Think of chocolate Chantilly cream as a really thin ganache — whipped. Yes, you can make chocolate Chantilly cream with cocoa instead, however the cocoa butter in the chocolate makes a nice stabilizer, helping the whipped cream hold its shape. If you wish to supplement the real chocolate with more cocoa powder to boost the chocolate flavor, you can.
Begin by combining a cup of heavy cream with about two ounces of chocolate. These are 70% chips, but just about any chocolate will do.
Zap the mixture in the microwave for about 30 seconds on high and stir, then use as many more zaps of 15 seconds as you need to melt the chocolate completely (stir between each). The mixture will start out looking grainy…
…then smooth out as you re-establish your emulsion. Be advised, the darker the chocolate the more you’ll need to blend the mixture to avoid flecks. I got some as you can see above, but they were small enough that I really didn’t mind them. Use a stick blender to get a perfectly smooth emulsion. Refrigerate the mixture for about 4 hours until it’s quite chilly.
Pour the whole thing into the bowl a mixer fitted with a whip.
And whip to soft or stiff peaks, whichever you prefer. If you want to sweeten the cream along the way, you can do that as well.
Chantilly cream is a tremendously useful variation on standard whipped cream. Not only is it sweeter and more aromatic thanks to the added sugar and vanilla, it holds up much better than ordinary whipped cream. If you imagine an individual bubble in a whipped cream foam, that bubble’s skin is made of water reinforced by a network of proteins and fat molecules (lipids). When heavy cream is first whipped up, those bubbles are reasonably stable. As time passes, however, the water starts to drain away and/or evaporate and the bubbles start to pop. Sugar stabilizes the whip by combining with the water in the cream to form a syrup. Being thicker than water, the syrup is less inclined to drain away. And because sugar is so good at attracting and holding on to moisture, it prevents it from evaporating. The trick is adding the sugar after the foam has begun to form, so the milk proteins have time to uncoil and form their bubble-making network.
Make Chantilly cream by putting a cup of chilled heavy cream in the bowl of a stand mixer fitted with a whip. Add a teaspoon of vanilla extract and begin to whip.
When the mixture begins to form a foam, but is still fairly soupy — a bit shy of the “soft peak” stage — start sprinkling in an ounce of sugar. Powdered (confectioner’s) sugar is best because it dissolves more readily, but regular crystallized sugar will work also.
Whip another 30 seconds or so to soft peaks, or keep going to firm peaks, to a consistency that resembles buttercream. At this stage it can be piped, used to fill meringues or profiteroles, or used as a cake icing.
Chantilly cream can be flavored with all sorts of extracts (citrus are especially nice) as well as liqueurs like Grand Marnier or Cointreau.