Water chestnuts - where would Chinese food be without them? The knobby vegetable with the papery brown skin is a staple in Chinese cooking. The water chestnut is actually not a nut at all, but an aquatic vegetable that grows in marshes. The name "water chestnut" comes from the fact that it resembles a chestnut in shape and coloring. Indigenous to Southeast Asia, it has been cultivated in China since ancient times.
Water chestnuts require a long frost-free growing season (7 months) which means that they are only grown in semi-tropical areas, including a few States such as California and Florida. Fresh water chestnuts are available year-round in Asian markets, either packaged or in bins. Unless you live in an area where they are grown locally, they are generally not available in local groceries and supermarkets. Canned water chestnuts are available year round at most groceries and supermarkets.
The scientific name for Chinese water chestnuts is Eleocharis dulcis, coming from the Greek Eleos (marsh) and Charis (grace). Chinese herbalists believe water chestnuts can help sweeten the breath.
How to Select Water Chestnuts
When choosing fresh water chestnuts, look for firm ones with an unwrinkled skin and no soft spots - otherwise when you peel the water chestnut you may find it has softened and turned mushy.
Generally, it's best to buy a few more chestnuts than needed, just in case a few have spoiled.
Unpeeled, fresh water chestnuts will keep for up to two weeks in a plastic bag in the refrigerator. Prior to cooking, you'll need to cut off the top and peel the skin. If you want to peel them ahead of time, that's fine, but be sure to store them in cold water in the refrigerator, with the water changed daily.
Store canned water chestnuts in a cool dry place and use within a year. Once opened, store the water chestnuts in a sealed container in the refrigerator and use within three days.
How to Prepare Water Chestnuts
As mentioned above, fresh water chestnuts need to be peeled and the top cut off before using. Before using canned water chestnuts, rinse them under warm running water to remove any "tinny" taste. Water chestnuts are frequently added to stir-fries, stuffings, and dumpling fillings for extra texture and a sweet flavor.
Fresh water chestnuts are worth searching for, as they have a sweeter flavor and are quite crisp. However, canned water chestnuts can be used as a substitute, particularly if they are being added mainly for texture. Definitely try to use fresh water chestnuts in appetizers such as Bacon Wrapped Water Chestnuts, or any other dish where the water chestnut is the main ingredient.
Nutrition of Water Chestnuts
Nutritionally, water chestnuts are a good source of potassium and fiber. They are low in sodium, and fat is virtually non-existent. One cup of water chestnut slices contains about 130 calories. Low carb dieters, beware: water chestnuts are high in carbohydrates. You may try replacing them with low carb bamboo shoots, but the flavor will vary.
It's difficult to find another vegetable combining the sweet flavor and crunchy texture of water chestnuts. Jicama is often recommended for texture, but the flavor just isn't the same. With a pork dish, try substituting apple slices.