HTST Pasteurizing Time & Temperature
Ultra-Pasteurized Time & Temperature
The process of pasteurization is named after Louis Pasteur who discovered that spoilage organisms could be inactivated in wine by applying heat at temperatures below its boiling point. The process was later applied to milk and remains the most important operation in the processing of milk.
How Is Our Organic Milk Pasteurized?
We treat our milk very gently so the naturally fresh taste can come through in every sip. Because of our unique location on the coast of Northern California, we want to retain the special taste that comes from the sweet grasses covering our hillsides.
Our organic milk is pasteurized using the HTST (high temperature-short time) method. The raw milk is heated at 170 degrees Fahrenheit and immediately cooled to 40 degrees or below. This slow-heat method gives our milk 16 days of shelf life. The benefit of pasteurization, destroying all bacteria that are harmful to health, is assured while still keeping our product as fresh-tasting as possible. You will notice a fresher, less-cooked flavor with milk that is pasteurized at a lower temperature.
You'll notice that many types of organic milk are labeled 'Ultra-Pasteurized'. When used to describe a dairy product, this means that the milk was heated to or above 280°F for at least two (2) seconds. Ultra-pasteurized products can have shelf life of up to 60 days.
We don't like ultra-pasteurized milk because we think it destroys the taste of the milk. Furthermore, we think it's unnecessary. The brilliance of Pasteur was his discovery that you did not have to boil something to remove pathogens. We always adhere to the highest standards of safety and we respect the nature of our milk. Once you try our milk you'll taste the difference.
USDA Definition of Milk Pasteurization:
"The heating of every particle of milk or milk product to a specific temperature for a specified period of time without allowing recontamination of that milk or milk product during the heat treatment process."
There are two distinct purposes for the process of milk pasteurization:
Public Health - to make milk and milk products safe for human consumption by destroying all bacteria that may be harmful to health (pathogens).
Extends Shelf Life - to improve the keeping quality of milk and milk products, HTST pasteurization can destroy some undesirable enzymes and many spoilage bacteria. Shelf life can be 7, 10, 14 or up to 16 days depending on the time and temperatures during processing. Minimum temperature and time requirements for milk pasteurization are based on thermal death time studies for the most heat resistant pathogen found in milk, Coxelliae burnettii.
Ultra-Pasteurized describes a dairy product that has been heated to or above 280°F for at least two seconds. Ultra-pasteurized products can have shelf life of up to 60 days.
To ensure destruction of all pathogenic microorganisms, time and temperature combinations of the pasteurization process are defined below:
High Temperature/Short Time (HTST):
| Temperature | Time |
| 145°F | 30 minutes |
| 161°F | 15 seconds |
| 191°F | 1.0 second |
| 194°F | 0.5 seconds |
| 201°F | 0.1 seconds |
| 204°F | 0.05 seconds |
| 212°F | 0.01 seconds |
Ultra-Pasteurization:
| Temperature | Time |
| 280°F | 2 seconds |