From where do the yeast came from

Question

From where do the yeast came from

Answer 1

Yeast are everywhere, in the air, on your food, on your body...  Yeast used in food and drink are strains which have been cultivated over the years to serve a certain purpose.  Most wild yeast is undesirable in food and drink although there are exceptions such as the natural airborn yeasts found in San Fransisco (sourdough bread) and the Senne Valley of Belgium (true lambic).  Essentially yeast are just another living thing carving out their place on Earth.