His parents in Bolivia sent him a giant lump of pure cocoa mass which he grated.
The beans are ground into cocoa mass (cocoa paste).
The cocoa mass is then milled and kneaded smooth for hours or even days, in a process called conching.
The higher the percentage of cocoa mass, the more strong, bittersweet, complex flavors in the chocolate.
Dark chocolate (about 50 percent to 99 percent cocoa mass) is generally cocoa mass, sugar and lecithin.
For milk chocolate (5 percent to about 50 percent cocoa mass) manufacturers add dry or condensed whole milk.
Vegans have a non-dairy equivalent made of sugar (non-refined), cocoa mass, cocoa butter, and vanillin.
If it's dark, is it bitter, bittersweet or sweet (depends on the % cocoa mass)?
The nibs are then ground to cocoa mass, pure chocolate in rough form.
Because this cocoa mass usually is liquefied then molded with or without other ingredients, it is called chocolate liquor.