How to Dehydrate Sourdough Starter – The Sourdough Science Method

There are three ways to dehydrate sourdough starter for long-term storage or sharing. Here’s how we recommend doing it:

Method 1: Room Temperature Drying (Easiest but Riskier)

1. Take a small amount of your active sourdough starter and spread it thinly on a piece of baking paper. Flatten it out into a very thin layer.
2. Leave it to air dry at room temperature for around 24 hours.
3. Once completely dry, it will start to crack and break apart easily.
4. Scrape off the dried flakes and store them in an airtight container or a zip-lock bag.

Note: This is the easiest method but also the riskiest because mold can form in humid environments.

Method 2: Oven Drying (Common but Mid-Risk)

1. Spread a thin layer of sourdough starter on a piece of baking paper.
2. Set your oven to a very low temperature, ideally between 40°C and 50°C, with the fan on.
3. Place the baking sheet in the center of the oven and dry for several hours (usually around 12-18 hours).
4. Be cautious not to overheat, as excessive heat can kill some of the beneficial bacteria in the starter.

Method 3: Dehydrator Drying (Safest but Requires Equipment)

1. Spread a thin layer of sourdough starter on a piece of baking paper or a dehydrator sheet.
2. Set the dehydrator to 35°C and dry for around 18 hours.
3. Once fully dried, scrape the starter into flakes and store them in an airtight container or zip-lock bag.

Note: This method is the safest and most controlled way to preserve the starter’s beneficial bacteria and yeast.