The Effect of Copper upon the Activity of Bacteria Associated with Swiss Cheese Manufacture

The role of copper in promoting flavor deterioration in butter and fluid milk has been widely recognized. Copper also may interfere with the normal ripening of Cheddar cheese. Thus, Barnicoat (1) observed that maturation of Cheddar cheese made from milk containing from 3 to 6 ppm. of copper was abnormal and color defects developed. Stine et al. Cheese made in stainless steel equipment contained only 0.5 to 1.5 ppm. of copper, whereas that made in tinned copper equipment contained from 0.5 to 33.8 ppm. The degree of contamination was dependent upon the amount of exposed copper on the equipment.