Step 4: Sometimes you will have some chocolate set, so you will have to leave it out of the main mass, as noted in the chocolate image (I will eventually add a problems page to show you why.). Keep working the mush until is becomes thick and matte-like in appearance.
As the chocolate cools it sets into various crystal forms. Cocoa butter can set in multiple forms depending on temperatures and cooling conditions. The three we deal with most are Form II (2), Form IV (4), and Form V (5). Your goal in working the mush is to create a rich supply of Form IV and Form V crystals. The chocolate that has set up is probably rich in Form II crystals.