Vent system for food processing machine

A machine for processing individual food items comprises a mold plate having multiple longitudinally spaced transverse rows of cavities. The mold plate slides such that the rows of cavities sequentially communicate with a fill slot in a fill plate. Bulk food material fills the cavities and displaces air from them into a breather plate. The breather plate has one or more longitudinal grooves in a working surface. The fill plate has one or more longitudinal grooves in a working surface that communicate with the atmosphere. One or more vent holes in the mold plate communicate with the breather plate and fill plate grooves for all positions of the mold plate at which food material is filling a row of cavities. No air is trapped in the breather plate, and there is no buildup of air pressure that could create a friction force between the mold plate and the fill plate.