The present disclosure relates to a process for preparing polyurethane moldings, including the steps of providing a reaction mixture (M), including at least one polyisocyanate, and at least one component with two functional groups which are reactive towards isocyanates, introducing the reaction mixture (M) into a mold and allowing the reaction mixture (M) to react to form a polyurethane molding. In the first step, at least one additive selected from vegetable oils is added to the mixture (M). The present disclosure also relates to a polyurethane molding obtained or obtainable according to said process and the use of a polyurethane molding according to the invention as sole of a boot or part of a sole of a boot.