Three factors – sharpness, size, and alignment – have a big effect on توزيع حجم الطحن. Worn, blunt التروس tend to ‘crush’ the beans with الضغط stress rather than ‘cut’ them with shear stress. As discussed in Lesson 1.02, الضغط forces cause the particles to break up into randomly sized fragments, so blunt التروس produce widely spread particle size distributions, resulting in less even extraction.
Larger التروس seem to generally produce more even grind size distributions,