Buttermilk is a baking ingredient that isn't stocked by all grocery stores. Powdered milk, on the other hand, is an inexpensive staple that is found just about anywhere that sells groceries. Boxed powdered milk, when stored in a cool, dry place, is extremely shelf-stable and can last for over a year (although you should always check the "use by" or "best by" dates on the package). By using a small amount of buttermilk as a starter, you can make cultured buttermilk out of powdered milk.
Things You'll Need
- Powdered milk
- Bowl or jar (with a lid)
Measure the buttermilk according to how much you'll need. The mixture requires 1 part buttermilk to 8 parts reconstituted powdered milk. If you need 2 cups of buttermilk, measure ¼ cup of buttermilk.
Reconstitute the powdered milk. Following the package instructions, reconstitute eight times the amount of buttermilk you measured. From the example above, you will reconstitute 2 cups of powdered milk.
Combine the buttermilk and reconstituted powdered milk in the bowl or jar. Stir or shake to mix thoroughly.
Leave on the counter overnight or for eight hours. The buttermilk will culture the reconstituted powdered milk.
Use what you need and refrigerate the rest. Use by the date listed on the buttermilk package.