The nibs can now be processed a couple of different ways. One option is to heat them and press them for oil, like olives or sunflower seeds. The oil solidifies at room temperature and that's cocoa butter, which has a lot of desirable properties for cosmetics, or can be added back to the chocolate-making process. Finely grinding the remaining "cake" of pressed out solids yields cocoa powder.
Alternatively, you can simply grind up the nibs whole, and then you have "cocoa liquor," aka unsweetened chocolate.
To make chocolate bars, this is mixed with sugar, optionally milk powder (for milk chocolate), usually vanilla, and usually some lecithin. Lecithin is a fraction purified from different oily foods that acts like a biological detergent and helps emulsify mixtures of fats with things (like sugar) that prefer to dissolve in water. It helps with the texture and stability of the finished product.
Even with finely ground sugar and cacao, this mixture is grittier than "chocolate."
(6/9)
