What is HTST Pasteurization?
HTST, or high temperature short time pasteurization, has become one of the most common methods of pasteurization today. It is more frequently known as flash pasteurization, or the “continuous method”. Pasteurization destroys pathogenic organisms such as bacteria, viruses, protozoa, molds and yeasts in milk products to reduce bacterial content and deliver a safe product to the public. HTST pasteurization uses stainless steel heat exchange plates where product flows on one side while the heating media flows on the opposite side to raise milk temperatures to at least 161° F (72° C) for at least 15 seconds*, followed by rapid cooling. If the fat content of the milk product is 10% or greater, or a total solids of 18% or greater, or if it contains added sweeteners, the specified temperature shall be increased by 5°F (3°C).
Why is HTST Pasteurization the Preferred Method?
High temperature short time pasteurization is a continuous process that efficiently and effectively destroys microorganisms in milk products. An HTST pasteurization system is a modular unit that includes a plate-and-frame heat exchanger, stainless steel balance tank, pumps, holding tube, valves piping and controls. Vat pasteurization, or the holding method, is the oldest method for pasteurizing food products. However, over the years HTST has gained favor in the food industry for multiple reasons:
- Large equipment capacity allows large volumes at one time
- Continuous process allows for bottling to begin when pasteurization begins
- Highly energy efficient
- Minimal chance of damage to milk product
- Fully utilized regeneration
- Equipment is easy to clean and sterilize
- Thermophiles are less troublesome
Do I need an HTST Pasteurization System?
The volume of milk product that is going through the pasteurization process each day will determine if HTST pasteurization is the right method for you. If a processing plant handles volumes in excess, the continuous method would be the most economical and successful option. Since HTST pasteurization requires more components, it can be more expensive than the holding method.
*Standards from the Grade “A” Pasteurized Milk Ordinance 2013, provided by the U.S. Department of Health and Human Services, Public Health Service and Food and Drug Administration.