Dried, shredded coconut is readily available at any supermarket, but starting your recipe with a whole, fresh coconut can improve the flavor dramatically. Opening the large, hairy nuts requires a small investment of effort but yields a gush of mildly sweet coconut water and a quantity of rich, snowy-white flesh. Unfortunately, sometimes the coconut water has a strong smell of alcohol, which indicates that the coconut is spoiled or very old.
It's the Mileage
Coconuts are a tropical nut; in fact, coconut palms are one of the iconic symbols of the tropics. So, if you live in a temperate region, the nuts at your market have come a long way. This is an important consideration since the storage life of a ripened coconut is only two to three months. Much of that time can be spent just in coming to the grocer's, so it's all too easy to get a nut that's past its prime and beginning to ferment. Like most other kinds of fresh produce, picking a good one is mostly about knowing what to look for.
Look It In the Eye
Pick up several coconuts and compare them. The best and freshest will be heavy for their size, so you can quickly narrow your choices. Give each one a shake, and listen to the sound it makes. Good coconuts usually contain lots of coconut water, which slowly evaporates as the nut ages. Finally, look at the three "eyes" at the pointy end of the nut. In a fresh coconut, they'll be about the same color as the rest of the husk. In old coconuts, they begin to soften and darken, sometimes showing visible mold.
No More Tears
One of the surest signs of a damaged or fermenting coconut is the appearance of moisture at one of its eyes, where it can give a disconcerting impression that it's weeping. This means the nut has been punctured or cracked, which allows oxygen and naturally occurring yeasts to enter the nut. The water inside is likely to be fermented, and the flesh spoiled, by these intruders. Often you'll be able to smell alcohol if you hold the affected area close to your nose.
Open It Up
You can improve your chances of getting a good nut by following those basic pointers, but you won't know for sure until you get it home. Opening the nut is easier if you first drain the coconut water, so tap a drainage hole and an air hole into the nut with a sterilized screwdriver or large nail. Pour out the water and smell it. If it's got a strong smell of alcohol, your coconut has fermented and should be discarded. If it smells and tastes sweet, wrap the nut in a clean kitchen towel and crack it sharply with a hammer or the back of a heavy cleaver. It should split easily, giving you access to the sweet, snowy meat.