Slice beets 1/8-inch thick for the best crisp — thinner slices can burn, thicker ones stay chewy. Flip the chips after 15 minutes and watch them closely during the final 10-15 minutes to prevent burning. Squeeze out as much cucumber moisture as possible for a thick tzatziki, store beet chips in an airtight container at room temperature once cooled, and keep the tzatziki refrigerated until serving.