1. Combine the lime zest, agave syrup, and sea salt in a 32 oz Mason jar.
2. Meanwhile, boil the water and add to the jar, stirring to combine.
3. Let cool to room temperature and add the lime juice. Refrigerate for 12 hours.
4. Strain through cheesecloth. To serve, combine 1 tablespoon of syrup with 6 oz of seltzer over ice, stir and garnish with a lime.
Great for adding to cocktails.
Reprinted from Infuse: Oil, Spirit, Water. Copyright © 2015 by Eric Prum and Josh Williams. Photos by Eric Prum and Josh Williams. Published by Clarkson Potter, an imprint of Penguin Random House, LLC.