Drinking a coconut comes down to getting through the shell to the water inside, and the technique depends on whether you have a young green coconut or a mature brown one. A young coconut holds roughly 250 mL (about 8.8 oz) of water in a smaller immature fruit, while larger young coconuts at the 5-6 month stage can contain nearly 700 mL. Here’s how to get to it.
Young Coconuts vs. Mature Coconuts
Young green coconuts are the ones you’ll see at Thai restaurants, smoothie shops, and Asian grocery stores. They’re usually sold with the green husk trimmed into a white, dome-shaped point. The water inside is sweeter, with higher levels of fructose and glucose, and tastes lighter and more refreshing. Peak sweetness hits between 7 and 9 months of age, when sugar content is at its highest.
Mature brown coconuts, the hairy ones at most supermarkets, hold roughly half as much water (around 330 mL). The flavor is less sweet overall, though the water contains more potassium, magnesium, calcium, and protein. It also has a slightly more neutral taste because the natural plant compounds that give young coconut water its bright, floral quality decrease as the fruit ages.
If your goal is simply to drink coconut water, a young coconut gives you more liquid and a sweeter flavor. A mature coconut is better when you want both the water and the thick white meat inside.
How to Open a Young Coconut
Place the coconut upright on a non-slip cutting board on a hard, stable surface. You’ll notice a ridge near the pointed top. Starting about an inch above that ridge, use a sharp cleaver or heavy chef’s knife to shave away the white husk, angling your cuts toward the tip until you expose the harder inner shell at the crown. Once the crown is exposed, strike it firmly with the heel of the cleaver to crack through. You can then pry open a hole or pop off the top entirely.
If swinging a cleaver at a coconut sounds intimidating, you’re not alone. Dedicated coconut opening tools exist, typically a pointed metal spike with a handle that you hammer or twist into the soft spot at the top. These are safer and work well, especially if you open coconuts regularly. For occasional use at home, a cleaver you already own does the job, but the margin for error is smaller. Work on a stable surface, keep your non-dominant hand well clear of the blade, and let the weight of the knife do the cutting.
Once you’ve made an opening, stick a straw in and drink directly from the shell, or pour the water into a glass.
How to Open a Mature Brown Coconut
A mature coconut has three dark “eyes” at one end, small indentations arranged in a triangle. One of them is softer than the other two. Press a clean screwdriver, metal skewer, or sharp paring knife into each eye until you find the soft one, then push through to create a hole. Widen a second eye the same way so air can flow in and the water drains freely.
Hold the coconut over a glass and let the water pour out, or flip it upside down and give it a minute. You’ll get a smaller yield than a young coconut, and the flavor will be milder and slightly more mineral. If you want to crack the whole coconut open for the meat, wrap it in a towel and tap it firmly around its equator with a hammer or the back of a heavy knife until it splits.
How to Tell If Coconut Water Is Safe to Drink
Fresh coconut water should smell clean and mildly sweet, with no sour or fermented odor. If it smells off, tastes foul, or the interior of the coconut looks slimy or rotten, discard it immediately. Spoiled coconut water can harbor dangerous toxins. In one documented case published in Emerging Infectious Diseases, a man who opened a coconut and found slimy, rotten-looking flesh became seriously ill after swallowing even a small amount of the foul-tasting water.
Before opening, give the coconut a shake. You should hear water sloshing inside. A mature coconut with no sloshing sound may be dried out or spoiled. For young coconuts, check that the husk isn’t moldy and the bottom isn’t soft or leaking.
You may notice fresh coconut water turning pink after you open it. This is a natural reaction that happens when antioxidant compounds in the water are exposed to air. It’s harmless and occurs most often in young coconut water, which has higher levels of these compounds. Pink coconut water is safe to drink as long as it still smells and tastes normal.
Storing Fresh Coconut Water
If you don’t finish the water right away, transfer it to a sealed container and refrigerate it. Fresh coconut water keeps for about 1 to 3 days in the fridge. Commercial coconut water that’s been opened lasts slightly longer, around 3 to 5 days, because pasteurization slows spoilage. Either way, taste it before drinking if it’s been sitting for more than a day. Once it develops a sour or fizzy quality, it’s started to ferment and should be tossed.
Coconut Water for Hydration
Coconut water is often marketed as a natural sports drink, and there’s some truth to that. A study in the Journal of the International Society of Sports Nutrition compared coconut water to a commercial carbohydrate-electrolyte sport drink in exercise-trained men who had lost about 2% of their body mass through sweating. Both beverages restored hydration equally well, with no significant differences in fluid retention, blood concentration, or exercise performance afterward.
Coconut water is naturally rich in potassium but relatively low in sodium. This makes it a fine everyday hydration choice, but if you’re rehydrating after intense, prolonged exercise where you’ve lost a lot of salt through sweat, a drink with more sodium may work better.
Who Should Be Careful With Coconut Water
The potassium content in coconut water is worth paying attention to if you have kidney problems. Mature coconut water contains roughly 350 mg of potassium per 100 mL, and young coconut water around 220 mg per 100 mL. Healthy kidneys handle this easily, but kidneys that aren’t filtering properly can allow potassium to build up in the blood to dangerous levels. Case reports published by the American Heart Association have documented severe, life-threatening spikes in blood potassium from drinking large amounts of coconut water. If you have kidney disease or take medications that raise potassium levels, keep your intake moderate or check with your care team first.