I've learned the hard way that if you have a recipe that calls for coconut milk, you can't swap in coconut water. Even though both have the word coconut in the name, coconut water and coconut milk are two very different liquids with very different consistencies and purposes. So what is the difference between coconut water and coconut milk—and, while we're at it, what is coconut cream, exactly?
To learn more, I spoke with an expert: Arthur Gallego, global director of corporate communications at Vita Coco, which makes coconut water, coconut milk, and coconut oil. It turns out that even though all three of these liquids come from a coconut and therefore taste coconut-y, that's about where the similarities end.
"Coconut water is the water from inside a younger green coconut," Gallego says. "Those coconuts are harvested at roughly six to nine months." Coconut water is naturally occurring; if you pick up a young coconut and gently shake it, you'll be able to hear the water sloshing around inside. All you have to do to get the liquid is to chop off the top of a young, green coconut and pour out the coconut water. That's basically what you're drinking when you drink a bottle of coconut water—though depending on what type of coconut water you have, there may be some additives, usually either for additional flavor (like pineapple-flavored coconut water) or to stabilize the color.
Unlike coconut water, coconut milk isn't something you can harvest directly from the coconut. "[Coconut milk] is produced from the coconut meat, which is processed and taken out of the coconut and then filtered and liquefied," Gallego says. But making coconut milk is fairly straightforward. You take the meat from the inside of a more mature, brown coconut and basically shred and purée it until it's cream-like in texture. "That cream is then diluted with water or coconut water," Gallego says, though in the case of Vita Coco coconut milk, the coconut cream is emulsified with both coconut water and filtered water.
The result of this process is a drink that's close in consistency to whole milk and can be used as a plant-based dairy substitute in your coffee or bowl of cereal. You can also use it as a dairy substitute in baked goods, but since the pH level is slightly different than that of conventional milk, you should test it out and adjust your recipe accordingly.
"The fattiest is coconut cream," Gallego says. "That's usually used for baking, and it has a particular consistency you would want in baking." To give you a sense of the texture and weight, you can use coconut cream in lieu of heavy or whipping cream to make vegan whipped cream.
Since coconut cream is basically an ingredient of coconut water, the way you make it is to let coconut milk sit until it separates. As Harold McGee writes in On Food and Cooking: The Science and Lore of the Kitchen, "Left to stand for an hour, this milk separates into a fat-rich cream layer and a thin 'skim' layer." Spoon that fatty layer off the top, and just like that, you've got coconut cream. (Don't confuse it with cream of coconut, though; that's actually coconut cream with sugar, not straight-up coconut cream.)