What is a zester?

A zester is a kitchen tool used to peel the outermost layer of citrus fruits such as lemons, limes, oranges, and grapefruits. It is a small handheld tool that has sharp and narrow holes on its surface, allowing for the easy removal of thin strips or shreds of the fruit's zest. The zest is used to add flavor and aroma to various dishes, such as desserts, marinades, and cocktails. A zester can also be used to grate hard cheese, ginger, and other hard spices. Some zesters come with additional features, such as a channel knife to create decorative garnishes and a scraping tool to remove any remaining pulp from the fruit.