The water chestnut, also known as Eleocharis dulcis, is a type of aquatic plant cultivated for its edible root. Water chestnuts are a staple of Chinese and Asian cuisine, thanks to their delicate flavor and crunchy texture. They are also used in fusion cuisine, and sometimes appear in surprising places. Asian markets stock water chestnuts in several forms, and some grocery stores carry them as well, depending on demand.

Many Western consumers are only familiar with canned water chestnuts. Fresh water chestnuts, when they are available, are a completely different experience. The crunchy texture may be similar in both, but fresh water chestnuts are sweeter, with layers of flavor which are obscured during the canning process. The flesh of the vegetable also has a slightly different texture, with fresh water chestnuts being more brittle and prone to shattering, rather than slightly slimy like their canned cousins. Water chestnuts can also be found in pickled form at some markets, and the flesh is sometimes ground to make flour. The flour can be somewhat expensive, but it is well suited to certain Asian dishes.

The preferred growth environment for water chestnuts is stagnant or slow moving water. They tend to prefer ponds and lakes, although they will also grow in sluggish streams. The roots require about seven months to mature, and the plants prefer to be warm, so water chestnuts are almost exclusively cultivated in semi-tropical environments. The plants are classified as sedges, thrusting grasslike leaves above the water while rooting in the mud below.

In cooking, water chestnuts are used in a lot of dishes to add texture and flavor. They have a faintly sweet flavor which will be retained through cooking, along with the crunchy texture. Unlike many vegetables which soften as they are heated, water chestnuts stay firm, adding a crunchy mouthfeel to the dishes they are included in. In addition to Asian foods, water chestnuts go well with stuffings and in salads, and can be eaten raw or cooked.

When selecting fresh water chestnuts, if they are available, look for plump specimens without any sign of wrinkling. The outer skin should be dark brown and lustrous, and when cut open, the water chestnuts will be bright white. Fresh water chestnuts can be stored under refrigeration in water for up to one week before use. Canned water chestnuts can be kept in a cool dry place until they are opened, after which they should be rinsed and used within a few days.