Abstract: For the recovery of the protein from oil seeds, particularly from soy beans, grinding is effected under omission of a suspension liquid, i.e. substantially in dry condition of the oil seed, by applying pressure and friction until the cell walls of the oil seed are opened. This is preferably realized on a friction roller refiner comprising at least two rollers of different speed, i.e. for example on a three-roller-refiner, a five-roller-refiner or also at least two two-roller-refiners. Surprisingly, in this way the expenditure in energy is reduced and the quality of the product is improved.