Perhaps a bit misleading of a title. I intended to make a soft cheese (Ricki's Bondon recipe, essentially a cream cheese with whole milk) using a buttermilk culture. I forgot to add rennet, and it didn't curdle. In 36 hours. I could smell the buttermilk, though, very strongly, so I figured the culture was still good. Adding rennet that late would probably have been a disaster.
So, I took Linuxboy's mozzarella recipe, took the 1.5 gallons of buttermilk-cultured milk, added another 1.5, and tried to make mozzarella. Found out my thermometer's broken, couldn't find my pH meter. The rennet got me a nice clean break, and everything from there went basically perfectly. I've never made a better mozzarella! I stretched one ball, and it was a bit on the under-done side, and came back in 2 hours and it stretched amazingly. I probably could have let it go a little longer, or kept it a bit warmer, but without a thermometer and with a mesophilic culture, I played it really conservative on the temperature. Started early enough in the day to have some time to wait.
Mozz is really challenging, and I was surprised I was able to pull it off at all. Pizza time tomorrow