Zest is the peel of the citrus fruit grated finely. Zest comes from the rind of citrus fruits. You can zest everything from lemon to orange. And, of course, limes! Lime zest is a fun ingredient to add to tacos, salsa, dips, and more. You can kick up the flavor of just about anything with a little lime zest. It's even perfect for using in tasty dessert recipes. With the right tools, zesting a lime is easy.