zest

Zest refers to the outer colored layer of citrus fruit peel, the part just beneath the surface skin, which contains essential oils that provide bright, concentrated aroma and flavor. It is distinct from the white pith underneath, which is bitter.

In cooking, zest is usually obtained with a microplane grater, a zester that makes thin strips, or a sharp peeler. The goal is to remove only the colored layer, avoiding the white pith. Lemon, orange, lime, and grapefruit zests are common, but other citrus such as bergamot or yuzu can also be used. The oils released when zest is grated or cut are highly volatile, so zest is often added during preparation to perfume dishes, or stirred in near the end of cooking to preserve aroma.

Zest is primarily used to flavor desserts, sauces, marinades, beverages, and savory dishes. It adds a citrusy brightness without the acidity of juice. Fresh zest provides more aroma than dried zest, though dried or frozen zest can be stored for later use. For storage, place fresh zest in an airtight container in the refrigerator for up to about a week, or freeze for longer storage.

In non-culinary use, the word zest can also mean enthusiasm or energy, as in “zest for life.” Etymologically, zest comes from the French zeste, ultimately from Italian scorza, referring to the peel.

Safety notes include washing or choosing organic or unwaxed fruit to minimize pesticide residues on the zest.