Directly after the grinding process the temperature inside the grinding bowl is measured to confirm that the temperature is below 90 °C and no following reactions e.g. dehydration of sugars to furfural and hydroxymethylfurfural occurs. Following mechanocatalytic partial depolymerization, a product amount corresponding to 400 mg without acid loading is extracted in 40 mL deionized water for 1 h at room temperature. The solid residue is filtered off, dried overnight under vacuum at 40°C and then weighed to determine the insoluble fraction gravimetrically. The filtrate is analyzed by HPLC and furthermore GPC measurements are carried out to determine the molecular weight distribution.