"Mousse" is the French word for "foam", while "Chocolat" is of course French for "chocolate". Consequently, "Mousse au chocolat" translates as "foamy chocolate", and is one of a number of foamy desserts (many of which are fruit based).
With a few rare exceptions, all chocolate mousse recipes have two ingredients:
- Chocolate, which is of course the essential element of the dessert, and
- Egg white, which is whipped into a foam and then added to the melted chocolate to provide the light and foamy texture, which is the essence of the recipe
To this, depending on the recipe, additional ingredients can be added to change the taste and texture of the dessert. Common examples are:
Sugar - Mainly to make the dessert sweeter, as dark chocolate can otherwise be too bitter for most people.
Cream - This gives the dessert a softer and lighter texture. For recipes using dark chocolate (some use white chocolate), this ingredient makes the dessert taste more like milk chocolate than dark chocolate.
Egg yolks - Adds a rich taste to the dessert, plus uses the yolks left over after one has used the egg whites.
Butter - Like egg yolks, add a richness to the dessert.
Flavourings - Many different flavourings can be added, the most popular including: vanilla, orange and coffee. One could argue that this is not "authentic" chocolate mousse, but if people enjoy it, why not introduce some variety?
Decoration - After the dessert is prepared, decoration is sometimes added to the top. Most commonly, this is flakes or sticks of chocolate, which not only is visually interesting but also adds contrast (in both taste and texture) between the chocolate flakes and the underlying chocolate mousse. Other common decorations are cream or berries (raspberries and strawberries are often used). A less common but elegant edition is mint leaves.
Of these additional ingredients, sugar is present in every recipe I've ever seen and cream is present in most. The other items are frequently, but far from always used.
The exact date of the first chocolate mousse recipe is unknown. However, it is believed to be from the second half of the 1800s. In 1977, in New York City, chef Michel Fitoussi created a white chocolate mousse, which for a period of time was extremely popular (up until then chocolate mousse always used dark chocolate). Now one can find both types of chocolate mousse, but in France it is almost always based on dark chocolate.
We have a number of recipes at Chocolate Mousse (Mousse au Chocolat).