Abstract: A closed food processing vat particularly for use as a cheese curd vat where at least one rotatable vertical shaft within the vat has a pivotally associated cutter frame stopped so the frame when the shaft is rotated in one direction is moved to a cutting position extending as a radius from the shaft with the cutting edge of the blades in the frame leading to a stirring position when the shaft is rotated in the opposite direction with the frame automatically moved as a reaction against the product in the vat to a position at an angle to the radius so that the projection of blades in the frame relative to the direction of rotation is increased to stir the product.The present invention relates to food processing apparatus which has been particularly although not solely designed for use in cheese making.