixture over ice until it is the consistency of heavy cream. It seems simple, but it's not. If you let it go a few seconds too long, you lose the mixture.
There are ways to get the yolks up to temperature for chocolate mousse. I decided to begin by making Vanilla Custard Sauce (also known as Creme Anglaise), not for the novice. You stir egg yolks, sugar, and a little milk in a bowl. Heat the rest of the milk in a saucepan. When it is scalded, gradually pour the hot milk into the yolk mixture, then return it all to the saucepan and stir constantly and patiently until it thickens. The tricky part is that the sauce can boil, which means it curdles. So set a fine-mesh strainer over a bowl and as soon as the sauce thickens, pour it into the bowl. Then stir strong liquid black coffee or espresso into the sauce, with melted bittersweet or semisweet chocolate. When I make it this way, the melted chocolate mixes nicely with the custard sauce and forms minuscule specks of set chocolate in the mousse. Yes, you could strain these out, but they give the mousse a more rustic texture, which I like. Two important things: You must use top-quality chocolate for this because it’s the main ingredient. Read the recipe carefully before you start so you have all the equipment you need on hand (a heavy-based saucepan, two heatproof rubber spatulas, and more). Working with chocolate is tricky, and messy, but then you sit down with a lovely little cup of chocolate mousse and decide it’s worth it.
Rustic chocolate mousse
Serves 4
6 ounces top-quality bittersweet or semisweet chocolate, coarsely chopped
4 egg yolks ‚ cup sugar, or more if needed
1½ cups whole milk
1 teaspoon vanilla extract
½ cup strong liquid black coffee or espresso
1. Have on hand 4 custard cups or glasses (1 cup capacity each).
2. In a heavy-based saucepan, bring 2 inches of water to a boil. Set the chocolate in a heatproof bowl over hot, but not boiling, water. Stir with a heatproof rubber spatula until the chocolate melts completely.
3. Remove the bowl from the saucepan. Use a paper towel to wipe the bottom of the bowl dry. Wipe out the saucepan.
4. In another bowl, whisk the egg yolks and ‚ cup sugar to blend them thoroughly. Whisk in ½ cup of the milk.
5. Have a bowl with a fine-mesh strainer near the stovetop.
6. In the saucepan, heat the remaining 1 cup milk until you see tiny bubbles at the edges. Remove the pan from the heat. Very slowly, stir the hot milk into the egg mixture. Then pour the entire egg mixture back into the saucepan.
7. Over medium-low heat, using a clean heatproof rubber spatula, stir the milk mixture constantly until the custard thickens slightly. Watch it carefully and do not leave the burner or stop stirring. The custard is ready when you remove the spatula from the mixture and draw your finger along it; the line you drew will stay clear. Do not let the mixture boil or it will curdle.
8. Immediately tip the custard mixture into the strainer. Do not press the contents of the strainer into the custard.
9. Stir the vanilla into the hot custard, followed by the coffee and chocolate. Stir until the mixture is thoroughly blended. Taste the mixture for sweetness. Add more sugar, 1 teaspoon at a time, if you want a sweeter mousse. (Bittersweet chocolate may need more sugar than semisweet chocolate.)
10. To divide the mixture neatly among the cups, use a spoon or small ladle. Or transfer the mixture to a large measuring cup and pour it into the cups. You may get drips down the sides of the cups. Wipe the outside drips with a damp paper towel; leave the inside drips.
11. Set the cups on a rimmed tray or plate. Cover loosely with plastic wrap. Refrigerate for at least 4 hours or for as long as 3 days. Serve plain or with a sugar cookie.