Coriander leaf vs Coriander seed
The short answer
One plant, two ingredients, and no relationship in flavour whatever. Coriandrum sativum gives leaves that taste of citrus and — for perhaps one person in seven, on a genetic basis — of soap, and seeds that taste warm, nutty and faintly of orange peel. The seed is a background spice used in quantity and the leaf a finishing herb used raw; neither can replace the other and a recipe calling for one and given the other is not a weaker version of the dish but a different one. American English calls the leaf cilantro precisely to keep them apart, which is the one thing that naming convention gets right.
Side by side
| Coriander leaf | Coriander seed | |
|---|---|---|
| Botanical identity | Coriandrum sativum L. | Coriandrum sativum L. |
| Part used | leaf | fruit, seed |
| Origin | The eastern Mediterranean and western Asia, where the species has been cultivated for several thousand years. | The eastern Mediterranean and Near East. |
| Flavour notes | citric, green, cooling, sappy, soapy to some | citrus, warm, sweet, floral, nutty when toasted |
| Heat | Scoville does not apply | Scoville does not apply |
| Flavour | Bright, citric and cooling, with a soapy or metallic edge that some people barely register and others cannot get past. It cuts through fat, chilli and richness better than almost anything else, which is why it is used at the end of dishes from Mexico to Vietnam. | Mild, sweet and lemony with very little bitterness. It is a rounding and bridging spice rather than an assertive one, which is why it appears in so many blends without ever being the thing you taste. |
| Aroma | Powerful, citric and unmistakable, with a green sappy quality underneath. It is one of very few herbs strong enough to identify a cuisine from across a room, and one of very few that a large minority of people actively dislike. | Warm, sweet and distinctly citric, with a light floral and woody character. Toasting brings out a nutty warmth. |
Which should you buy?
Coriander leaf
This is the one profile on SpiceHQ where the buying advice is to skip a form entirely. Dried coriander leaf keeps almost nothing of what makes the herb worth having, and a dish built on its citric lift is better made with a different herb than with a dried version of the right one. Buy fresh, use the stems as well as the leaves, freeze the roots if you find a bunch that has them, and treat the jar of green flakes in the supermarket as a colouring rather than a seasoning.
Coriander seed
Buy whole. Coriander is one of the easiest seeds to grind, one of the most improved by toasting first, and one of the cheapest — so there is no case for the ground product beyond convenience, and the gap in quality is large.
Full detail on coriander leaf and coriander seed, including evidence grades and sources for every claim above.