A system for processing agricultural items includes a first member having a first surface, a first axis, and a partially cylindrical space, the first surface being an inner surface of the partially cylindrical space. The system also includes a substantially arcuate second member having a second surface and a second axis, the second member being disposed at least partially in the partially cylindrical space, and the contoured second surface being an outer surface of the second member. The first surface and the second surface are substantially opposed to each other. One of the first and second surfaces substantially tapers toward another of the first and second surfaces along the first or second axes. The first and second axes are respective first and second circumferential axes.
