Coriander (Cilantro)

Leaf, stem and seed are three different ingredients

They come from one plant, and their aromas are unrelated.

• The leaf smells fresh and citrusy, and disappears instantly with heat. It always goes on last, off the heat.
• The stem is more strongly aromatic than the leaf and survives cooking. It is why Thai curry pastes and stir-fries use the stems, and throwing them away is a waste. Chop finely and add early.
• The seed (coriander), toasted, becomes something warm and nutty — the base of Indian and Middle Eastern curry aroma, and it has nothing to do with the leaf.

If a recipe says only "1 tbsp coriander", find out whether it means ground seed or leaf. Swapping them moves the dish to another continent.

The soap thing is not a preference

Between 4 and 14% of people taste soap or detergent in coriander. It comes down to the OR6A2 olfactory receptor gene, which makes certain aldehydes in the plant register as soapy.

So there genuinely are people for whom "you will grow to like it" does not apply. When cooking for guests, serve it on the side.

Using it

• Leaves in the last ten seconds. Pad thai, green curry and shakshuka all take it after the heat is off.
• Stems from the start, as an aromatic base in pastes and stir-fries.
• Seeds toasted, in oil or a dry pan, then ground. A good share of the aroma of chana masala is exactly this (blooming spices).
• Do not mince the leaves — chop coarsely or tear them. Mincing leaves the aroma on the board.

Choosing

• Deep green, not wilted. Yellowing leaves have already lost their scent.
• If any is sold with the roots on, buy that. In Thai cooking the root is a stronger aromatic than the stem.

Storage

• Do not wash it. Trim the stem ends, stand it in a glass of water, cover loosely and refrigerate — over a week. Washed before storing, it goes slimy in three days.
• Wrapped in damp kitchen paper in a sealed box works about as well.
• Freezing does not suit the leaf: it thaws to water, keeping the aroma but losing the form. Blitzed into a paste and frozen, though, it works for cooked dishes (freezing and thawing).
• Whole seeds keep two years, ground about six months.

Substitutes

• Flat-leaf parsley looks similar and tastes nothing like it. In a dish that expected coriander, the gap is still obvious.
• Better to leave it out than to fill in with parsley. The leaf is an aroma, so without it you simply have a dish without that aroma.
• For the seed, cumin plus fennel points in the direction, but is not the same thing.