Refresh your starter: Feed your starter 4–8 hours before drying so it’s at peak activity. You want it bubbly, doubled, and smelling pleasantly tangy.

Prepare your surface: Line a sheet tray with parchment or a silicone mat. This makes removal easy once it’s dry.

Spread it thin: Scoop 1–2 cups of active starter onto the parchment. Use an offset spatula to spread it into a very thin, even layer—aim for about 1–2 millimeters thick. Thin layers dry faster and more evenly.

Dry at low temperature: Air-dry at room temperature in a dry, well-ventilated spot, away from direct sun. If using a dehydrator, set it to 95°F–105°F (35°C–40°C). Avoid higher heat to protect the microbes.

Wait until completely brittle: Drying time varies—anywhere from 12–48 hours depending on humidity and thickness. The starter is ready when it’s fully crisp and snaps cleanly with no soft spots.

Break into flakes: Peel the sheet off the parchment and crack it into small flakes. You can also pulse gently in a food processor to create coarse crumbs, but avoid turning it into powder.

Package for storage: Transfer flakes to an airtight container or zip-top bag. Press out extra air. Add a silica gel packet if you have one to keep moisture at bay.

Label and date: Note the flour type and the date you dehydrated it. Most dehydrated starters keep well for 1–2 years when stored properly.

Store smart: Keep in a cool, dark, dry place. A pantry works; the freezer is even better for very long storage.