Feed your starter for 4–12 hours before starting this process.

Line a large wire cooling rack or sheet pan with parchment paper.

Measure out 1/2 cup of sourdough starter and spread it as thin as you can on the parchment.

Once the starter is spread evenly and as thinly as you can, place the rack or pan in a dry, cool place, such as on the counter or in a pantry.

Let the starter dry for the next 24-96 hours. The length of time will depend on the humidity and temperature of your home. It can take up to a week.

Once the starter is completely dried, break it into pieces and add them all to a blender.

Blend the dried starter for 20 seconds, then pour it into a Ziplock bag or container.

Store it in a cool, dry place indefinitely.