Chocolate Mousse

I’m not sure a universally beloved dessert exists. But if there was one, I’d be willing to bet it’d be chocolate mousse—chocolate pudding’s more grown-up, fancier cousin. It’s a timeless dessert, and one that continues to star on restaurant and dinner party menus. Rich with bittersweet chocolate and light as a cloud, each spoonful is a deeply pleasurable experience. Chocolate mousse is simple and elegant, and because it must be made ahead of time, it’s an ideal dessert for entertaining. Set it and forget it, then prep the rest of your dinner. You won’t have to return to it until the coffee and digestifs have been poured. 

There are numerous ways to make chocolate mousse. You’ve got avocado chocolate mousse, which gets its silky texture from ripe avocados whizzed together with cocoa powder and some kind of syrup (usually maple or agave) in a food processor. Molecular gastronomist Hervé This uses just two ingredients—bittersweet chocolate and water—and a little cooking science to create an incredibly creamy chocolate mousse that feels (and tastes!) a little too good to be true. And then there's the traditional French method of folding whipped cream, a meringue, and egg yolks into melted chocolate. I find the last of these to be the most delicious. 

If you’ve never made chocolate mousse before, the prospect of having to incorporate not one, but three different ingredients into melted chocolate can feel intimidating. There are several potential risks: What if the chocolate seizes? What if the egg whites deflate? What if it's not chocolatey enough? (No one's worried about it being too chocolatey, right? Right?) 

This recipe hopefully takes those worries out of the equation. Through rounds and rounds of testing, I've landed on a recipe that streamlines the process and improves chances of success. Here, I skip the whole folding-whipped-cream-into-chocolate thing, choosing instead to melt chocolate with heavy cream to help stabilize it and safeguard it from seizing. And with a little know-how, you won’t have to fear the egg whites deflating—just whisk them at a slower speed for a little longer to better stabilize them, then gently fold without worry.

I always joke that whatever you’re cooking can sense your fear. Don't give this chocolate mousse that pleasure. Approach the recipe with confidence, and you will end up with a spectacular mousse that would make a pastry chef proud.

The Best Chocolate for Chocolate Mousse

You’ve likely seen the percentages on chocolate, but what do the numbers actually mean? As Marissa Sertich Velie wrote for us in her guide to baking with chocolate, percentages tell you how much of the chocolate comes from actual cacao beans, like the chocolate liquor and cocoa butter. Chocolate liquor is what gives chocolate its signature flavor, while cocoa butter (the fat in cacao beans) carries little flavor and contributes mostly to the texture of chocolate. A 70% chocolate, for example, means that 70% of it is a mixture of chocolate liquor and cocoa butter, and the remaining 30% is sugar. The higher the percentage, the less sugar there is, making the chocolate a more bittersweet one.

The best chocolate mousses manage to straddle the line between a light and airy texture and a rich, dark chocolate flavor. The lightness comes from the whipped egg whites and cream, while the chocolatey flavor comes from, well, the chocolate. After arriving at a method and ratio of ingredients that achieved the right light and airy texture, I tried the recipe with four different chocolates: milk chocolate (40%), semisweet (46%), and dark chocolate (64% and 70%). Both the milk chocolate and semisweet proved a little too sweet, and though I enjoyed the mousse made with 64% chocolate, I found that using 70% chocolate resulted in a more balanced and complex tasting mousse with bittersweet notes. 

Since chocolate is the star of this dessert, I recommend going out of your way to buy truly excellent chocolate. My preferred chocolate is Valrhona Guanaja 70% (which I order online because it isn’t readily available in grocery stores) but Guittard’s 70% baking bars are also a great option.

Stabilizing Your Chocolate

One of the pitfalls of melting chocolate is having it seize on you: that unfortunate moment when the velvety-smooth chocolate you’ve just melted becomes sandy and too stiff to work with. “The tiniest bit of moisture, even steam, can cause flowing, shiny melted chocolate to become a solid, dull, grainy mass,” writes Shirley Corriher in her 2008 book BakeWise. With chocolate mousse that’s made the traditional way, where you incorporate both whipped cream and a meringue, seizing usually happens when you’re introducing those ingredients too quickly or at the wrong temperature. 

The solution is counterintuitive. Rather than steer clear of liquid, we want to add more—just enough!—to coat the cocoa particles and keep them fluid. The higher the percentage of chocolate, the higher the amount of cocoa, and the more liquid you’ll need to add in order to prevent seizing. While semisweet chocolates (55 to 60%) require just 15ml of liquid per 2 ounces of chocolate, dark chocolates (60 to 70%) need at least 22ml per 2 ounces of chocolate. 

How you introduce that liquid is key. “The fail-safe way to combine chocolate with other recipe ingredients,” Corriher advises, “is to melt the chocolate with any liquid or butter in the recipe.” Her chocolate mousse recipe is simple, and involves just melting chocolate, sugar, and cream together, then allowing it to chill overnight before whipping it to firm peaks. Taking a page out of Corriher’s book, I decided not to whip my heavy cream. Instead, I placed the heavy cream in a bowl with chocolate set over a simmering pot of water to melt together. This not only stabilizes the chocolate and prevents it from seizing, but also lightens up the mixture, making it easier to fold together with the whipped egg whites without deflating the mousse. Though this recipe lacks the whipped cream you see in traditional methods, the mousse gets enough aeration from the egg whites alone and is equally light in texture.

The Key to Light, Airy Mousse: Making a Proper Meringue

A sturdy, well-whipped meringue is essential for a light, silky mousse. If you’ve ever had a dense meringue-based chocolate mousse, it’s likely that the egg whites deflated during the folding process. The idea of having to keep your meringue intact while incorporating it into your chocolate mixture might be daunting, but there are ways to safeguard your meringue and prevent it from collapsing, namely—stabilizing it. 

It may seem logical to turn up the speed of your mixer when beating egg whites—faster beaters equals more air, right?—it's actually the opposite that's true. For a more stable foam that’s less likely to deflate, you need to beat it at a slower speed for longer. (I’m not talking about turtle-speed-slow—medium speed on a stand mixer is just fine.) In his book Kitchen Mysteries, French gastronomist Hervé This explains that the air bubbles in egg whites are large when we begin whipping them, but become smaller and more stable the longer we whisk—the result of proteins unfolding and connecting with one another to form a network around the bubbles. By setting the mixer to a medium speed, we give ample time to form this finer foam structure, which is more stable than one full of larger bubbles. Adding a touch of acid like cream of tartar also helps to strengthen and coagulate egg white proteins. Still, according to This, it’s more important to whip your whites well.

Once your egg whites reach stiff peaks, you’ll want to use a silicone spatula to gently incorporate it into the mixture of melted chocolate and cream, working upwards along the curve of the bowl to fold the bottom over the top. Start by incorporating a quarter of the meringue to lighten up the chocolate, then fold in the rest, rotating the bowl as you go. There’s no rushing this! Be patient and work slowly and thoroughly to ensure the meringue and chocolate are thoroughly combined, lest you’d like streaks of egg white through your mousse.