trapped into the gel. We obtain a jellified foam. Its formula is:
1) G+W _ G/W
2) G/W _ (G/L)/S.
What could be the maximum volume of air that can be inserted into this solution of gelatine?
III.16.3. A jellified foam from a stock:
III.16.3.1. Material :
· 500 g of white stock.
· 50 g of gelatine.
· Electric whisk (10 speeds).
· Hand with sticks of 0.7 mm of diameter.
1. Melt the gelatine in the hot white stock and homogenize.
2. Put the mixture in bowl and use the electric whisk (speed 10). Cool the mixture by putting the bowl in
frozen water, the gelatine would get hard.
3. Stop the whisk, when the mixture gives a firm foam and when the gelatine sets in gel. Store it in the
fridge or use it directly.
This experiment was done with different concentrations of gelatine. The results and the
observations for each gelatine concentration is in Appendix 13.
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III.16.3.3. Results :
III.16.3.4. Discussion/ Interpretation:
The foam, clearer than the solution, increases in volume. Then, the gelatine starts to set in gel:
the foam darkens, the volume of air bubbles decreases and their number increases. When all the liquid is
transformed into foam, the preparation is almost ready, but it is necessary to avoid the making of lumps.
Put in the fridge (+ 2°C), the foam hardens into a gel. In the fridge, the foams finishes to set, and the
texture is different than a gelled foam not cooled.
The tests reveal that a concentration in gelatine higher than 6% doesn’t give a good result.
Indeed, the solution of gelatine sets in the bowl because the mixture is too viscous to be whisked. When
the concentration of gelatine is lower, the volume of solution not used to make foam is smaller and also,
the size of the bubbles are bigger.
In gels and foams, the taste is sweeter, less strong than the one you can find when you eat the
tasty food. The idea is to use a gelled foam in order to moderate a taste that is usually strong. For
example, the acidity of a lemon juice or the spicy part of a hot pepper were tested in a gelled foam.