Pasteurized Milk Quality

Milk collected from the udders of healthy cows is almost sterile but microbial contaminants are introduced during milking, storage, processing, and distribution. Cleaning and sanitation failures allow contaminating organisms to accumulate in dairy processing equipment, potentially leading to the development of biofilms that can become a significant and persistent source of contamination. On the farm and…

The first article in this series, Raw Milk Micro Testing, focused on Gram-negative bacteria in raw milk with the Preliminary Incubation (PI) Count and Fresh Standard Plate Count (SPC) tests. In this second installment, I would like to discuss another classification of bacteria (Gram-positive HRSF Bacteria) that was not known as a major issue in fluid…

Why do you do it? What do the test results tell you? Is the test you use still a valid one? In part one of this dairy micro testing series, Raw Milk Dairy Micro Testing, I would like to take you on a journey through the development of some of the principal tests used in…

The shelf life of pasteurized fluid milk is challenged by bacterial contamination that enters the finished milk supply through two portals: a) contamination by Gram-negative psychrotrophic bacteria during processing after pasteurization; and b) contamination by Gram-positive spore-forming bacteria that enter primarily through the raw milk supply. In today’s processing environment, where post-pasteurization contamination is largely…