The invention relates to a method and to a system for processing plant remains in particular shells of seeds and nuts even more in particular shells of cocoa beans shells of grain seeds and rice remains. The method comprises the following steps: (i) providing plant remains having a shell portion of at least 20 wt%； and (ii) at least partially hydrolyzing constituents of the plant remains in particular at least partially hydrolyzing and/or fermenting a carbohydrate a fat and/or a protein. A liquid phase having dissolved constituents and a solid phase can subsequently be separated. The solid portion can be used as dietary fiber and the liquid phase can be used as feed for a biogas plant.
