The disk plate gap was set at 1.02 mm. Water was added during disk milling, which resulted in a solids discharge consistency of approximately 10%. The energy consumption for disk milling was recorded as described elsewhere [18,25]. The size-reduced solids were directly dewatered by pressing using a canvas bag to a solids content of approximately 30%, without a separate washing step. The yield of solid substrate in the form of fibers or fiber bundles was then determined from the weight and moisture content of the collected substrate. The moisture content was determined gravimetrically by drying the collected solids in an oven at 105 °C overnight.