Gather your peels and arrange them in the dehydrator. Be sure to use a mesh liner that came with your dehydrator, or line each sheet with parchment paper. Set them in a single layer with minimal to no overlap.
Set dehydrator to 115℉ and run for 12 hours. The peels are done when they are completely brittle with no bending.
Cool. Let peels cool completely.
Grind. Using a spice grinder or coffee grinder, pulse the peels until they turn into a find powder. Work in batches.
Store. Store the powder in an airtight container up to 1 year.
Notes
You can vacuum seal or dry can this for longer storage, up to 10 years.