The method of homemade yeast, or sourdough, or natural yeast is the oldest method ever used for the rising of the dough in order to make bread: Dough from flour and water sits in room temperature to absorb the living organisms that are in the air and they feed from the flour’s amylum and initiate the fermentation. Usually, 4 days is enough, but you may need more. This type of homemade yeast, or a piece of dough from last time’s bread making is used to make bread. In this dough, various bacteria of lactic fermentation occur and they convert the sugars in lactic acid. With this homemade yeast, we get the initial dough which has a sour taste, because of the lactic acid. Lactic acid inhibits the development of all becteria except for the lactobacilli. After 12 hours approximately, we add more flour and water and the fermentation continues. This method may be harder, but the bread has a fuller taste and it’s preserved better.
How to make sourdough:
Mix 1 cup flour with 1/2 cup water, the basic ingredients. Others add more ingredients, such as honey, must, sourmilk, or a few drops of lemon juice to assist the fermentation. It’s advised that you knead thoughrouly (5-6 mins) so that the gluten is spreat even. Then we put the dough in a bowl, cover and leave in a warm place with no currents.
After the dough becomes sour, in 2 days, add another 1/2 cup water and 1 cup flour and knead again. Repeat another 2 times and the sourdough will be ready. If it’s not (not risen and not spongy enough), repeat one more time.
We put the sourdough, preferably, in a clay container, we oil the surface of the dough and we preserve in a cool place, or in the fridge for 1 week. It preserves much longer in the freezer. When we make bread, we will keep a piece of dough, which will be the sourdough for next time. This way we’ll always have sourdough.
The amount of sourdough necessary to make bread is 10% of the dough you are going to make, even though you can use a small amount of sourdough which, during the day, ferments with a small quantity of some of the ingerdients you will use.