What you're about to read has been highly guarded by the super mega corporate chocolate producers of the world. The short of it is that despite the ultra-complex images of chocolate factories you may have seen (Willy Wonka's included), high quality dark chocolate is very easy to make all by yourself in your own kitchen in a matter of hours. In the interest of not listing multi-hundred dollar pieces of equipment, the chocolate you will end up with will have a rustic texture, and will be excellent for eating and cooking.
A normal household oven
A baking sheet that will fit in the oven
A kitchen scale
A hair drier
A Champion brand juicer (or similar auger style--I have a Solo Star II)
A rubber spatula
Aluminum foil or parchment paper
A coffee grinder (cheap whirly blade type, not the fancy burr type)
A friend (choose wisely since you will have to share your chocolate with this person :)
16 oz unroasted whole cocoa beans (if you can only find roasted, just skip the roasting step). You can find these at health food stores like Whole Foods.
***If you only have nibs available, get roasted ones and skip to Step 3.***
Granulated white sugar (DO NOT use powdered sugar --it contains corn starch, and you don't want that in your chocolate)
Step 1: Roasting
Roasting the cocoa beans is essential to develop the "chocolate" flavor. Its also pretty easy to do (there is a lot of science to roasting cocoa, but we won't get into that here)
1. Adjust an oven rack to the middle position and pre-heat your oven to 300F.
2. Spread your unroasted beans out on your baking sheet so they are in a single layer.
3. Once the oven is preheated, place the pan in and start your timer. Roast the beans for 30 minutes. For your first time trying this, pay close attention to the smell. When your beans first start heating, you might notice an acidic smell coming off--this is normal. What we want to do is cook that off and wait until they start smelling like brownies. Because there are endless variations on how to roast and beans vary in how much they should be roasted, I've suggested a very "average" roast. You can experiment with future batches.
4. At 30 mins, pull the beans out and place the pan in front of a fan to cool. If you don't have a fan, don't worry, just let them cool until they are cool enough to handle.
Step 2: De-shelling
Now comes the fun part--removing all the shells from the roasted cocoa beans! Remember that friend I mentioned? Now is their time to shine. Each bean needs to have its shell removed. After roasting, the shells will be brittle and should crack off easily (some will be harder than others). The nibs inside will also break apart, this is ok. This is tedious and can get tiring and will ruin a manicure, but the alternative is to spend lots of money and buy an industrial machine to do it for you. On second thought, you might want to get two friends to help...
As you de-shell, keep the beans/nibs in one bowl, and the shells in another (the shell can be thrown away or composted, but keep in mind cocoa shells are still just as bad for dogs as chocolate is, so don't let Fido find them!). And don't worry if there are a few bits of shell in with the cocoa nibs, they will get filtered out by the juicer.
Step 3: "Refining"
Now is the messy part, and that friend will come in handy here, too.
The de-shelled cocoa beans need to be run through the juicer. If you aren't sure if your juicer can handle this, check the brochure--any juicer that can make nut butters should be suitable. What you want is for the juicer to grind AND heat the cocoa so that the cocoa butter present in the beans melts** .
With the filter screen in the juicer, and a bowl under the "juice" port and one under the "pulp" port on the juicer, slowly start adding the nibs. Don't rush, you can overload the juicer. At first almost all of what you add will come out the "pulp" port. Once you have run it all through, do it again. Each subsequent pass will heat the mass and more and more will melt through the filter screen and come out the juice port, while less comes out the pulp end. Each time, run what comes out the pulp end through, you will be collecting what is called cocoa liquor--partially refined, liquified cocoa mass--flowing out the juice port. At a certain point the only thing coming out the pulp end should be cocoa shell, since you have de-shelled by hand, almost nothing should come out. You are done when nothing or very little comes out the pulp end. You should have a nice bowl of melted cocoa liquor.
**If your juicer doesn't generate enough heat (i.e., nothing comes through the juice port), have that friend point a hair drier at the auger end of the juicer until everything starts melting and flowing smoothly. Be careful not to blow all your cocoa away with the hair drier as it comes out of the juicer (I've learned this from experience).
Step 4: Pre-grinding and Formulating
You will need to weigh your cocoa liquor in order to formulate your final chocolate's percentage. I like a dark chocolate so I never go lower than 70%.
Here's how it works:
if you want your final chocolate to be a 70% dark chocolate, take the weight of the cocoa liquor (in grams), and divide that number by 70. Take the resulting number and multiply that by 30--that is the grams of sugar you will need to add to make the final batch a 70% dark chocolate. See, math is fun when it makes chocolate!
Now, weigh out the amount of sugar you calculated for your custom chocolate. Pre-grind the sugar in small batches in your coffee grinder. You only need to grind for about 30 seconds to get a nice powdered sugar. With a rubber spatula, mix the freshly powdered sugar into the cocoa liquor, making sure there are no clumps. While mixing, have a friend lay out a piece of parchment or foil on a baking sheet (aren't friend's great?)
Ok, i'm sure the suspense is killing you---once the sugar is mixed in, have a taste! (I'll pretend like I didn't see you tasting the cocoa liquor :) Once you have a few batches under your belt, you can add spices and other dehydrated goodies at this step, so long as they don't contain water or moisture. Water will ruin chocolate (even just a drop or two).
Step 5: Dispensing and Setting Up
You are almost done---All that's left to do is to dispense your chocolate into portions onto the lined cookie sheet.** If you have chocolate molds, use them. With a spoon, portion out the liquid chocolate onto the cookie sheet. When done, pop it in the fridge for 15 minutes. Once they are solid, they are ready to eat. They will melt in your hands because they are untempered, but if you keep them in a tupperware in the fridge or freezer, it will slow their melting (and slow the formation of fat and sugar "bloom"---the swirls and speckles in the picture).
Pat yourself on the back, because you just made handmade chocolate from scratch! Now go out and brag to your friends about your accomplishment, but be prepared to share!
**I'm deliberately skipping tempering the final chocolate because that is a whole science by itself, but there are plenty of websites that explain how to do it.