Water caltrop

Trapa natans · Vegetable

40 pairings

The water caltrop (Trapa natans) is the starchy nut of a floating aquatic plant, encased in a hard, glossy-black shell drawn out into two or four sharp horns that gave it its name. Boiled and shelled, the white kernel tastes mild, sweet and starchy — like a cross between a chestnut and a water chestnut — and is a staple snack and ingredient across East and South Asia.

Picking a good onedrag

Taut and glossy, dead weight in the handLight and rattling, furred at the horns

Market freshThe standard nut: boil in the shell, then peel for snacking, braises and stir-fries. Judge colour as variety and age, not freshness — green, red and purple all sell fresh, and a black shell just means an older, harder one.Everyday best

ShellDuller sheen, skin sound, no cracks anywhere

Weight in the handStill solid, no give under the thumb

Horns and stalk scarHorns intact, scar dry and slightly shrunk

Smell at the basketAlmost nothing, damp and neutral

What to look for, from taut and glossy, dead weight in the hand to light and rattling, furred at the horns.

Preparing