Today I have learned something about Wild Yeast and Sour Dough Starters. I have been aware that there is a product called Sour Dough Yeast. What I didn't know is that it is about next to worthless without understanding the concept of a Sour Dough Starter.
So what is Wild Yeast? It is a form of yeast that is always present, like the mitichlorians of the force in Star Wars. It is in the air, in flours and covers the surfaces of many vegetables and fruits. Commercial Active Dry and Instant Yeasts have largely replaced it as purchasable Yeast products. But these will not produce that Sour Dough flavor.
In truth, one does not have to purchase a Sour Dough Yeast as it is already everywhere. But the thing that must be done is to create a Sour Dough Starter, a batch of watery flour that is allowed to sit at a cool temperature for several days and allow the natural Wild Yeast to replicate and ferment the mixture.
So what is a Sour Dough Starter? It is an open container of watery flour mixture that is allowed to sit and ferment by the naturally occurring Wild Yeast. It should be kept at a cool temperature as Wild Yeast will not survive at elevated warm temperatures. After just two days, a Sour Dough Starter will begin to bubble as the fermentation process begins to give off gas. It may take up to a week or more to produce a good Sour Dough Starter which can then be mixed into a Bread Dough. It may be wise to turn or stir the Starter periodically while it is fermenting. Once mixed into a Bread Dough, it should be treated like Active Dry Yeast and be allowed to sit for a time to begin leavening the Bread Dough.
There are several terms or names for Sour Dough Starter and these include Starter, Starter Sponge, Mother, Mother Sponge, Levain, Biga, Chef and Poolish. These are all types of what is more technically known as preferments and they may vary from one to another in some details.
