In sweets, zest adds a colorful counterpoint to fresh berry fillings, dried fruit compotes, suave custards, and creamy frostings. Mellowed when baked, it insinuates its sunny personality into cakes and cookies. All citrus fruits are candidates for zesting. Lemons are the most popular. The zest from tangerines or blood oranges offers exquisitely flowery aromas.
Grapefruits yield a wonderfully complex zest.
Lime zest loses some of its kick when cooked, but added just before freezing to a sorbet or granita, it can't be beat. Look for firm fruit whose skin is clear of soft spots. I also try to buy organic produce when possible, especially citrus, since I'm using the outside of the fruit. The more fragrant the fruit, the more flavorful the zest. Scratch the peel of the fruit you're considering to release some of the volatile oils in the skin.