I have been making Chevre Cheese which uses Buttermilk. You only use a half a cup with each batch of the cheese. The smallest container of buttermilk I could find was quart size. I wasn't using the buttermilk before it would go bad so I have been dumping a lot of it, and that was frustrating because it isn't cheap.
I was reading through some cheese making information and found a section on How To Culture Buttermilk. Now why didn't I think of that?? Very easy.
One quart of Goat Milk2 Tablespoons cultured Buttermilk
Warm the milk to 72 degrees. Stir in Cultured Buttermilk.Allow mixture to set covered, at room temperature for 12 hours or more. When thick, refrigerate.
I get my cultured buttermilk from a local grocery store. I always check the expiration date and get the freshest milk.
You can save some buttermilk from a previous batch to start a new batch. Just like yogurt!