- Peels from 2 pounds mixed citrus
- Spice mill
- Preheat oven to 150° or as low as it will go. Using a vegetable peeler, remove peel from 2 pounds mixed citrus. Place peels in a large saucepan and pour in cold water to cover. Bring to a boil and cook 1 minute. Drain; rinse peels under cold water. Repeat twice more.
- Spread peels out on a wire rack set inside a rimmed baking sheet and bake until dry and brittle, 18–24 hours.
- Working in batches, grind peels in a spice mill to a fine powder.