My Neighbor Gave Me These Strange Black “Nuts”—What Are They and How Do You Eat Them?
At first glance, these strange black, horn-shaped objects look more like something from a fantasy movie than something you would put on a dinner table. 😭
But the good news is that they are edible.
🌰 What Are They?
They appear to be water caltrops, fruits from aquatic plants in the genus Trapa. They are also known by names such as water nuts, buffalo nuts, bat nuts, devil pods, and singhara. (DOI)
The hard black shell protects a white, starchy edible kernel inside.
One important clarification: despite sometimes being called “water chestnuts,” water caltrops are not the same plant as the Chinese water chestnut commonly used in Asian cooking. (Phitip Recipes)
👀 Why Do They Look So Strange?
The unusual horns are simply part of the fruit’s natural structure.
Depending on the species, water caltrops can have two, three, or four pointed projections. The hard shell protects the seed developing inside. (DOI)
The sharp points are not just decorative—they can actually be quite painful if stepped on, so handle them carefully. (clovegarden.com)
🍽️ How Are You Supposed to Eat Them?
The most common approach is to cook them first, then remove the hard shell.
Step 1: Wash Them
Rinse the fruits thoroughly under running water.
Step 2: Cook Them
Water caltrops are traditionally boiled or steamed. Steaming or boiling softens the hard outer shell and cooks the edible kernel inside. (DOI)
For home preparation, a practical method is to simmer them until cooked and tender enough to open safely.
Step 3: Let Them Cool
The shells become extremely hot during cooking, so allow them to cool enough to handle.
Step 4: Crack the Shell
Use a nutcracker or another sturdy kitchen tool to break the hard outer shell.
Be careful with the sharp horns and fragments.
Step 5: Remove the White Kernel
Inside you’ll find a white, starchy kernel. That’s the edible part.
The texture is often compared with a chestnut, although the exact flavor and texture vary by species and preparation. (DOI)
😋 What Do They Taste Like?
Cooked water caltrop kernels are generally described as starchy, mildly sweet, and somewhat nutty, with a texture that can remind people of chestnuts.
They can be eaten as a snack or incorporated into other dishes. (DOI)
In parts of Asia, water caltrops have been eaten for centuries, while archaeological and historical evidence also shows that they were once an important food in parts of Europe. (DOI)
⚠️ One Important Safety Point
Don’t eat an unidentified wild plant simply because it looks like the ones in this photograph.
If these were actually given to you as food, confirm what they are and where they came from before preparing them.
Also, some sources note that raw water caltrop can contain compounds that are reduced or destroyed by cooking, so cooking is the safer preparation method. (clovegarden.com)
If they were harvested from untreated freshwater, proper cleaning and cooking are particularly important.
🌿 A Surprisingly Old Food
Water caltrops aren’t a new food trend. Research published in the Journal of Ecology describes their historical use in Europe and Asia, including being roasted, boiled, eaten as a snack, and dried and ground into flour. (DOI)
So that strange-looking bag from your neighbor may actually contain a food with a very long culinary history.
Final Thoughts
Those scary-looking black “horns” are most likely water caltrops—an aquatic fruit with a hard protective shell and an edible white kernel inside.
Cook them first, let them cool, carefully crack the shell, and eat the white kernel inside. 🌰
And if you’ve never seen them before, I can understand the reaction:
