How is Milk Pasteurized

Find out how pasteurizing food increases the shelf life of many products.

Pasteurization is a process of heating food and liquid to a specific temperature in order to slow microbial growth, essentially giving it a longer shelf life. This technique is usually associated with milk where it reduces the number of potentially harmful bacteria such as E coli and salmonella that are present in its raw state.

Bacteria produce enzymes which help them to break down and digest a wide range of organic materials allowing them to divide and conquer.

Heating milk to 71 degrees Celsius (160 degrees Fahrenheit) for 15 seconds changes the shape of the enzymes in the harmful bacteria, rendering them useless and hindering the bacterial growth and multiplication process.

Pasteurization does not stop all the bacteria, which is why you still need to keep it in the fridge. It does, however, significantly lower the concentration of harmful bacteria, leaving your stomach to do the rest of the work.

The process of pasteurizationThe process of pasteurization

1. Fresh milk in – Cold raw milk is drawn into the regenerator section of the pasteurizer for heating.

2. Heating section – Hot water on the opposite side of two metal plates heats the milk to 71″C (160″F) denaturing enzymes responsible for bacterial growth.

3. Cooling section – Warm milk passes through two plates where a coolant on the opposite side of the metal plates chills the milk to below 4″C (39″F).

4. Pasteurized milk out – The pasteurized milk is then sent to a cooled storage tank for packaging and later distribution.

Read The Pasteurization Process