At Gerwin Brand Bakery we are aiming to make the nicest and best tasting bread for you, mainly based on a sourdough culture, following old traditional methods.
What is sourdough bread?
Sourdough bread is a naturally fermented and leavened bread without the addition of commercial yeast.
To produce this kind of bread you need a sourdough culture, which contains wild yeasts, lactobacilli and enzymes. A sourdough culture is also called 'Levain'. Levain is the French word for leaven.
Natural yeasts are everywhere around us, in the air, on fruit, vegetables and grains. Yeast cells are living micro organisms which need food in order to survive and multiply.
A sourdough culture can be obtained when flour and water are mixed into a batter in roughly equal quantities and left exposed to the air for some time. After a few days bubbles will start to appear in the batter and it will slightly rise. This activity is caused by the wild yeast cells.
Alongside the yeast cells, acid producing micro bacteria will establish themselves in the culture. Together with certain enzymes present in the flour all these micro organisms start a fermentation process which changes the flavour of the batter and of any dough in which they are used and they make it rise. The yeasts consume the majority of the carbohydrates present in the flour and produce carbon dioxide and alcohol, the gases which make the dough rise. The yeasts however are unable to digest maltose, one of the carbohydrates in the flour. Incidentally the lactobacilli require this maltose to multiply. The contribution the lactobacilli deliver to the batter for this is that they create flavour components unique to sourdough bread. They also give it certain health properties and they protect the culture from other bacteria which could be harmful to us. This is how the culture survives if it is maintained well.
I will explain more about the health properties of sourdough in another chapter.