The world's simplest chocolate mousse

Hervé This is a culinary genius.  But perhaps you already knew that.  You may have heard his name whispered in hushed tones between your foodie coworkers, or stumbled across a YouTube video of him doing mad food science.

But if you needed further proof, I present the two ingredient chocolate mousse.  (Ok, really just one ingredient.  Water doesn't count.  It's chocolate mousse, made with chocolate.  Just chocolate.)  It's delicious, rich, stupidly simple, vegan, kosher, halal, dolphin safe, etc., etc.  If you can eat chocolate, you can eat this.  You can jazz it up with liqueurs or fruit, dollop whipped cream on top, or just savor it, bite by chocolatey bite.

Here is the cool science part: to make this, you're basically doing the same thing with chocolate that you do with whipped cream.  When you whip cream, you're incorporating tiny bits of air into a water-fat emulsion, and when there's just the right amount of fat in the emulsion, the air gets trapped, making a stable foam.  The reason why you add water to the chocolate is to create the right ratio of water to fat.  Once you have that nailed, you whisk like mad as it cools, and voila, mousse.

As a bonus, if you over-whisk it, or screw up the ratio, all you have to do is remelt it, correct the proportions if needed, and rewhisk.  Try doing THAT with whipped cream.  (Wait, can you do that with whipped cream?  Gonna need to look into that.  I'll report back at some later date.  Right after I figure out how to do this with olive oil and water, because infused olive oil whipped foam.)

Without further ado, or any more gushing about chemistry, here is the recipe.  Yes, you can halve or double it.

• 6 oz water (3/4 cup)
• 8 oz good quality chocolate at your favorite strength.  (We used a mix of Scharffen Berger, some Rich Milk and some 62%, but you can use anything from white chocolate to baking chocolate.)

If you like, you can substitute some of your favorite liqueur or fruit juice for the water.  We swapped in a tablespoon of a ruby port.  We also threw in blueberries and garnished with whipped cream.  We're big on lily-gilding around here.

Prepare a large bowl full of ice cubes and water, with a smaller bowl inside it, large enough to hold at least 4 cups.  (You may recognize this setup if you've ever made whipped cream by hand.) While you're at it, set out 4-6 mid-sized ramekins. We tossed the blueberries on the bottom.

Chop the chocolate finely.

Put the water (and liqueur if you're using it) into a sauce pan over low heat, and add the chocolate slowly to the water.

Whisk continuously, until it all melts.

As soon as it's all fully melted, pour the mixture into the small bowl on ice, and whisk vigorously!  I prefer to do it by hand, and it sets up slightly faster than whipped cream does, but you could use egg beaters if you prefer.  Keep an eye on it, and don't over whisk.

When it starts to form very soft peaks and follow the whisk when you pull it out, pour it immediately into the ramekins.

Let it set up for a bit at room temperature, but don't chill it (it will get really hard in the fridge, unlike whipped cream.)  Once it's firmed, garnish it however you prefer.


Troubleshooting tips:
If it doesn't thicken, reheat and add more chocolate.
If it's too thick and too hard, reheat and add more water.
If it's grainy, you over-whisked it.  Reheat and rewhisk.