The Yellow Citrus Family: Lemons, Yuzu, Citron and More

Key takeaways

• Citrus gives three separate ingredients: aromatic zest, juicy segments and the white pith between them, so use each part on its own.
• Lemon is the standard yellow citrus; Meyer lemon is gentler and more floral; yuzu is prized for zest and juice; citron has thick, mild pith and little juice; grapefruit and pomelo are large and tart to mildly sweet.
• Citrus does not ripen after picking, so choose fruit that feels heavy for its size, with fresh-looking, evenly colored skin.
• Grapefruit and some related citrus, including pomelo, can interact with certain medicines; ask a doctor or pharmacist.
• Citrus keeps for several days at cool room temperature and generally weeks in the refrigerator; juice and zest freeze well.

What makes citrus a family of peel, juice and perfume?

Citrus is one of the most useful fruit families in the kitchen. Many citrus fruits turn yellow when ripe, and nearly all of them offer three separate ingredients in one package: the aromatic oily outer peel, the juice-filled segments, and the bitter white layer in between. Learning to use each part separately is the key to getting the most from lemons, yuzu, citrons, grapefruit and their relatives.

Citrus has a long history of cross-breeding, and the family tree is complicated. Many familiar fruits are hybrids, and names vary from country to country. This guide sticks to general descriptions and avoids exact claims about origins or numbers.

Lemon

The lemon is the standard yellow citrus. Its juice is sharply acidic, its zest is intensely fragrant, and it is used in drinks, dressings, sauces, desserts and as a seasoning that brightens savory dishes. A squeeze of lemon at the end of cooking can lift flavors much like salt does, which is why professional cooks reach for it so often. USDA FoodData Central lists raw lemon without peel at about 2.8 g of fiber and 2.5 g of total sugars per 100 g.

Lemons are usually sold already yellow, but some are picked slightly green and still ripen on the shelf in appearance. Choose fruit that feels heavy for its size and has a fine-grained, slightly glossy skin, since heavy fruit tends to be juicier. Rolling a lemon firmly on the counter before cutting helps break internal membranes so more juice flows.

Meyer Lemon

The Meyer lemon is widely thought to be a cross between a lemon and another citrus, probably a mandarin or orange. It has a thinner, smoother skin that turns deep yellow with an orange tinge, and its juice is gentler and more floral than that of an ordinary lemon. Cooks often prefer it in desserts, curds and dressings where a softer acidity is welcome. It is less common in shops than the standard lemon and is more delicate in transit.

Yuzu

Yuzu is an aromatic citrus used mainly for its zest and juice rather than eaten out of hand. It is closely associated with East Asian cooking, where the zest flavors broths, dipping sauces and desserts, and the juice is used in seasonings such as ponzu-style sauces. The fruit has a bumpy rind that turns yellow when ripe, many seeds, and little pulp. The aroma is the main attraction: a mix of tart citrus with floral and slightly resinous notes. Fresh fruit can be hard to find outside its growing regions, so bottled juice and dried zest are commonly used.

Citron

The citron is among the oldest citrus types and is an ancestor of other citrus fruits. It is large, lumpy and fragrant, with a very thick pith and little juice. Because the pith is mild rather than intensely bitter in this fruit, the peel is often candied or preserved, and it features in some festive baking. One variety, often called Buddha's hand, has finger-like segments and is used mostly for its fragrance and zest rather than for juice.

Grapefruit and Pomelo

Grapefruit is a large citrus whose flesh can be white, pink or red, while the skin is usually pale yellow. It is tart, slightly bitter and juicy, and is commonly halved and eaten with a spoon or juiced for breakfast. The pomelo is a larger, thicker-skinned citrus with a pale yellow-green rind and mildly sweet segments that are firmer and drier than grapefruit. Peeling a pomelo takes patience because the pith is very thick.

An important safety note: grapefruit and some related citrus can interact with certain medications. The US Food and Drug Administration says that Seville oranges and pomelos may have the same effect as grapefruit juice. If you take any prescription medicine, ask your doctor or pharmacist whether grapefruit, grapefruit juice or related fruit is safe for you. Do not assume it is harmless in any amount.

Yellow citrus at a glance

How do you use zest, pith and segments?

Each part of a citrus fruit behaves differently, so it helps to treat them as separate ingredients.

• Zest is the thin colored outer layer. It contains fragrant oils and almost no bitterness. Remove it with a fine grater or a peeler, avoiding the white layer underneath.
• Pith is the white layer beneath the zest. It is usually bitter and spongy, though in citron it is mild enough to be eaten.
• Segments are the juicy sections. For a clean presentation, cut away peel and pith, then slice between membranes to release neat wedges, a technique often called supreming.
• Juice is best squeezed just before use, since its fresh flavor fades with time.

When you plan to use zest, look for unwaxed fruit if you can, or scrub the skin well under warm water before grating.

How do you store citrus?

Citrus generally keeps longer than many fruits. At cool room temperature it lasts for several days, and in the refrigerator it usually lasts for a couple of weeks or more, depending on the type and starting condition. Keep it in a place with some airflow and check for soft spots or mold, since one affected fruit can spread problems to its neighbors. Citrus fruits do not ripen further once picked, so what you buy is close to what you will get.

Pairing and Cooking Ideas

Citrus matches well with fish, poultry, herbs, honey, vanilla, ginger and chili. A little zest in a cake batter, a squeeze of juice over roasted vegetables, or a few thin slices in a marinade can change a dish significantly. Preserved lemon, made by curing lemons in salt, is a classic ingredient in North African cooking and is used for its softened peel and intense savory-citrus flavor.

As always, if you have a citrus allergy or sensitivity, or use certain medications, check with a qualified professional before adding large amounts to your diet.

Sources and further reading

• USDA FoodData Central: Lemons, raw, without peel: record 167746 (SR Legacy), retrieved through the FoodData Central API: fiber 2.8 g and total sugars 2.5 g per 100 g.
• FDA: Grapefruit juice and some drugs don't mix: the US Food and Drug Administration's consumer update: Seville oranges and pomelos may have the same effect as grapefruit juice, and you should ask your doctor or pharmacist about your medicine.

Frequently asked questions