What's Coriander, and Why Does It Brighten Heavy Food?

Coriander seed tastes citrusy, warm and gently nutty, with no chile heat. It brightens heavy food from inside the spice base, which is why dal, curries, roasted roots and pickles use it so often, usually beside cumin.

What is coriander spice?

Coriander spice is the dried fruit of Coriandrum sativum, the same plant whose leaves are sold as cilantro. Each small round "seed" is really a whole fruit that splits into two halves, and each half holds one true seed.

The plant belongs to the Apiaceae, the carrot family, which also gives the kitchen cumin, fennel, caraway, dill and parsley.

Plant

Coriandrum sativum, family Apiaceae

Part used

The dried ripe fruit, sold as coriander seed

Native range

The Mediterranean Basin

Main aroma compound

Linalool, the citrus-floral compound that dominates the seed oil

Largest producer

India, which also uses most of its own crop

That family link explains why fennel and caraway can stand in for coriander in some dishes. They share the same husk-and-oil build, but each carries a different lead aroma.

Coriander is also one of the oldest spices on record. Dried coriander seeds turned up in a Pre-Pottery Neolithic layer of the Nahal Hemar cave in Israel, and about half a liter of seed was placed in Tutankhamun's tomb.

Because coriander does not grow wild in Egypt, that tomb find suggests Egyptians were already cultivating it.

The name carries a clue about ripeness. It probably comes from the Greek koris, a bedbug, after the rank smell of the green plant and its unripe fruit.

The oil changes as the fruit matures. In a study of coriander fruit picked at three stages, linalool rose from about 11 percent of the oil in unripe fruit to about 88 percent in fully mature fruit.

The citrus flavor cooks expect means the fruit has to ripen on the plant before harvest. Fresh green seed picked early from a bolting cilantro plant is a separate ingredient, closer to the leaf, and cooks use it raw in dressings and quick pickles.

Is coriander the same as cilantro?

Coriander and cilantro come from one plant, yet they are different parts and taste nothing alike.

In the United States and Canada the fresh leaf is sold as cilantro and the dried fruit as coriander. In Britain, Australia and India the leaf is called coriander too, so a recipe from there asking for a handful of chopped coriander means the herb.

The soapy taste some people notice belongs to the leaf alone. Fresh leaves are led by aldehydes such as 2-decenal and 2-dodecenal, and people with a common variant near the OR6A2 smell-receptor gene tend to read those compounds as soap.

The dried seed is dominated by different compounds, which means many people who cannot eat cilantro cook happily with ground coriander.

The two are never interchangeable in a recipe. A teaspoon of ground seed gives a warm background note, and fresh cilantro gives a raw green finish.

What does coriander taste like?

The flavor sits somewhere between orange peel and toasted nuts, with a floral edge. Many cooks describe it as lemony, and that impression comes from one molecule.

Linalool makes up roughly 60 to 80 percent of the seed's essential oil, which is why coriander reads as one clear note rather than a crowd of them.

That citrus note lifts heavy food without adding acid. Lentils, turmeric-rich curries, roasted roots and fatty meat all taste clearer when coriander sits in the spice base, because the seed brightens them from inside rather than on top.

The pattern in that table repeats in every row. Coriander rarely supplies the main flavor, but leaving it out makes the dish taste heavier than it should.

Where the seed was grown changes that citrus note too, because oil content varies several times over from one seed type to another.

What types of coriander seed can you buy?

Most coriander on a shelf belongs to one of two botanical groups. The group decides how much aroma each seed can hold.

Small-fruited coriander from cooler climates holds several times more essential oil than the large, thick-husked fruit grown in India, Morocco and other warm regions.

Indian traders grade coriander largely by color. Seed dried in partial shade keeps a green tint and more of its aroma, so it trades above every other grade.

Seed left too long in the sun turns brown and sells as Badami. It makes up about half of India's crop, and most of it goes to spice grinders.

Color alone cannot promise aroma, because a green seed that sat in a warm store for months can smell weaker than fresh brown seed.

Russia and Ukraine are among the largest growers outside India, and much of the small-fruited crop from temperate regions goes into coriander oil.

Should you buy whole or ground coriander?

Whole seed keeps its aroma far longer than ground coriander. As with most whole and ground spices, grinding exposes the oil to air, so the citrus top note fades long before the powder looks old.

The thin, partly hollow husk makes coriander one of the easiest seeds to grind at home, which means buying whole costs very little extra effort.

How fine you grind it then decides where the flavor lands.

Fine powder suits a sauce because the aroma has to spread evenly through liquid. A coarse crack keeps texture on the surface of a rub, where fine powder would scorch or turn pasty.

That slight thickening in a sauce comes from the husk, which USDA data put at about 42 grams of fiber per 100 grams of seed.

Blade grinders often leave coriander uneven. The light husk fragments bounce above the blade instead of meeting it, so a mortar or a burr mill gives a more even result than pulsing for longer.

How do you toast and cook coriander?

Heat changes coriander more gently than it changes cumin, but whole seed and powder need different treatment. Whole seed can take a dry pan, and ground coriander needs fat or liquid around it.

Toasting whole seed before grinding rounds the citrus note and adds a nutty depth.

1. Heat the panSet a dry, heavy pan over medium heat and add the whole seeds in a single layer.
2. ToastShake the pan often as the seeds darken slightly and begin to pop, usually within a couple of minutes.
3. Judge by smellStop when the pan smells of orange peel and warm nuts, before any smoky note appears.
4. CoolTip the seeds onto a plate and let them cool fully, because warm seed clumps in the grinder.
5. GrindGrind only as much as the dish needs.

Toasting comes before grinding because powder has no husk left to shield its oil. Ground coriander dropped into a dry, hot pan scorches within seconds and turns flat and bitter.

