How to Make the Lightest Chocolate Mousse

I’m in no mood to bake. I returned from vacation this week and was greeted with unwelcome news: high temperatures and a very particular New York-New Jersey humidity. The idea of preheating the oven is laughable until this heat wave breaks, so I’ve turned to the refrigerator for my “baking.” The immediate response is, why not the freezer? Without the right machinery, frozen desserts (ice creams or sorbets) end up gritty, icy, or otherwise subpar. Fridge-chilled desserts, however, give you the perfect texture with little effort, and usually require pretty average kitchen equipment. Our Ultra-Light Chocolate Mousse is the perfect example. It’s low-effort, flavorful, surprisingly light and, crucially, needs no oven.

Egg whites vs. heavy cream

At its core, any chocolate mousse consists of a chocolate-egg yolk base and a whipped component. That whipped component is what makes mousse mousse-y. It’s where all the aeration and silkiness occurs, and it’s the component that can make or break the chocolatey flavor. Usually, this important job falls entirely on whipped cream or a combination of whipped cream and whipped egg whites. In our mousse, however, we lean entirely on egg whites.

Whipped cream is less intimidating than using raw whipped egg whites in a mousse—but it’s not the move. Cream, and other high-fat dairy, has a muting effect on chocolate. We use bittersweet chocolate for a balance of earthy tannins and sweetness, but this complexity is dulled against whipped cream. Cream contains a 36% to 40% milk fat, and that saturated fat has a coating effect on your palate, as well as a heaviness that fills you up after a few bites. Egg whites are fat-free, whip into small, stable and silky bubbles, and they don’t bring in competing flavors. This makes a difference that is obvious as soon as you run a spoon through the dish. The richness from the chocolate is front and center, and yet the texture doesn’t suffer from sticky density often present in other mousse recipes.

Don’t break a sweat

This recipe only requires enough heat to warm the half-and-half and melt the butter. While our recipe indicates using a saucepan on the stovetop for this step, you can avoid the stove altogether and do it in the microwave. The hot liquid is poured over the chocolate to melt it down—and that’s pretty much the hard part, done. Thankfully, because I had nearly no energy left. (My home has no air conditioning.)

From here, you’ll whisk a couple egg yolks into the cooled chocolate mixture. The yolks lend richness and body to the mixture while also serving as an emulsifier. A heap of egg whites get whipped (in a stand mixer, save your strength) with brown sugar, sweetening the mix and filling out the flavor profile with complementary molasses notes. The egg whites get folded into the base and the mousse is poured into a serving dish to cool in the fridge.

The hands-on portion takes a grand total of about 20 minutes, and the rest of the wait is fridge time. It’s a good idea to whip-up this dessert earlier in the day so when you’re half-melted and ready for a cool snack, you can hide out in the fridge for a chocolate mousse break.

More of our favorite desserts to cool down with:

• Cherry and Chocolate Crumble Semifreddo
• Mascarpone Mousse (Crema al Mascarpone)
• Strawberry and Amaretti Fool

Baking Tip of the Week: Fold for success

“Folding” is a technique you’ve seen in recipes from cake batters to puddings and soufflés. It’s a gentle stirring method to incorporate different ingredients while preserving air bubbles from a whipped component. It’s one of those pastry moves that is both vital to get right, and also not that serious. That’s to say, there are a couple things that actually matter, and the rest is just mixing.

Don’t overwhip. When folding is on the horizon, you don’t want to whip to the stiff peak stage. Stiff peak egg whites are resistant to blending into bases. They tend to hang on together in clumps, and while you can bust them apart, but will end up knocking the air out in the process. Stop at medium-firm peaks (when you lift the beater, the peak hold shape but gently flop over like soft-serve ice cream) which have structure but blend easily into other mixtures.

Sacrifice the first addition. You’ll fold the egg whites into the base in three or four additions. The first addition is an unceremonious moment. Don’t stress here, add a quarter or a third of the whites and stir it in. Its function is to lighten the base and no matter how you stir it in, you will succeed. With each subsequent addition, fold more gently.

Don’t leave any clumps or streaks. Unlike with flour in pancakes of muffins, if you leave a lump, blob or streak of egg white in this mixture, it’s not getting absorbed or disappearing in the end. As much as you want to be gentle and preserve air bubbles, you must also be thorough. You don’t want to dive into the mousse later and get a scoop of plain egg white. Poke through your mousse and gently smear and stir away any white clumps you come across. The mousse should be a homogeneous chocolate color and have a smooth texture.

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Allie Chanthorn Reinmann

Allie Chantorn Reinmann is a Digital Staff Writer for Christopher Kimball’s Milk Street. She’s a Thai-American chef who earned her diploma for Pastry and Baking Arts at The Institute of Culinary Education and worked professionally for over a decade honing her craft in New York City at places like Balthazar, Bien Cuit, The Chocolate Room, Billy’s Bakery and Whole Foods. Allie took her know-how from the kitchen to the internet, writing about food full-time at Lifehacker for three years and starting her own YouTube channel, ThaiNYbites. You can find her whipping up baked goods for cafés around Brooklyn, building wedding cakes and trying her hand (feet?) at marathon running. She’s working on her debut cookbook and lives in Brooklyn, NY.