Playing around with making my own yeast cultures, one of them has is white while fermenting. That started me thinking, "can I ferment Cow's Milk?".
One google search later there is Kumis, made from Mare Milk. But I am not sure how to go about it. This seems to be a nice list of steps:
Get enzyme that makes Glucose from Lactose.
Maybe add some more glucose.
Add yeast to the above.
Maybe add yogurt culture, to use the fats and proteins.
Let ferment for x hours / days.
Strain out solid bits.
Will this work?