How to Rehydrate a Dehydrated Sourdough Starter

April 7, 2025

Tips before you get started:

Use lukewarm filtered or spring water. Avoid cold or hot water.
Use unbleached, unenriched, organic flour for the best health benefits. (This is optional.) Good quality flour brands: King Arthur, Bob's Red Mill, and Kirkland.
Make sure the lid on your starter jar is not too tight. The starter will release gas, and a tightly sealed container could burst. Tighten the lid all the way shut, then turn it back half a turn. The goal is to keep bad bacteria out and prevent mold but also allow the gases to be released.
Be patient. Starters may reactivate in as little as 3 days or as long as 1 week depending on its environment.
If at any time throughout this process you feel that your starter has become too stiff or too thin, add a little more flour or a splash of water until the desired consistency is reached. Do so in small amounts, such as a teaspoon at a time.
The starter is ready to use in a recipe when it's bubbling and peaks (or doubles in size) within 4-6 hours after a feeding. Note: It will fall after it rises; this is normal.

Sourdough Starter Rehydration Steps

What you’ll need:

☐ 10 grams Dehydrated Sourdough Starter
☐ ~ 1 ½ cups All-Purpose Flour or Bread Flour
☐ 7 oz Filtered Water
☐ 16 oz Glass Jar with Lid
☐ 34 oz Glass Jar with Lid or bigger
☐ Measuring Spoons and Cups
☐ Rubber Band (optional)

Instructions

Day 1:

In a 16 oz glass jar, add 10 grams of sourdough starter and 1.5 Tablespoons of filtered water and stir. Let it sit for 1 hour, so the starter softens.
Stir again. Add 1 Tablespoon of flour and mix until all flour is dissolved. Cover with a slightly loose lid. Let it sit in a warm spot for 24 hours (70-75℉ is ideal).

Day 2:

Add 2 teaspoons of water and 1 Tablespoon of flour to the starter. Mix well and cover. Let it sit in a warm spot for 24 hours. It should start to bubble after this feed, keep going!

Day 3:

Repeat steps from Day 2.

Day 4:

Add 1/4 cup water and 1/3 cup flour to the starter. Mix well and cover. Let it sit in a warm spot for 24 hours. If all goes well, it should start to bubble and rise after this feeding. You’re getting close!

Place a rubber band on the jar to mark the starting level of the starter, so you can see how much it rises. If it doubles (or "peaks") within 4-6 hours after this feeding, you can stop here and already start baking with your starter.

Day 5:

Transfer your starter to a bigger jar (34 oz or bigger). Add 1/2 cup of water and 1 cup of flour. Mix well and cover. Move the rubber band on the jar to mark the starting level of the starter, so you can see when it doubles. Let it sit in a warm spot and keep an eye on it.
Your starter should be actively bubbling and double in size (or "peak") within about 4-6 hours.

Congratulations! You successfully reactivated your starter and are ready to bake!

Ongoing Starter Maintenance:

You can now begin maintaining your starter with a regular feeding schedule. See below for Maintaining the Starter and Resources & Videos.

Troubleshooting:

If your starter isn't bubbling and rising as expected after day 5, discard half of the starter and repeat steps from day 5 every 24 hours until it does. Consider the temperature of its environment. If it's too cold, it could take longer to rise.
Tip: Some people like to place their starter on a heating pad on the lowest setting after a feeding if their house is too cold.

Sourdough Starter Rehydration Steps (with Photos):

Day 1:

Step 1

Add 10g dehydrated starter and 1.5 Tbsp filtered water and stir. Sit for 1 hour.

Step 2

Stir again.

Step 3

Add 1 Tbsp flour.

8 hours later

Mix well and cover. Sit in a warm spot for 24 hours.

Day 2:

Step 1

Add 2 tsp water.

Step 2

Add 1 Tbsp flour.

Step 3

Mix well and cover. Sit in a warm spot for 24 hours.

8 hours later

It's bubbling!

Day 3:

Step 1

Add 2 tsp water.

Step 2

Add 1 Tbsp flour.

Step 3

Mix well.

Step 4

Cover and sit in a warm spot for 24 hours.

Day 4:

Step 1

Add 1/4 cup water.

Step 2

Add 1/3 cup flour and mix well.

Step 3

Cover and sit in a warm spot for 24 hours.

4-6 hours later

If your starter doubles within 4-6 hours of feeding, you can stop here and start baking with your starter!

If not, continue to day 5.

Day 5:

Step 1

Transfer starter to a larger jar.

Step 2

Add 1/2 cup water to starter.

Step 3

Add 1 cup flour. Mix well and cover. Sit in a warm spot.

4-6 hours later

It's tripled in size and ready to bake with!

Maintaining the starter:

Once the starter is successfully reactivated, it can be stored at room temperature (if you bake daily) or in the refrigerator (if you bake weekly).
For regular feedings, after the rehydration process is complete, use a scale and weigh in grams.
Regular feedings should be ratios of 1:1:1, 1:2:2, 1:3:3, 1:5:5, 1:10:10, etc. of starter, water, and flour (depending on how much you will need for the recipe you're making).