Guidelines

Universal Hygiene has provided the information in this section to help dairy producers evaluate the causes, removal and prevention of milk bacteria, films and odors for excellent milk quality and sanitation.

What is the P.I. Test?
The P.I. Test is the Preliminary Incubation of raw milk samples at 13° C (55° F) before running the standard plate count. P.I. counts are an excellent measure of milk cooling and sanitation practices on the dairy farm. The P.I. Test is used to help detect the presence of physchrotrophic bacteria.

What are Psychrotrophic Bacteria?
Psychrotrophics are "cold loving" bacteria primarily made up of gram negative bacteria such as Pseudomonas, some Coliforms, Flavobacterium for the production of off flavors and odors in milk. The main source of contamination is through poor sanitation on the dairy farm.