Science in dairy: pasteurizing milk

Written by: Casey Öztel

Walking past the ice cream and shelves of local stock; Dan and Debbie’s Creamery offers a viewing room. In this room, impressive stainless steel instruments rest. During the work day, a handful of people operate the machines to finish the milk products. Milk has long been a staple in the American diet. Throughout the years, it has been studied and carefully refined due to the large population which consumes milk. Before regulations were passed, milk quality varied greatly.

One of the first diseases known to man, Tuberculosis (TB), is a diagnosis which may be eradicated in the near future. A regulation surrounding milk is partially responsible for this decreasing frequency. Starting in Chicago in the early 1900s, milk was required to be pasteurized. By the roaring 20s, the US Public Health Service began regulating milk pasteurization. During the process, milk is quickly heated to a mild temperature and held for a duration of time. Bacteria, like Mycobacterium tuberculosis responsible for TB, are killed during this process. It is important to note, pasteurization does not reduce the nutritional value of milk.

When milk is pasteurized, it is heated to just below the boiling point. At the boiling point, the milk proteins start to break down. If the milk is allowed to boil, then the nutritional value is likely to decrease. When proteins get too hot they being to break apart, or denature. The instrumentation used to pasteurize milk can have a large influence on the quality produced. That is why when stepping into the viewing room at the creamery, it is impossible to not be impressed. Dan and Debbie obviously take pride in each step of the milk producing process from the milking the cows all the way to it being safely bottled.

  • Posted by Josie Rozum
  • On May 20, 2019