My dentist was telling me how screwed up people's teeth were from eating stone ground flour back in the day due to the stone particles wearing down their teeth, and it got me thinking of whether or not there was a way to grind grains without getting teeth destroying particles in it. I'd be interested in hearing all the methods/materials, and the older the better :)
One of the notable points in archaeology is how flat teeth get worn from high consumption of flour. In the Neolithic it allowed pressure-flaking techniques using the teeth, that would not work if they weren't dead flat.
I can't think of a single method before the industrial steel tools that didn't involve stones, whether a water-driven grist mill or manos & metate, except Japanese methods of pounding mochi rice into flour. This uses a stump hollowed into a cylinder and a suspended piece of log that fits it closely. It might be used elsewhere in Asia.
Question, could the stones not be filtered/meshed out or spat out like grape seeds when consuming products made from said flour?