Impedance Measurements to Detect Bacteriophage Problems in Cheddar Cheesemaking.

A simple method is described to detect, within 2 h, complete failure of the starter due to bacteriophages in the manufacture of Cheddar cheese. This method is based on the observation that about 105 disturbing bacteriophages per ml, which cause complete failure of the starter, inhibit the normal impedance decrease brought about by growth of lactic starter bacteria, as recorded in the Bactometer 32 Microbial Monitoring System.