A couple of weeks ago, one of my friends told me about a little piece of kitchen magic. I can't quite remember how it came up in conversation, but she mentioned the possibility of making chocolate mousse from just water and chocolate. Devised by chemist Hervé This, the principle is simple: double cream whips up nicely, so why wouldn't it work to whip another emulsion with the same proportion of fat to liquid? This is edible chemistry, indeed.
I first tried out the mousse exactly as described, with just two ingredients: dark chocolate, and water. It's a strange experience, because even after you've watched someone else doing it on YouTube it really doesn't feel like it's going to work. And it continues to feel as if nothing is happening right up to the last minute, when suddenly, it thickens.
For this recipe, I replaced the water with strong coffee. I honestly wasn't sure whether this would work, or if I'd be throwing the whole lot away and starting again. When you're messing around with a method straight out of the bible of molecular gastronomy, you might think that it matters which molecules you're dealing with, but it was fine. I'm not sure the coffee added a lot to the taste, though.
I also added a layer of crunchy biscuit crumbs, and a layer of pureed raspberries, for a bit of variety.
Heston Blumenthal makes chocolate mousse
Raspberry Mocha Mousse
4 digestive biscuits (or graham crackers)
130g / 4½oz dark chocolate
130ml strong black coffee
- Grind the biscuits and divide between four ramekins. Push into the base of the pot.
- Puree the raspberries and spread over the bases to form a second layer.
- Melt the chocolate in the coffee, over a low heat.
- To make the mousse, stack two large mixing bowls with ice in between. Instead of using ice cubes directly, I found a freezer block that sat neatly in the bottom of my largest mixing bowl, and then put another bowl on top of the ice. This seemed to be enough, without any extra ice in the sides.
- Pour the melted chocolate mixture into the chilled bowl, and whisk with an electric mixer until it thickens. This may take some time.
- Transfer the mousse to a large piping bag and pipe over the raspberry puree.
- Smooth the top with the back of a spoon before serving.