Low-Temp Pasteurization


The practice of using heat to extend the life of food dates to the Middle Ages, when wine and beer were heated to prevent them from souring.  Thus, when Louis Pasteur developed the process of pasteurization in 1864, his goal was to lengthen the life of his favorite wine.  Once it was discovered that pasteurizing milk not only lengthened its shelf life, but also destroyed deadly microorganisms that spread diseases, pasteurizing milk became a widespread practice in Europe, and slowly caught on in the U.S.

Reformers pushed for pasteurization in the U.S. in response to a growing public health crisis in the early 20th century: the spread of infectious diseases through unsafe “slop milk” produced in urban dairies that were located next to whiskey distilleries.  In 1908, Chicago was the first city to IMG_4429require that all milk sold within its limits be pasteurized, and in 1924, the U.S. Public Health Service developed the Standard Milk Ordinance to assist states with voluntary pasteurization programs.  By the late 1940s, all milk sold in the U.S. was required by law to be pasteurized.  Historians agree that pasteurizing milk led to a significant decline in the spread of infectious diseases and the infant mortality rate in urban areas.


Different  methods of pasteurization affect the taste and quality of milk in different ways.  At Farmers Creamery, we use Batch or VAT Pasteurization. All milk was initially pasteurized in this manner.  A batch pasteurizer consists of a temperature-controlled, closed vat.  The milk is pumped into the vat, heated slowly to a minimum temperature of 145° Fahrenheit, held at that temperature for a minimum of 30 minutes, cooled, and then pumped out of the vat.  This method is relatively rare today, and is used mainly by local and regional creameries.  The milk in Kalona SuperNatural™ fluid milk, and butter has been batch pasteurized.

Milk that has been pasteurized at low temperatures differs significantly from milk that has been pasteurized through higher temperature methods, which include Higher Heat Shorter Time (HHST), Ultra Pasteurized (UP), and Ultra High Temperature (UHT).  UP milk, for example, is heated to a minimum of 280° F for a minimum of two seconds, while UHT milk is heated to temperatures between 275° and 300° F, using commercially sterile equipment to produce a shelf stable product that does not require refrigeration until it has been opened.


We believe that low temperature pasteurization is preferable.

First, low temperature pasteurization destroys dangerous pathogens, but not the helpful bacteria that our bodies need.  Lower temperatures also preserve the fabulous, fresh flavor of milk.