As-built the bolting cabinet is pretty much a requirement for making good flour. Although the stones can be set to make very fine flour, for some reason a few poorly ground berries do get past the stones. I worked very hard to get the stones flat but I think they are still flawed. I'm disappointed that the factory did not provide me with well dressed stones to start out with. I did learn from the quality person at Engstrom that small stones do not make the very best flour, but I think the lack of flatness is contributing to this problem. Anyhow, this means that right now if I want to make 100% extraction flour I have to re-grind the bran to get enough bran into the flour. If I ran the mill without the bolter there would be a tiny amount of unground berries in the flour. I may try to set up the bolter with even courser cloth, so more bran will fall through, but I think the long term fix is larger stones. I am trying to source 600 mm stones now.