Mixing and the Waiting Game
Your chocolate liquor is your blank slate -- pure cocoa goodness. Now you get to really decide what kind of chocolate you'd like to make and play with some kitchen science. You can always use the liqueur in lieu of unsweetened chocolate in recipes, but if you want to make chocolate bars, soldier on.
Bittersweet chocolate is usually 15 to 20 percent sugar, while the sweetest milk chocolate can be as much as 75 or 80 percent sugar. A kitchen scale would be helpful in figuring out the proportions that you'd like to use. You can add cocoa butter (up to 20 percent is probably the most you'd want to use) to make a creamier chocolate and a tiny bit of lecithin. For milk chocolate, try an amount of nonfat milk powder equal to or slightly less than the amount of chocolate liqueur. Why not actual milk? Simply put, you don't need the extra liquid or fat. If you'd like to add a flavoring such as vanilla or almond extract, toss it into the cocoa butter (search online for actual recipes if you like).
You can mix all of your ingredients in a bowl before putting them into a melangeur or stone grinder. However, you might also consider putting the whole mixture back into your juicer. Not only will it kick-start the refining process, it will also help get the last of the husks out of the juicer.
Now it's time to refine and conch. Commercial establishments use large-scale machines to separately do these processes, and the conching process involves heating as well. The home machines available today do both at the same time, just due to the heat generated by friction during the process. Refining simply means that you're grinding the sugar and cocoa particles down to a fine, uniform texture. It removes all of the grittiness. Conching is a chemical change that takes place within the chocolate due to the repeated mixing -- it reduces acidity, evenly distributes the cocoa butter within the chocolate and makes it smooth and viscous. Before putting it into your melangeur, melt the chocolate liqueur and cocoa butter (or the whole mixture if you've already mixed it and put it through your juicer) to about 120 degrees Fahrenheit. It will have a gritty, grainy texture.
Turn on the machine and let it go -- this is the longest part of the process. You're looking for no grit left whatsoever and a nice shiny appearance. Most people can't just let their machine run for 10 hours, but you can stop and start it as necessary without any problems. If the mixture solidifies, just re-melt in a very low oven. Some people go as long as three days when refining. Much like roasting, however, you'll want to consider the bean and the ingredients. A dark chocolate made from Forastero can stand up to longer processing, for example.
Finally, chocolate. Right? Not quite yet. If you skip the next step, you might end up with some crumbly, melty, spotty chocolate, all your hard work gone to waste.