How do I dry or freeze sourdough starter for long-term storage, and how do I reactivate it later?

Question

How do you dry or freeze a sourdough starter for long-term storage? Learn the methods for preserving your starter and how to reactivate it later.

Answer 1

You can dry sourdough starter by spreading it thinly on parchment paper or dehydrating it. To freeze, portion it into airtight containers. Reactivate dried starter by rehydrating with water and flour, and frozen starter by thawing and feeding it regularly.

Detailed Explanation:

Drying or freezing sourdough starter is a great way to preserve it for long-term storage, especially if you won't be baking regularly. Here's a step-by-step guide for both methods:

Drying Sourdough Starter:

1. Prepare: Feed your starter as usual and let it rise until it's active and bubbly. This ensures it's at its peak for drying.
2. Spread Thinly: Spread a very thin layer of the active starter onto parchment paper or a silicone baking mat. The thinner the layer, the faster it will dry.
3. Dry: Let the starter dry completely at room temperature. This can take anywhere from 1 to 3 days, depending on the humidity. You can also use a dehydrator at a low temperature (around 95°F or 35°C) to speed up the process. The starter should be brittle and easily breakable when fully dry.
4. Store: Once dry, break the starter into flakes or grind it into a powder. Store it in an airtight container in a cool, dark place.

Freezing Sourdough Starter:

1. Prepare: Feed your starter as usual and let it rise until it's active and bubbly.
2. Portion: Divide the active starter into small, airtight containers or freezer bags. Consider freezing in portions that you would typically use for a single bake.
3. Freeze: Place the containers or bags in the freezer.

Reactivating Dried Sourdough Starter:

1. Rehydrate: Combine 1 tablespoon of dried starter with 2 tablespoons of lukewarm water in a clean jar. Let it sit for about 15-20 minutes to rehydrate.
2. Feed: Add 2 tablespoons of flour (equal parts all-purpose and whole wheat works well) to the mixture and stir well.
3. Observe: Cover loosely and let it sit at room temperature. You may not see activity right away.
4. Repeat: Feed the starter every 12-24 hours with equal parts water and flour (e.g., 2 tablespoons water and 2 tablespoons flour). It may take several days or even a week for the starter to become active and bubbly again. Be patient!
5. Use: Once the starter is consistently doubling in size within 4-8 hours after feeding, it's ready to use for baking.

Reactivating Frozen Sourdough Starter:

1. Thaw: Thaw the frozen starter in the refrigerator overnight.
2. Feed: Once thawed, discard half of the starter and feed it with equal parts water and flour (e.g., 1/4 cup water and 1/4 cup flour).
3. Observe: Let it sit at room temperature. It may take a few feedings for the starter to become active again.
4. Repeat: Feed the starter every 12-24 hours until it is consistently doubling in size within 4-8 hours after feeding.
5. Use: Once the starter is consistently doubling, it's ready to use for baking.

Pro Tip:

When reactivating either dried or frozen starter, don't be discouraged if it takes a while to become active. The yeast and bacteria need time to wake up and multiply. Using whole wheat or rye flour for the initial feedings can help provide extra nutrients to kickstart the process.