The water chestnut, also known as Eleocharis dulcis, is a type of aquatic plant cultivated for its edible root. These roots 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 them 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 ones, when they are available, are a completely different experience. The crunchy texture may be similar in both, but fresh roots are sweeter, with layers of flavor that 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. They 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 they 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 that will be retained through cooking, along with the crunchy texture. Unlike many vegetables that soften as they are heated, these roots 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 inside will be bright white. Fresh roots can be stored under refrigeration in water for up to one week before use. Canned ones can be kept in a cool dry place until they are opened, after which they should be rinsed and used within a few days.