When you first get your hands on a starter culture for making homemade yogurt or buttermilk, you might be antsy to get started right away!
But if you aren't ready to activate your freeze-dried starter right when you receive it, you can maximize its shelf life by storing it in the freezer. (You can learn more about How Long Cultures Last here.)
Once you've activated the starter culture, your homemade yogurt or buttermilk is generally good for eating for up to 2 weeks, when stored in the refrigerator.
For re-culturing, we recommend using the culture within 7 days to make a new batch. If a longer break is necessary between batches, preserve some active cultures by freezing or drying. Neither method is 100% foolproof, but our culturing community reports a fair amount of success with either.
Short Breaks, Up To 4 Weeks - Freeze The Culture!
Freezing the Culture
- Put fresh, active starter in clean freezer-safe containers. We find ice cube trays to be quite convenient.
- Fill each cube with the amount of starter that it will take to culture 1 cup of milk. (About 1 Tbsp.)
- Once frozen, store the cubes in an airtight container in the freezer.
Making Yogurt or Buttermilk Again
- When ready to make yogurt or buttermilk, remove enough from the freezer to make a new batch, 1 cube per 1 cup of fresh milk.
- Let the cube thaw gradually in the refrigerator. Sudden changes in temperature can be harmful to the culture, so we recommend thawing it in the fridge.
- Prepare your milk according the instructions for your starter culture and add the thawed starter cube to the milk.
- The longer the starter is frozen, the less potent it will be as a starter culture. It may be necessary to use up to twice the amount if the culture was frozen for 3-4 weeks.
Long Breaks, Up To 3 Months - Dry The Culture
Drying the Culture
- Spread a small amount (2 Tbsp.) of starter on a piece of unbleached parchment paper.
- Leave the starter to dry in a warm, safe spot no more than 80°F.
- Once it is completely dry, store in a zip lock bag in the refrigerator.
- Under ideal conditions, the starter will keep for up to a few months.
Making Yogurt or Again
- To rehydrate the yogurt or buttermilk, follow activation instructions included with the starter or watch one of our How-To Videos on Making Yogurt.