An apparatus and method for macerating raw meat pieces includes two sets of rotating arbors, each having a different primary function. More particularly, the first arbor set is primarily configured to flatten and roughly tenderize the meat. The second arbor set is primarily configured to increase the surface area and tenderness of the meat without breaking the meat apart, though the second arbor set may also further reduce the thickness of the meat pieces. The second arbor set is positioned downstream of the first arbor set by a conveyor such that the meat pieces advancing through the macerator are only macerated by one of the arbor sets at any give time. Each arbor set has a pair of counter rotating shafts.