Does anyone know what mixture of yogurt and whole milk will give a degree of sourness equivalent to cultured buttermilk? i have a wonderful recipe for ricotta cheese, but it calls for buttermilk which I rarely have around, but I always have yogurt.
You can use milk and white vinegar, I believe. It’s a tablespoon of white vinegar to about a cup of milk, I believe. Mix and let it stand for a few minutes.
If you are baking, you can sub yogurt for buttermilk one-for-one with no addition of milk. (I dislike the milk-and-vinegar sub that’s popular in some circles.)
If you are making CHEESE, however, I don’t know that yogurt will work as it’s a cultured product. You’ll get something edible, just not the same end result as if you’d followed the original recipe. There are lots of fresh cheese recipes that call for simply adding white vinegar to the milk – here’s one example: http://www.ehow.com/how_5346224_make-fresh-cheese-home.html
Note that if your recipe calls for heating milk with buttermilk to make cheese, you’re really just making a fresh cheese, not true ricotta. Ricotta is made from the whey left over from making other types of cheese.