Going Old School
French chocolate mousse, the kind made with raw eggs, has been around forever because people can't seem to get enough of its impossible lightness and unbelievable chocolate satisfaction. Click through to learn tips and tricks for making amazing French chocolate mousse.
When making something as simple as chocolate mousse, you should use the best ingredients you can find. The chocolate flavor and texture is important, so splurge on a good brand, around 70% cacao. Also, because the eggs in this classic French preparation are raw, sourcing super-fresh eggs from a smaller farm is a good idea.
There are a few different ways to melt the chocolate. One popular method is to bring the milk to a boil, then pour it over the chocolate. If you use this method, be sure to chop the chocolate into extremely fine pieces, and allow it to sit for at least a minute before whisking. Both of these strategies help ensure that there are no lumps in the mousse. If you do notice a lump, place the bowl over a pot of simmering water and stir constantly until the mixture is completely smooth.
Melting over a double boiler
Another popular method for melting the chocolate for mousse is to set it in a bowl over a pot of simmering water, then add milk that has been brought to a boil in a separate pot. When melting chocolate over a double boiler, avoid exposing the chocolate to water—it will cause the chocolate to seize up and be unusable.
Whisk in the egg yolk
The yolks provide additional richness. Be sure to whisk the yolks into the chocolate thoroughly, to avoid streaking and clumps of yolk.
Adding cream of tartar
When preparing the egg whites for whipping, you may want to add a pinch of cream of tartar, even if your recipe doesn't call for it. The cream of tartar will help strengthen and stabilize the foam, making it less fragile for folding into the chocolate mixture.
Add sugar when foamy
Whisk the egg whites and cream of tartar on high speed for about 30 seconds, or until they begin to look foamy and grow in volume. Without stopping the mixer, reduce the speed and add the sugar and salt in a small stream, then return the mixer to high speed.
Whipping to medium peaks
Once you've added the sugar, whisk the mixture on high speed for about 45 seconds. Stop the mixer and check to see how close you are to achieving medium peaks, which is a meringue that will only slightly slump over when the whisk is pulled from the bowl and inverted. This meringue is not there yet.
Watch carefully for medium peaks
Whisk at high speed for approximately 30 more seconds. Watch the bowl carefully. If the meringue starts to look at all dull or puffy, instead of smooth and shiny, the eggs are over-whipped and you'll need to start over with new egg whites. Over-whipped egg whites will cause the mousse to look and feel grainy.
Folding in the first addition
The hardest part of the process is the folding, because mousse is delicate and can easily deflate during this step. For best results, use a large bowl and the biggest rubber spatula you can find. To begin, add about 1/3 of the meringue to the chocolate mixture and begin to fold. For this first addition, the priority is to introduce all of the chocolate in the bowl (especially the annoyingly stubborn stuff down at the bottom) to the meringue, lightening it. You can be a bit more forceful and heavy-handed with this folding. Once the chocolate mixture has been introduced to some of the airy meringue, it will make it easier to carefully fold in the rest.
Once the first bit of the meringue has been combined with the chocolate mixture, add the rest of the meringue and slowly, gently begin to fold the two together. Use a light hand on the spatula and turn the bowl with your other hand, to avoid stirring instead of folding. Scrape around the edge of the bowl, then gently scoop up through the center and carefully fold the spatula back over the mixture, then turn the bowl to repeat.
Fold with caution
Careful folding will begin to bring the two mixtures together. The more they combine, the more you'll notice the mousse deflating, so work as quickly as you can, using the lightest possible touch.
Stop just when the mixtures are combined. A few very thin white streaks in the bowl is ok, especially when you plan to chill the mousse in individual portions.
Piping into glasses
The cleanest way to fill glasses or ramekins with mousse is to very gently fill a piping bag with the mousse and allow the mousse to run out into it with very little pressure to avoid deflating.
Spoon into ramekins
The other way to fill glasses or ramekins is to simply portion the mousse using a spoon. Smoothing the top with a knife can give the dessert a cleaner presentation.
Shorter chill for maximum lightness
Serve the mousse 45 minutes after chilling for optimal lightness and texture. The mousse may be stored for up to two days in the fridge, but it will become lose its volume and become dense.