Chefs incorporate zest into fish or meat marinades by grating the outer layer of citrus fruits directly into the marinade mixture, adding bright, aromatic citrus oils without the bitterness of the pith.
Zest is the outermost, colorful layer of citrus fruit peel, containing concentrated citrus oils that impart a vibrant flavor and aroma. Chefs use zest in marinades to add a bright, fresh citrus note that complements the flavors of fish and meat. The process involves carefully grating the zest using a microplane, zester, or fine grater, ensuring only the colored part of the peel is removed, avoiding the white pith underneath, which is bitter. The zest is then added to the marinade mixture, which typically includes acids (like citrus juice or vinegar), oils, herbs, spices, and other flavorings. The citrus oils in the zest infuse the fish or meat during the marinating process, tenderizing the proteins and adding a complex citrus flavor profile. The amount of zest used depends on the desired intensity of citrus flavor and the quantity of the marinade.
To maximize the flavor of citrus zest, gently massage it with salt or sugar before adding it to the marinade. This helps release the essential oils and enhances their aromatic properties.