The outer rind of citrus fruit containing aromatic essential oils. Remove the zest carefully using a grater, potato peeler or zester, depending on the intended use. Take care not to remove any of the white pith with the zest, because it can be very bitter.
The zest of citrus fruits can be used to add flavour to sweet or savoury dishes, or as a decoration or garnish. Lemon zest is a key ingredient in gremolata.