A process is described for the preparation of water-soluble cellulose hydrolysis products, which comprises admixing cellulose with an ionic liquid capable of solvating or dissolving at least some of the cellulose, said ionic liquid being a compound comprised solely of cations and anions and which exists in a liquid state at a temperature at or below 15O °C, the cations in said ionic liquid having the general formula (I), in which Z represents a nitrogen or phosphorus atom, R1 represents a methyl or ethyl group, each of R2 and R3, which may be the same or different, is selected from C4-3alkyl, optionally-substituted benzyl, optionally-substituted phenyl, and C5-7 cycloalkyl, and R4 represents C1-8 alkyl, optionally-substituted benzyl, optionally-substituted phenyl or C5-7cyclohexyl; in which the optional substituents on a benzyl or phenyl ring are one, two or three substituents selected from C1-4alkyl or alkoxy groups, halogen atoms and nitro groups; and treating the resulting solvate or solution with an acid in the presence of water, said acid having a pKa in water of less than 2 at 25°C.