The whites are gently incorporated into the chocolate mixture, which is mainly air, no secret, this is THE most delicate part of the recipe, let's see some tips to get it right.
The chocolate mixture
According to your recipe, you will put more or less things in it, and sugar or not, I remain a fan of simple things: dark chocolate melted in cream in a bain-marie, smoothed with a whisk, egg yolks are added, smoothed again with a whisk and that's it.
Associated tip: add the egg yolks only when the chocolate mixture is smooth with a whisk, and not too hot, just lukewarm, also with a whisk, then smooth carefully again.
Whipped egg whites
Related tips: It's not about making meringue, but you'll get much nicer whites if you "tighten" them by adding 20g of caster sugar (for 3 whites) halfway through. Their texture will be smoother, more creamy, and they will be easier to fold into the chocolate.
Mixing the 2As
I said, this is the difficulty, because you want to mix something very light, airy, with a very thick cream, and above all you want to keep the light side of the whites, to find it in the chocolate and form the mousse. So you can't go at it like a brute with a spoon, everything would fall back, it wouldn't be a mousse.Intuitively, you would perhaps pour the chocolate over the whites and mix? This would be a mistake, you would risk "breaking" the whites.
How do you do it?
You have to proceed in 2 steps:
It's a bit long and tricky, but that's where all the work is done. Stop when all the whites are well incorporated, there are no more "bundles of whites" not incorporated, be patient, in the end it is long to finish this incorporation ...
Divide into individual moulds and put in the fridge for at least 3 hours.
The above example is based on a chocolate mousse, but you can make all kinds of mousse on the same principle (whites + mixture) with instead of chocolate a (custard) cream with the fruits of your choice, or even a fruit coulis, but in this case you have to put a little gelatine in it while it is hot otherwise your mousse will not take.
A mousse is always a light and pleasant dessert, which finishes a meal in beauty, especially if it was a little rich.
In summary: The 3 secrets of a successful mousse are :
1) Adding the yolks with a whisk in a not too hot preparation
2) Whip the whites until they are stiff with a little powdered sugar
3) Incorporation in 2 steps, first we relax the mixture with a little whites with a whisk, and only then we incorporate gently with a maryse.
