Chocolate Mousse

Yes. Use pasteurized eggs (sold in most supermarkets) or substitute 2 tablespoons of pasteurized egg white powder mixed with 3 tablespoons water for the raw whites, whisked and left to sit 5 minutes before whipping. The texture will be slightly less ethereal but still excellent.

Yes, up to 4 hours ahead. Cover with plastic wrap and refrigerate. Do not make it more than 4 hours in advance, as the mousse will gradually deflate and separate. For serving the next day, gently re-whip the cream and egg whites separately and fold into the chocolate immediately before serving.

You overfolded or the chocolate was too hot when you added the yolks, cooking them slightly. Overfolding deflates the whites—stop as soon as you see no white streaks. Always cool the chocolate to lukewarm (about 90°F) before incorporating yolks, and whisk the yolks in gradually to temper them gently.

Yes, use the same weight of good-quality milk or white chocolate. White chocolate mousse will be slightly sweeter and less intense; reduce the sugar in the egg whites to 1 1/2 teaspoons if using white chocolate. Milk chocolate will be softer and more approachable than dark.

Serve with fresh berries (raspberries, strawberries, or blackberries cut in half), small butter cookies (like shortbread), a drizzle of raspberry coulis, or a dollop of whipped cream. Avoid anything overly acidic before serving, as the acidity can break down the mousse's airy structure.

Mousse does not keep well beyond 4 hours and cannot be reheated. Store any leftovers covered in the refrigerator for a maximum of 24 hours (the texture will degrade), then discard. This dessert is best made the day of serving, ideally no more than 2–3 hours before guests eat it.