Activate Your Starter: Feed your sourdough starter with equal parts flour and filtered water and cover with plastic wrap to ensure your sourdough starter is active and bubbly. Place in a warm spot and wait until it reaches its peak activity when starter doubles, between 4 to 6 hours.
Prepare the Baking Sheet: Line a baking sheet with parchment paper.
Spread the Starter: Spread a very thin layer of the wet sourdough starter onto the parchment paper. Use a spatula to spread it evenly, aiming for a thickness of about ⅛ inch (3 mm). If any thicker, it will take longer for your starter to dry out.
Air Dry: Place the baking sheet in a well-ventilated, dry area away from direct sunlight. Allow it to dry completely, which can take 1-3 days depending on the humidity and temperature. The oven would be the perfect spot for this to make sure it is not accessible to animals like cats or bugs like flys and fruit flies. Just make sure not to turn on the oven! This usually takes anywhere from 24 to 48 hours.
Break into Pieces: Once the starter is completely dry and brittle, break it into small pieces.
Grind to a Powder Form (Optional): For easier storage and rehydration, you can grind the dried starter into a powder using a food processor or blender.
Store: Place the dried starter chips or powder into an airtight container or plastic bag. Store in a cool, dry place away from direct sunlight. I have mine in my refrigerator. Properly stored, the dried starter can last indefinitely.
