Objective of the experiment

We made this experiment in order to understand why the yeast makes the dough rise.

Materials:

300 hg of flour, 200 ml of lukewarm water, some dehydrated yeast of beer, 1 teaspoon of sugar, a towel, one tureen, a glass.

What to make

- Melt the yeast in 200 ml of lukewarm water, then add a teaspoon of sugar
- Pour 300 g of flour in a tureen, then add the melted yeast and work well.
- Cover the dough with the towel and leave it to rest in a lukewarm place, waiting about an hour.

Observations

We observed that after 10 minutes the dough had begun to leaven and after 20 minutes it had doubled. Working again the dough, its volume reduced.

What happened?

The dough grows because a gas develops inside it. The gas is the consequence of the yeast fermentation (see also experiment " yeast and balloons "). To ferment, the yeast uses the starch of the flour.

... Finally our dough has became a tasty home made pizza!