Wash jalapenos in cool water and dry with paper towel.
Cut pepper stems off with a sharp knife. Cut in half lengthwise; remove and dispose seeds.
Spread peppers in one layer on dehydrator tray with cut side facing up without overlapping. Place in the dehydrator and dry at 125°F (52°C) for 12-18 hours or until dry enough to break apart when bent. Transfer dried peppers into blender and pulse until smooth.
Pour powdered pepper into a mason jar and cover lid tightly.
