Here's how to open and drink a coconut with a knife. Most people use a machete, but if you're traveling light and don't have one (me most of the time) it's good to know how to do it with a knife (or a sharp stick).
For more ways to eat a coconut, try
Coconut Milk and
Eat a Sprouted Coconut
Coconut milk is different from juice. Milk is made from the meat of the coconut.
Even very young green coconuts are full of "coconut water" a.k.a. coconut juice.
Before I knew anything I'd try to open the husk with a hammer, hatchet, banging on the ground.
It was a huge pain in the neck, and by the time I got them open all the juice had leaked out. I thought they were some kind of ornamental palm tree with hollow coconuts. Wrong. As far as I know there's no such thing.
Older coconuts have a brown outer husk and a hard shell inside that. Inside the coconut shell is a half-inch or so of white meat and coconut juice inside that. If the brown coconut sits on the ground for a long time the juice can go sour even if there's no visible break in the shell. If the brown coconut has floated in salt water and washed up on a beach, there's a good chance there's sweet juice in it and good meat too. In between the baby coconut and brown dry stages are intermediate ones. Usually the juice gets sweeter as the nut gets older.
There are many varieties of coconut, some are bred for drinking, some for making rope, some for meat, etc.
Photos by Star
Step 1: Pick a Coconut
The magic trick to picking coconuts is to twist them off. Just keep spinning your chosen coconut and it'll fall right off. It's very hard to just pull off a coconut with a straight pull. Especially if you're way up in a swaying tree. They do randomly fall off by themselves, but it's unlikely the coconut you choose will be ready to come right off. So just spin it until it falls.
Speaking of falling coconuts, falling coconuts kill a few people per year. If you spend much time near coconut trees you'll get used to hearing the "thud" sound of falling coconuts at night. They do that natually, also coconut crabs and climbing rats chew them off in hopes that they'll break when they hit. If it doesn't break they'll pick one on the ground and spend however long it takes to gnaw a hole in it, a triumph of patience. Shake and examine any nuts you find on the ground to make sure it still has juice and hasn't been opened by some critter already. Most places the critters are pretty scarce, and the nuts on the ground are good.
If you can't find a coconut on the ground, there will be some in the trees. Fortunately the ones lower down will be more mature than the ones higher up.
Tree climbing is a specialty in most places I've been. No matter how "native" or athletic looking the people are, there's usually only one guy who does all the climbing. So don't feel bad if you can't just instantly scamper up a tree. Consider using a ladder, a pruning saw on a pole, or tying a machete or knife to a pole at right angles to cut the stems. I find that cutting up with the pole knife works better than pulling down, and the pruning saw is good for bringing down a whole bunch of them. A mast from a small boat or windsurfer makes a good pole knife if you have a strip of innertube to lash the handle of the knife across it at the top.
Be very cautious about climbing trees. Falls are pretty common even among expert climbers. Falls kill, swell your brain causing brain damage, and break bones. Hospitals are usually far from your coconut trees and sources of infection are abundant. When you get to the top, don't trust the lower branches, they may be ready to shed. Scorpions and other critters like to rest on the base of the branch, and might attack when your hand invades their home.
Step 2: Where Is the Nut?
Coconuts come in all shapes and sizes. The thing you see on the tree is the outer husk. There's a smaller hard round nut growing inside that. Depending on the breed, the nut might be in the middle, down by the lower tip, or up next to the stem. You can get some idea of where it is by shaking it and listening to the liquid splash around. Or you can just butcher a nut and find out. Usually all the nuts in a region will have the nut placed the same.
Step 3: Shirtless - Avoid Stains
Take your shirt off. Coconut juice will stain your shirt yellow/brown. It's time-delayed invisible ink, a stealth stain that shows up later. Sap from the coconut does the same thing. Flex your abs. Living on an island, playing in the water and eating coconuts do great things for your bod.
Step 4: Initial Incision
Stab the side of the coconut. This is easier than it sounds, especially if it's a young coconut. Probably a little bit of juice will squirt out. The coconut is under pressure.
Make two more stabs to make a triangular hole. Rock the knife to connect the cuts.
If you don't have a knife you can just stab a hole with a sharp stick.
If the nut is mature the shell will be strong and will stop your knife. If your knife is strong you can stab through it anyway. If stabbing the side doesn't work you'll need to husk the coconut and poke through one of the "monkey face" holes at the stem end. Some coconuts grow right by the stem in the husk, and you can poke right through the husk at the stem to drink it. Look at the empty nuts laying around to see how the locals drink them.
Step 5: Remove the Plug
Rock the knife to connect the cuts and pry the plug out.
A $1 pocket knife usually isn't strong enough for this sort of thing. A $1 paring knife usually is. Get one with a thick blade. Usually stainless steel knives aren't as good as the kind that can rust.
Step 6: Drink It!
If you have a straw use that.
Otherwise arch your back and drink it like you're in a commercial.
The first time I drank a coconut I didn't like it. I thought it tasted like pine needles and wondered what all the fuss was about. Later my arms went numb from sweating out all my electrolytes. Then I thought coconut juice was the most delicious thing and drank five or six a day. I've heard they have the right combination of electolytes. I also drank a sip of sea water each day. My arms recovered. Some coconuts are so sweet there's no acquired taste or dietary deficiency needed to make them delicious.
Step 7: Carve a Graceful Spout
If you're going to pour out the juice it can dribble and make a mess.
Or maybe come in contact with dirty parts of the skin.
If coconut juice gets on your shirt it will make a brown stain that takes a few hours to show up and is very hard to wash out.
To make things more elegant, try carving a spout as shown. The outer skin cuts easily. It takes just four cuts to make this really sophisticated looking spout.
Step 8: Jelly - Cut the Coconut Open
More steps! There's some delicious jelly lining the inside of the nut. Here's how to get it.
Put the coconut on something solid and hold the knife in a "stab" grip with the sharp edge away from you. Put it in the drinking hole and cut away from you. Push and put your weight into it. You should be able to slash to the stem or beyond. Pull it out and turn the coconut around. Cut the same way as far around as you can.
If you don't have a knife, I've seen people smash coconuts on the ground at this stage to split them open. Jump in the air with the coconut over your head and throw it at the edge of a big sharp rock. Try to hit it on the side. It's more work and kind of messy. It's kind of like an end-zone dance by a gorilla.
You can also husk the coconut on a stake. Expect an instructable on that soon.
Step 9: Split the Nut
Put your thumbs in the drinking hole and pry the coconut apart.
Step 10: Make a Spoon
Cut the skin of the coconut like this and peel it off to make a spoon.
Step 11: Eat the Jelly
Use the sharp edge of the spoon to scrape the jelly from the inside of the nut.
Step 12: Machete Methods
If you have a machete, Star demonstrates how to proceed. If you want to give your mom a heart attack and maybe chop yourself, you can hold it in one hand and chop with the other. Otherwise lay some palm branches on the ground for the coconut to rest on. That way if you miss or chop through you won't wreck the edge. Chop the top of the coconut husk off. Expose the top of the nut inside. Chopping is easier if you cut the husk fibers at an angle. Like sharpening a pencil.
Step 13: Monkey Face
No silly, I don't mean Star, I mean the coconut.
Here's the top of the coconut. Those three spots are the "monkey face". If the coconut were left in the ground long enough it would sprout. A shoot with leaves would grow out of one spot and a root would grow out of another. These are the thin spots in the nut shell. Poke a hole in them and drink with a straw, or pour into a cup. Then chop the nut in half the long way to get the jelly as in step 8.