Guinness Chocolate Mousse Recipe

Chocolate lovers are fortunate in that chocolate, which is perfect enough on its own, can taste even richer and more decadent when paired with certain ingredients. One you may already know about is coffee. Another, as it turns out, is Guinness Extra Stout. With this recipe for Guinness chocolate mousse from recipe developer Jennine Bryant of The Marshside Pantry, you can try the tasty combo yourself.

"Adding the Guinness to the mousse gives an extra depth to the chocolate flavor," Bryant tells Mashed. "The flavors pair really well ... it also adds a great, Irish twist for St. Patrick's day." And something else it adds that is very important to mousse? Tiny little air bubbles in the form of carbonation. Mousse gets its "light foamy texture," as Bryant puts it, "[by] incorporating air bubbles into the mixture. This is done by either folding in whipped cream, egg whites, or both." This recipe uses both ... plus the Guinness. It also uses white chocolate in a layer of white chocolate mousse that, as you can see from the photo above, gives this clever appearance of a pint of Guinness. Ready for some airy chocolate fun? 

To make Bryant's recipe for Guinness chocolate mousse, you'll need ⅓ cup of Guinness (don't feel bad about drinking the rest of the bottle while you prepare the mousse), 4 ounces of chopped dark chocolate, ¼ cup of unsalted butter, and 1 large egg at room temperature, which you'll need to separate into the white and the yolk. You will also need 1 cup of whipping cream, divided, 2 tablespoons of sugar, and 3 ounces of chopped white chocolate.

A ganache is a smooth, supple filling or frosting made from chocolate and cream. Its relative hardness or softness is a function of the particular recipe's ratio of chocolate to cream (or, in this case, butter, which is the solid form of cream). This particular recipe starts by creating a ganache of 4 ounces dark chocolate and 2 ounces butter by melting them together in a heatproof bowl in the microwave. The 2:1 chocolate ratio is "just right" for creating a flavor base for mousse or another whipped filling. One pro tip from Bryant is to set the temperature of your microwave to low and check the chocolate and stir the mix every 20 seconds. This will help prevent scalding.

It shouldn't take more than a minute to melt the chocolate and butter into a ganache. Then, stir the ganache until it's smooth and shiny, which should take no more than a few seconds. Pour in the Guinness, and whisk to combine everything. Add the room temperature egg yolk and whisk the mixture again — just to combine fully until smooth. 

Leave the mixture to cool completely. While you wait for the mixture to cool, take a medium-sized bowl and place it in the refrigerator to make it nice and cold. Then, turn to the next step.

The way this wonderfully smooth chocolate Guinness mixture transforms into mousse is via the addition of freshly whipped cream. While you're waiting for the chocolate mixture to cool to room temperature, use your chilled bowl (from the previous step) to whip up half the cream (½ cup). Use an electric beater set to high for this. Keep mixing until your whipped cream forms stiff peaks. Set this whipped cream aside in the refrigerator, covered lightly with plastic wrap.

Has your Guinness and chocolate mixture cooled to room temperature yet? If so, then it's time to gently fold in the whipped cream that you just made. You'll want to do so ever-so-gently to preserve the air that you've whipped into the cream. This is what will turn your smooth Guinness-flavored chocolate into the creamy, mouthwatering mousse you're making. But we still have a couple more steps to go before it'll be ready to serve.

Grab another clean, medium-sized bowl, and use an electric mixer to beat the egg white until it's foamy and stiff. Then, slowly add the 2 tablespoons of sugar, 1 at a time, until the sugar is completely mixed in. The mixture shouldn't feel grainy between your fingers. If it does, keep beating the mixture until it feels smooth. Gently fold the egg white into the chocolate mixture. Grab 4 dessert glasses, and carefully divide the mixture between the 4, and place them in the fridge to chill while you make the white chocolate ganache.

For the final flourish, we're going to make another ganache, this time with the white chocolate and ¼ cup whipping cream. Melt these 2 ingredients slowly in the microwave, checking regularly, just as you did with the dark chocolate. Once the white chocolate has completely melted, give the mixture a stir to combine well, and set it aside for 15 minutes until it has cooled and thickened. 

In the meantime, use your electric mixer to whip up the final ¼ cup cream. Fold it into the cooled white chocolate mixture, and spoon it on top of the chilled chocolate mousse. Serve the mousse as is — a sweet replica of a pint of Guinness — or you can add a flourish. Bryant melted a little dark chocolate and drizzled it into the shape of a shamrock, giving it time to harden before dropping it right on top of the dessert's white chocolate "head."