2-ingredient Chocolate Mousse by Hervé This

In his book Molecular Gastronomy: Exploring the Science of Flavour (Columbia University Press, 2008), French chemist Hervé This detailed how make creamy dairy-free chocolate mousse with just 2 ingredients: high-quality couverture chocolate and water.

While traditional mousses require egg yolks or heavy cream to develop their rich, velvety texture, This’s version relies on a trick of science. He combines two seemingly disparate ingredients—chocolate and water—to create a mousse of astonishingly airy and silky texture.

Hervé This figured out that couverture chocolate doesn’t need the fat from the cream or the lecithin from the eggs to become a mousse. High-quality couverture chocolate already contains fat in the form of cocoa butter, as well as lecithin (which is commonly used as an emulsification agent to bind cocoa solids, cocoa butter, and sugar during the manufacturing process). So in this recipe, all that is needed in order to create a mousse is liquid and whisking. Amazing!



  1. Prepare an ice bath: fill a large bowl with ice and water. Set aside.

  2. Heat 3/4 c water (or other liquid*) in a small saucepan. Heat until gently boiling; add the chopped chocolate. Remove from heat and whisk until melted. Stir until the chocolate is completely melted and the water and chocolate are combined. 

  3. Place the saucepan in the ice bath (if your saucepan is too large to fit the ice bath, you can transfer the chocolate mixture into a separate small bowl).

  4. While resting in the ice bath, whisk the chocolate sauce (use a hand whisk or an electric mixer. If using an electric mixer, watch closely—it will thicken quickly). Whisk until it resembles lightly-whipped cream**, about 2 minutes. Whisking creates large air bubbles in the mixture, which causes it to steadily thicken.

  5. Pour or spoon immediately into 4 ramekins, small bowls, or jars and let set. 

  6. If you'd like, top with whipped cream, toasted nuts, fresh or dried fruits.

  7. Serve immediately. This chocolate mousse is best enjoyed right away—refrigerating it makes it lose its fluffy texture.

  8. Serves 4.

* Flavour variations: 

Instead of water, use the same amount of another liquid. For example: tea, coffee, orange juice, passion fruit juice, rum, whisky, Kahlúa, or cherry liqueur. You can even add spices, like cinnamon, or a bit of sugar if you'd like it sweeter.

** Trouble shooting: 

If the mixture is very thick and grainy-looking, that means you have over whipped. Don't worry, it's not ruined! You can re-melt the mixture in a microwave-safe bowl in the microwave in 10-second intervals until smooth and try again. The remelted mixture will not completely deflate. Whisk gently until slightly thickened but still slightly looser than the first attempt, 30 seconds to 1 minute.

Recipe courtesy Hervé This, Molecular Gastronomy: Exploring the Science of Flavour (Columbia University Press, 2008).


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