Powder does better blooming in oil after onion or tomato has softened. Their moisture keeps the pan below scorching heat.

Long, wet cooking is the most forgiving route of all. In dal, soup or a braise, ground coriander simmered in the liquid loses its raw, chalky edge and spreads through the starch.

Untoasted seed has a place when a raw yogurt sauce or salad needs the cleaner citrus that toasting pushes toward nuttiness.

How does coriander work with cumin?

Cumin and coriander appear together so often because they pull a dish in opposite directions. Ground cumin adds earthy depth, and coriander keeps that depth from turning muddy.

The ratio between cumin and coriander shapes a dish more than either spice does alone.

North Indian cooking often builds on dhania-jeera, a mix of about two parts coriander to one part cumin. Mexican and Tex-Mex cooking often uses cumin with no coriander at all, which is part of why chili tastes so strongly of one spice.

A dish that tastes heavy and flat after plenty of cumin usually needs coriander rather than more cumin. More of the earthy spice cannot add the lift that is missing.

Earthy turmeric benefits in the same way, because coriander rounds off its bitter edge in a curry base.

Where is coriander used?

Few spice blends from India, the Middle East or North Africa leave coriander out.

Its role changes with the cuisine. The same seed can be the bulk of a curry powder or a faint citrus note in gin, which means one jar serves very different dishes.

• Indian cookingGround coriander is the bulk of most curry powder and a standard part of garam masala.
• Middle Eastern and North African blendsEgyptian dukkah, baharat and ras el hanout all use it, usually beside cumin.
• Ethiopian cookingBerbere spice pairs coriander with chile, fenugreek and other warm spices.
• PicklingWhole seed is a standard part of pickling spice for cucumbers and brines.
• Sausages and breadGerman sausages, South African boerewors and rye breads use it for a mild citrus warmth.
• Russian and Georgian cookingBorodinsky rye bread is topped with whole seed, and Georgian khmeli suneli blends ground coriander with blue fenugreek and dried herbs.
• DrinksBelgian witbier is brewed with coriander and orange peel, and coriander is the most common gin botanical after juniper.
• Thai cookingCurry pastes use the root and the seed, and the leaf goes on at the end.

Most of those uses rely on the seed for volume and lift rather than for a signature flavor. Curry powder can be up to 40 percent coriander, yet few people would say it tastes of coriander.

Where coriander does lead, as in witbier or a coriander-crusted fish, it needs a base with enough fat, starch or acid to hold it.

How much coriander should you use?

Recipes measure coriander by the teaspoon rather than the pinch. Its flavor is mild enough that a dish for four often takes one to two teaspoons of ground seed.

Wet dishes can take the top of each range because liquid hydrates the powder and spreads it evenly.

Some recipes list whole seed when only powder is in the cupboard. Published conversions for 1 teaspoon of whole seed run from 3/4 to 1 1/4 teaspoons of ground coriander.

The spread comes from air, because round seeds leave gaps in a measuring spoon.

A level spoon of powder for a level spoon of seed sits in the middle of that range. Tasting near the end of cooking settles the rest.

Too much coriander tastes perfumed and floral rather than hot. Because the failure is gentle, it often goes unnoticed until the dish is finished.

More of the unseasoned base is the cleanest fix, whether that means stock, tomato, lentils or rice. A squeeze of lemon also pulls the perfume back, while more cumin only makes the dish heavier.

What can you substitute for coriander?

Every substitute misses part of coriander's flavor, so the best coriander seed substitute depends on the job the seed was doing in the recipe.

The cumin and fennel pair comes closest in most savory dishes. Fennel seed supplies sweetness and lift, and cumin supplies the warmth coriander usually sits beside.

Lemon zest helps when the missing flavor is brightness rather than bulk. A little zest stirred in near the end restores some of the citrus note that none of the seed swaps carry.

Fresh cilantro cannot replace the seed, because the leaf tastes green and sharp rather than warm.

Is coriander safe for everyone?

Cooking amounts of coriander are an everyday food for most people. Two limits are worth knowing, a rare allergy and a small risk in raw powder.

Spice allergy is uncommon. In one French series of 589 patients, spices accounted for about 2 percent of food allergies.

When it does occur, coriander often travels with its relatives. People sensitized to birch or mugwort pollen can react to coriander, cumin, fennel and anise together, a pattern allergists call celery-mugwort-spice syndrome.

That cross-reaction means a person with a known celery or fennel allergy has good reason to ask an allergist about coriander before cooking with it.

Imported coriander has also been a Salmonella concern. In FDA sampling from 2007 to 2009, about 15 percent of coriander shipments offered for entry tested positive, with ground and cracked seed contaminated more often than whole seed.

Packaged spice on store shelves tested far cleaner. In an FDA retail survey from 2013 to 2015, about 0.56 percent of ground coriander samples carried Salmonella.

That remaining risk matters most when powder goes onto food with no further cooking, such as a raita or a chaat topping.

A spice simmered in a dal or curry is heated well past the point that kills Salmonella.

How do you buy and store coriander?

Good coriander seed smells clearly of orange peel the moment it is cracked. Old seed and old powder smell of little more than dust or cardboard, and a larger dose cannot bring the missing citrus back.

• Whole seedTan, light brown or faintly green, even in size, and fragrant when one is crushed between the fingers.
• Ground corianderSold in small jars by shops with fast turnover, since powder fades first.
• Named originIndia or Morocco on the label tells you which seed type you are buying.
• PriceCoriander is cheap, so replacing a tired jar costs less than cooking with it.

Heat, light and air all speed aroma loss. A jar stored sealed in a closed cupboard keeps coriander better than an open rack beside the stove.

The smell test is more reliable than the date on the jar, because storage conditions change how fast the oil fades.