Lesson 4 - Milling Principles
This lesson explains the objectives of milling and how mills are designed to achieve them. It details how malt is conditioned for dry milling and how we analyse grist particle size profiles. Finally, it explains how milling affects downstream brewing processes.
Point of reflection – reconvene
Welcome back. So, what were your thoughts?
The greater the degree of modification, the more friable the grain is. Therefore, for the same mill, a well-modified malt will form a grist with a higher proportion of the smaller particle sizes. An under modified malt’s grist will have a greater proportion of larger sized particles like husk and coarse grits. There is, however, a ‘but’! If the analysis was on a grist produced by a hammer mill, the degree of modification would have less effect as everything leaving a hammer mill must pass the screen, so all particles will be smaller than the screen. That said, we may find more grist in the lower (finer) trays, as the malt will be easier to obliterate on impact.