How to dehydrate sourdough starter– and why you should!

Dehydrating sourdough starter is super simple. All you need is active sourdough starter and a dehydrator.

Why dehydrate sourdough starter?

Dehydrating is a preservation method that leaves you with a shelf stable sourdough starter that may be crushed into a powder for easy storing. The yeast and good bacteria are still present. With a little flour and water, they can be reactivated. Here are a few other reasons why dehydrating sourdough starter is a good idea:

In case of emergency. Your refrigerated sourdough starter dies, spills, gets thrown out– life happens. Having a shelf stable starter can give you the peace of mind that if an accident happens you won’t have to start from ground zero. Some starters are more than just flour and water, they are family heirlooms passed down from generation to generation. Having a backup is especially important in a situation like that.

Gifting. The gift that keeps on giving! I recommend packaging 15g sourdough starter for the recipient along with instructions on how to rehydrate. (Copy directions below)

Selling. When I first decided to take a crack at sourdough baking the first thing I did was buy a dehydrated sourdough starter. Building my own wild yeast kingdom seemed daunting. Since then, I have baked hundreds of loaves of bread. I am so grateful for that little packet of dehydrated starter (link is to my own dehydrated sourdough starter you can buy) I purchased years ago!

Important tips for successfully dehydrating sourdough starter.

• Starter should be active! Peak activity is best to capture as much of that good yeast and bacteria as possible. This will increase the chance of a thriving starter once rehydrated.
• 120F and over will kill yeast cells. That would render the starter useless. Use the lowest temperature possible on your dehydrator. 88F-95F works well.
• Be patient. Dehydrating sourdough starter takes some time. Depending on how thick of a layer was smeared onto the tray, it could take up to 24 hours to fully dry.

How to dehydrate sourdough starter.

Step 1. Test your sourdough starter to see if its active. Drop a dollop of the starter into a glass of water. If the starter floats, it’s ready. Sometimes the presence of bubbles doesn’t always mean it’s ready to be used. The float test is easy and gives you assurance your starter is active.

Step 2. Spread a thin layer of starter onto a silicone tray. I use a tray that came with my dehydrator that was designed to make fruit leather. Depending on the size of the tray, 75g to 120g of starter is a good place to start. I use a scale to measure out 115g. Once dehydrated, I am left with around 90g sourdough starter.

Step 3. Set the temperature anywhere between 88F-95F. Slide the tray in and wait.

Step 4. Starter is ready when it is completely dry. The starter will resemble wafer crackers. Since the temperature is so low, oven mitts aren’t required to handle the trays. I check on the progress and sometimes move the starter around when it’s nearing ready.

Step 5. Let the starter cool completely before storing in an airtight container. I prefer to blitz up the starter into a powder for even easier storing.

Dehydrated sourdough starter will last indefinitely. Yep– that pretty much means as long as the world is turning, your sourdough starter will be alive!

How to rehydrate dehydrated sourdough starter.

1. In a glass container or large mason jar, combine starter, 1/2 cup bread flour and 1/2 cup warm UNCHLORINATED (no tap water!) water. Cover top with plastic wrap. Let stand at room temperature for 24 hours.
2. Your starter won’t look like much right now. Feed again, 1/2 cup bread flour and 1/2 cup warm water. Let stand at room temperature for 12 hours.
3. By now, your starter should have some bubbles. Feed again, 1/2 cup bread flour and 1/2 cup warm water. let stand at room temperature for another 12 hours.
4. Remove 1/2 cup starter and place in another glass bowl or mason jar. Discard the rest. To the starter, add 3/4 cup flour and 1/2 cup water. In 8-10 hours your starter should be ready to use. To test if it’s ready, drop a dollop into a glass of water. If it floats, it’s active and ready.

Sourdough starter reminders/tips.

1. Keep starter refrigerated when not in use.
2. Try to feed it often (especially in the beginning) to build up the wild yeast and good bacteria) Aim for at least weekly.
3. Never use all your starter, keep 3/4 cup. This is called your “Mother Starter.”
4. Feed starter 1 cup flour and 1 cup water for every 3/4 cup starter.
5. Never use chlorinated water, it will kill the yeast and bacteria. Even well water may have chlorine if you get your water treated. I use my refrigerator water and have had no issues but do your own research.