Zest

Zest is the bright, colored outer layer of the skin of a lemon, lime, orange or grapefruit. It holds most of the fruit's fragrant oils and adds strong citrus flavor without adding sour juice. To zest means to remove this layer and leave behind the white pith underneath, which is bitter.

How to do it

1. Wash the fruit in warm water and dry it. Many citrus fruits are coated in wax. If you can, buy unwaxed fruit when you need zest.
2. For fine zest, run the fruit over a rasp-style microplane in one direction, turning it as you go so you take only the colored layer.
3. For long strips, use a vegetable peeler with light pressure. Scrape off any white pith on the back with a knife.
4. For thin curls, use a zester tool with small round holes.
5. Zest the fruit before you cut or squeeze it. It is much harder afterward.

How to tell it is done

Stop on each patch as soon as you see white. The zest should be bright and fragrant. White flecks mean you went too deep.

How to use it

• Fine zest in cakes, cookies, dressings and marinades. Rub it into the sugar with your fingers first to release more oil.
• Strips in braises, syrups, tea and mulled wine, then lift them out.
• Mixed with parsley and garlic for gremolata.
• One medium lemon gives about 10 to 15 ml (2 to 3 teaspoons) of fine zest.

How to store it

Fine zest dries out within a day in the fridge. Freeze extra zest in a small sealed container or bag for up to 3 months. Freeze the zested fruit too, or use its juice within a few days, because it dries out without its peel.

Common mistakes

• Grating into the white pith. It makes the dish bitter.
• Pressing hard on the grater. Light strokes take only the colored layer.
• Zesting fruit you have already juiced. It is soft and hard to grip.
• Adding zest too early to a long-cooked dish, where its fresh flavor fades.

In recipes

"Grated zest", "finely grated rind" and "zest of 1 lemon" all mean the colored outer layer only. "Peel" may include the pith. See peel.