Grating citrus zest removes only the flavorful, colorful outer layer of the peel, while peeling removes the entire peel, including the bitter white pith underneath. Zesting provides concentrated citrus flavor without the bitterness.
Zesting involves using a tool like a microplane, grater, or zester to carefully remove the outermost layer of a citrus fruit's peel. This outer layer, called the zest, contains aromatic oils that are packed with citrus flavor. The goal is to remove only this colored layer and avoid the white pith underneath. The pith is bitter and can negatively impact the flavor of your dish.
Peeling, on the other hand, involves removing the entire peel, including both the zest and the pith. This is typically done with a knife or peeler. While peeling is necessary for eating the fruit or using the entire peel in some recipes (like candied citrus peel), it doesn't isolate the concentrated flavor that zesting provides.
Think of it this way: zesting is like shaving off the flavorful surface, while peeling is like removing the entire skin.
When zesting, avoid pressing too hard. Gentle pressure ensures you only remove the zest and not the bitter white pith. Rotate the fruit frequently to avoid grating the same area repeatedly.