Parts of the fruit

What Is Citrus Zest?

Zest: The colored outer layer of a citrus peel, where most of the fruit's aromatic oils are stored. It carries the fragrance of lemon, lime or orange without the juice's sourness.

In the kitchen

Zest is what you get when you grate or peel off only the bright outer skin. Underneath it sits the white pith, which is bitter, so a good zester takes the color and leaves the white behind.

Because the oils live in the zest rather than the juice, zest is what makes a lemon cake taste like lemon instead of just tart. Rubbing zest into sugar before baking spreads those oils through the whole batter, and zest freezes well, so it is worth taking before you juice a fruit.

One medium lemon gives roughly a tablespoon of zest. Wash and dry the fruit first, and use unwaxed or scrubbed fruit when the zest is the star.