Many buttermilk and yogarts will not serve as starter cultures.....I dont know what is done by the processors to kill them, probably pasturizing after the culturing.
take my milk warn from the teat, put it in a sterilized jar with a Tbls. of starter and place it on top of the refrigerator. In 8 hours it is yogart(more time in cold wx and less in hot). I prefer buttermilk which I make the same way but with some cultured buttermilk as starter. Many buttermilk and yogarts will not serve as starter cultures.....
I am operating with the belief that none of my milk products are going to kill me or make me terrbly ill. Smell is sure subjective. I have to think cheese to smell stuff properly, cuz, sure, by my old standards these things have gone sour and are "ruined". But no, they have turned into something like cheese. I put the sour cream/feta (clabber) cheese one on pizza and it was delicious. The mozzarella-like one has been good on salads. So cool! This could so easily blossom into all out cheese making.
Since then I have been making yogurt using a yogurt culture. One time I was out of culture and used some store bought yogurt for the starter. It was a plain yogurt from Oikos.
Misfit I never would have thought of a wine making supply place for cheese starters but that makes sense. And Thanks