The present invention relates to a process for solubilizing keratins from a keratin containing starting material such as poultry feathers. The keratins are may be solubilized using a sulphide under alkaline conditions. In the process the cysteine residues of solubilized keratins and are partially modified, e.g. by alkylation. The conditions of solubilisation and partial modification are chosen such that the keratins are also partially hydrolyzed. The partially modified and partially hydrolyzed keratin may be used as stable dispersions e.g. for the production of films and coatings by casting.