When zesting fruit, remove only the colored outer layer (the zest) and avoid the white pith underneath, as it is bitter. Aim to remove just enough to get the flavorful oils without including any of the pith.
Zesting involves extracting the flavorful oils from the outermost layer of a fruit's peel. This layer, called the zest, contains aromatic compounds that add a bright, citrusy flavor to dishes. The key is to remove only this colored layer and avoid the white, spongy layer beneath, known as the pith. The pith is bitter and can negatively impact the taste of your recipe.
To zest effectively, use a zester, microplane, or even a vegetable peeler. If using a vegetable peeler, carefully shave off thin strips of the peel. Then, use a knife to finely mince the strips. With a zester or microplane, gently run the fruit across the blades, applying light pressure. Rotate the fruit as you go, ensuring you're only removing the colored part of the peel. Stop when you start to see the white pith appearing.
The amount of surface area you zest depends on the recipe and your personal preference. However, a good rule of thumb is to zest until you have enough to measure the amount called for in the recipe, being careful to avoid the pith.
Before zesting, thoroughly wash and dry the fruit to remove any dirt or residue. This ensures that you're only adding clean, flavorful zest to your dish.