I've been making yogurt these past several months, with great success.
After the holidays, with excess buttermilk I went looking for ways to use it up. I became intrigued with the recipe to make cream cheese/sour cream: a half gallon of milk warmed up to 100 degrees, add 1/4 c buttermilk and let it sit at room temp for 24 hours. I let it sit inside the oven ( since it is currently around zero temps, and we keep the house cold) and it cultured up nicely. strained it, etc.
The question: why does milk for yogurt need to be heated to 180 ( I understand it is supposed to break down a protein--or something) and the buttermilk to make cream cheese does not need to be heated to that same type of temp.
Just curious about this difference.