Fingerroot

• krachaiกระชาย

  Thai

  The everyday Thai name, and the one to use in a Thai grocer. English recipe translations frequently render it as "lesser galangal", which is a different plant, or as ginger, which is a different genus.

• temu kunci

  Indonesian

  Literally "key root", from the shape — the same image English reaches for in "Chinese keys". Indonesian usage is largely in soups and vegetable dishes rather than in curries.

• ao chun jiang

  Mandarin

  Chinese-language usage is chiefly medicinal rather than culinary, and a Chinese herbal shop may sell a dried grade that is not what a Thai recipe means.

Peppery, earthy and distinctly bitter, with a lingering medicinal finish and no sweetness. The bitterness is the point: in a jungle curry, which has no coconut milk to soften anything, fingerroot supplies a bite that carries the dish, and in the Thai fish curries it cuts the oiliness of the fish in a way ginger cannot.

Peppery and green with a camphorous, faintly medicinal edge, and much less of the citrus-and-pine sharpness that leads in galangal. It smells more like a root and less like a perfume than its relatives.

Pale yellow-brown skin over a pale yellow interior, considerably lighter than turmeric and darker than young galangal.

Firm and crisp when fresh, less fibrous than galangal and less juicy than ginger. It slices into fine julienne cleanly, which is how it usually goes into a curry.

Scrape the thin skin rather than peeling thickly — much of the aroma is just beneath it. For a curry, cut the fingers into fine julienne along their length and add them to the simmering dish, where they stay firm and are eaten; for a paste, pound them with the other aromatics. Fry the paste only briefly before the liquid goes in, because prolonged frying turns the bitterness harsh. Use more than instinct suggests if you are used to galangal: fingerroot is less aromatic and more bitter, and a jungle curry is supposed to taste of it.

The aromatic of Thai curries that contain no coconut milk, where its bitterness carries a dish that has no fat to soften it — jungle curry above all, and the fish curries and nam ya. It is julienned into the dish and eaten rather than infused and removed, which distinguishes it from galangal. In Indonesia it goes into clear vegetable soups in a lighter role. In Thailand the young shoots are also eaten raw with chilli dips, which no other rhizome in this catalogue is.

• grinding — Pounded into a curry paste with the other aromatics, which is the dominant use. The fibres break down readily, unlike galangal, so it does not leave the thread-like residue galangal does.
• frying — Fried in the paste at the start of a curry. Brief frying rounds the raw bitterness; prolonged frying makes it harsh.
• boiling — Added as fine julienne to jungle curry and to fish curries and simmered in the dish, where it stays firm and is eaten rather than removed. This is one of the few rhizomes in the catalogue routinely consumed rather than infused and discarded.

Snap a finger. Fresh fingerroot breaks crisply and smells peppery and camphorous immediately; a rhizome that bends without snapping has lost water and will be woody and bitter without the aroma.

• Fingers bending rather than snapping
• Soft or darkened cut ends
• A sour or fermented smell rather than a peppery one
• Visible mould, which for a fresh rhizome means discarding it

• Moisture loss and shrivelling at room temperature
• Mould at the cut ends in humid or sealed wet storage

Neither, in the usual sense: this is a fresh rhizome and the real choice is fresh, frozen or brined. Buy it fresh where that is possible and frozen where it is not — frozen fingerroot julienned straight from the freezer is close to the fresh article, which is not true of the dried and ground product. Brined fingerroot from a jar will get a curry made and will not taste like the dish it came from.

• Firm fingers that snap rather than bend.
• Pale, unblemished cut ends with no softness or darkening.
• A clear peppery, camphorous smell at a fresh break.
• Frozen in preference to brined where fresh is unavailable — frozen keeps the character, brined does not.
• Sold as krachai or temu kunci rather than as "lesser galangal", which usually means the seller is guessing.

Zingiberaceae

A low herbaceous perennial with broad green leaves rising from a short central rhizome, from which hangs a distinctive bundle of slender, pale yellow-brown tubers a few centimetres long. The bundle is the identifying feature and the source of every one of its names.

Mainland and island Southeast Asia, with cultivation across Thailand, Indonesia, Malaysia, Cambodia and southern China.

• TH — origin. The largest culinary user and the source of most of what is exported fresh and frozen.
• ID — major producer
• MY — notable producer
• KH — notable producer

Lifted whole with the finger cluster intact, washed and sold fresh. Freezing and brining are the usual routes for export; drying is a distant third and is mainly for the medicinal trade.

1. Lifting the cluster — Dug when the leaves die back. The rhizome grows as a central knob with slender fingers radiating downward, and the fingers are the part used — which is where the English name comes from.
2. Washing and trimming — Washed and the fingers separated from the mother rhizome, which is coarser and more fibrous and is usually replanted rather than sold.
3. Using fresh, julienned — Cut into fine matchsticks rather than grated or pounded, which is how Thai and Cambodian cooking almost always uses it.Why: The texture is firmer and less fibrous than ginger or galangal, so it holds its shape in a curry and is eaten rather than strained out — a use neither of the others supports.
4. Brining or freezing — Sold brined in jars and frozen whole. Both keep considerably more of the character than drying does.
5. Slicing and drying — Dried into hard pale slices, and the least satisfactory of its forms.Why: Fingerroot loses more to drying than kencur does, and the dried product is a weak substitute for the fresh rather than a different ingredient with its own uses. Where a recipe specifies krachai, frozen is a much better answer than dried.

Not an adulteration problem so much as a labelling one: the product sold in Western shops as fingerroot is usually frozen or brined rather than fresh, and jars labelled "krachai" in brine are a materially different ingredient from the fresh rhizome — softer, saltier and much less aromatic. Substitution with young galangal or with ginger happens at the retail end under English names.

Grown from rhizome pieces and lifted after a growing season, much as ginger and turmeric are. It is a common home-garden plant across its range rather than exclusively a field crop.

Wet tropical, with partial shade and rich moist soil. It suits smallholder and garden cultivation and is widely grown domestically as well as commercially.

Fingerroot has been used across Southeast Asia in both cooking and herbal practice for a long time, and unlike the spices of the maritime trade it never became an object of long-distance commerce — it is a fresh rhizome with a short life, which rules out the routes that carried pepper and cloves. Its distribution today still broadly matches where it grows and where its diaspora went.

A regional fresh-produce trade rather than a spice trade, with frozen and brined product reaching Southeast Asian grocers abroad. Volumes are not separately reported in the international statistics.

Used across Thai, Indonesian and Chinese herbal traditions, chiefly for digestive complaints. Recorded as tradition; SpiceHQ makes no health claim and holds no clinical source assessing it.