Chocolate Mousse with Cream

Ingredients

Melted chocolate:

• 226 g (8 oz) bittersweet chocolate

Custard:

• 4 large egg yolks
• 189 g (3/4 cups) heavy whipping cream
• 25 g (2 tbsp) sugar

Whipped cream:

• 315 g (1 1/4 cups) heavy whipping cream
• 2 tbsp sugar

Directions

1. Prepare the melted chocolate:

• If using a microwave, use short bursts at low power.

• If using a double boiler, be careful to avoid exposing the chocolate to steam, because even that small amount of moisture can cause the cholocate to seize. Remove the water from heat and let it cool a bit before putting the chocolate over it.

• The microwave is the preferred approach, because it doesn't involve any moisture.

2. Make the custard:

• Beat the sugar into the egg yolks until it dissolves.

• Add the heavy cream.

• Cook over low heat, stirring constantly, until the mixture reaches 180-183°F (82-84°C), 5-10 min.

  • If the heat is too high, you might get "scrambled eggs" at the bottom of the pot.

  • I've read that custard will curdle if heated to 88-90°C. I'm not totally sure that this is true, but probably good to be careful.

• Process with an immersion blender for a few seconds, optionally.

3. Whisk the custard into the melted chocolate.

• Add the custard in three batches.

• After each addition, stir vigorously in small circles to create an elastic, shiny "kernel".

• Process with an immersion blender for a few seconds, optionally.

4. Chill to a temperature of 113-122°F.

• The chocolate sauce/custard should still be liquid.
• It will solidify if left in the refrigerator overnight.

5. Make the whipped cream:

• Beat cream and sugar until stiff peaks form.

6. Make the mousse:

• Stir 1/3 of whipped cream into cooled custard mixture.
• Gently fold in the rest with a rubber spatula.

Notes

2022/07/08:

• The chocolate custard solidified when I left in the fridge overnight, which probably means that I overcooked it. I only cooked it for ≈2 min, but I didn't stir it that frequently and I let it boil very briefly. Apparently I need to be very careful.

  I was able to use a double-boiler to melt the solidified custard without heating it above room temp. After that the mousse seemed fine. So maybe this is something I can work around.

2023/07/07:

• Heated custard for 3 min, reached 130°F. Chocolate separated when I whisked it in.

2023/07/15:

• Fitzy found that water can cause chocolate to seize, so we were careful to avoid exposing the chocolate to water. Specifically, we melted the chocolate using a microwave (rather than a double boiler) and we didn't add any vanilla extract (which can contain a substantial amount of water). I heated the custard for 10 min, and it reached 150°F. This worked: the chocolate didn't seize and formed a smooth, glossy custard. The custard still solidified overnight, though.

• I rewrote the recipe to incorporate more specific instructions from Valrhona, and to remove vanilla from the chocolate mixture.

References

• https://www.marthastewart.com/336783/chocolate-mousse
• https://valrhona-chocolate.com/recipes/cremes-and-mousses/custard-based-chocolate-mousse