When properly cooked, the flesh can have a texture somewhat reminiscent of a chestnut.

It can be mildly sweet, nutty, earthy, or starchy depending on the species and preparation.

That's why these fruits have traditionally been used in various dishes.

The contrast is striking:

Outside: dark, hard, and covered in horns.

Inside: pale, starchy, and edible.

It is one of those foods that looks completely different before and after preparation.

Are They Actually Related to Chestnuts?

Despite the name "water chestnut," water caltrops are not the same thing as the familiar Chinese water chestnut (Eleocharis dulcis).

This is an important distinction.

Chinese water chestnuts are aquatic sedge plants that produce small, rounded underground corms.

Water caltrops are fruits produced by plants in the genus Trapa.

The two foods can both be eaten and have somewhat starchy textures, but botanically they are quite different.

So if someone calls these "water chestnuts," the name can be confusing.

How Do People Eat Them?

Traditionally, the edible interior is obtained by cooking the fruit and then removing the hard shell.

Preparation varies depending on the region and species.

One common approach is to:

1. Wash the fruits thoroughly.

2. Cook them by boiling or steaming.

3. Allow them to cool enough to handle safely.

4. Crack or cut away the hard outer shell.

5. Remove the edible kernel.

6. Eat the cooked kernel on its own or incorporate it into another dish.

The exact cooking time can vary according to size and species, so it's best to use a reliable recipe specific to the type you have.

Why Cooking Matters

This is probably the most important part of the story.

Because water caltrops grow in freshwater environments, eating them raw isn't a good idea.

Freshwater plants and aquatic produce can become contaminated with microorganisms or parasites from the environment.

One parasite of particular concern in some regions is Fasciolopsis buski, a foodborne intestinal fluke associated with raw or inadequately cooked aquatic plants.

This doesn't mean every water caltrop is contaminated.

It means that raw freshwater plant foods can carry risks that cooking helps reduce.

For that reason, traditionally prepared water caltrops are generally cooked thoroughly before consumption.

Don't Treat Them Like a Normal Fresh Fruit

If you receive a bag of these from a neighbor, don't assume they're ready to eat simply because they look clean.

The safest approach is to first establish: