Avoid the Wasteful Use of Buttermilk by Purchasing It in Powder.
I love buttermilk in baked goods, but most recipes require no more than 1/4 cup or so, and the remainder of a pint will usually simmer in the refrigerator until the expiration date. But that will all change soon because I now know the magic known as buttermilk powder.
If you enjoy drinking buttermilk (or pouring it onto torn pieces of cornbread and spooning it out of a glass like my grandmother), it might not be your jam, but for non-butter drinkers like me, it’s a game changer. … … The powder, which lasts for 9-12 months, allows you to reconstitute the exact amount needed for any recipe, reducing waste and saving time on the trip to the store every time you need 1/4 cup buttermilk. (Speaking of store, if you can’t find this pungent powder at your local grocery store, you can order it from King Arthur Flour or Amazon .)
Powdered Buttermilk – The Best Alternative to Used Buttermilk | Kitchen