III.16.4. Slightly acid and sweet foam, like a meringue.
In a meringue, the sugar (that is hygroscopic xxix) allows to firm up the mixture, and also to
decrease the intensity of the acidity. It is what we want to introduce in foam with gelatine.
III.16.4.1. Material :
· 200 g of squeezed lemon juice
· 5 g of gelatine Rousselot (leaves)
· 5 g of honey
· 100 g of sugar
· Electric whisk (10 speeds).
The method is the same than previously, where the sugar and the honey are dissolved in the
Figure 32 : white stock foam.
Figure 33 : different
steps during whisking
44 / 63
III.16.4.3. Results :
The result is very satisfactory regarding the lightness, the smoothness and the great taste of
lemon. Also, the use of sugar sweetens the mixture and helps to get it firm.
III.16.4.4. Discussion/ Interpretation:
The sugar improves the setting of the foam, its homogeneity and the regularity of bubbles. It gives
a shiny and smooth effect.
At t + 72h, the foam sets but starts to fall down; also, big bubbles (diameter > 4mm) appear.
Nevertheless, such preparations are only done before the service, their use several hours later is not
possible for the restaurant. To save time, the preparation can be however prepared in advance, kept in
Recipe of a lemon gelled foam of the restaurant:
· 2 l of tap water
· 2 kg of caster sugar
· 1 l of fresh squeezed lemon juice
· 70 g of gelatine (3,5 %)
1. Make 1 l of syrup with the sugar and the water by reducing the mixture of an half.
2. Add the lemon juice and the gelatine into the hot syrup, cool in at room temperature and whisk it cold.
The pastry cook masters this technique, thus the transfer of this principle is totally practicable for
the team of the restaurant.
Make foam with a cold solution seems practicable, but the final result is not as foamy as
expected. Indeed, whisking a cold mixture is less efficient than whisking a hot mixture on ice. In terms of
quality, this technique is not really interesting.
This recipe was put online on Pierre Gagnaire's website, in “recipe of August”, where Pierre