Grind the Nibs
Nibs are now ground into chocolate liquor in the juicer. For this step, you add the fine screen to the machine so that any husks that did not get winnowed are separated out and don't get into your finished chocolate. The Champion Juicer has proven to be about the only home unit tough enough to handle this task, although some people have reported that a Cuisinart with a juicer attachment works too.
This step takes time, about 30 minutes for two pounds of nibs. If you rush it, the juicer will heat up too much and impart a bad taste to your beans, or the motor in the juicer will burn out. Aromas here are pungent — still chocolate but with overtones of acetic acid and other volatiles, which will be removed in the next step.