The pH of the mixture was adjusted dropwise to about 3-4 with concentrated HCl, so that lignin precipitated in the acidic environment. The pH value was checked with pH test strips (pH 1-14, ChemSolute). In the acidic environment, lignin precipitated. Approximately 20 g of sodium chloride was then added to the mixture of water and precipitated lignin. The aqueous phase was then extracted twice with 50 mL THF and separated from the aqueous phase using a separating funnel. The organic phases were combined and dried over magnesium sulphate. THF was evaporated and the product was then dried at 70°C for 2 h in a vacuum oven at 4 mbar. At the same time intervals, lignin was ground without any additives, mixed with water, acidified, and extracted in the same way to provide a basis for comparison. A schematic representation of the extraction step can be found in the supporting information (Fig. ).