Pasteurization is a process named after the scientist Louis Pasteur. It kills pathogens in food by heating. For the dairy industry, the terms "pasteurization", "pasteurization" and similar terms refer to the process of heating each particle of milk or milk products to one of the temperatures given in the following table in properly designed and operated equipment and continuing at or above that temperature for at least the corresponding specified time:

Temperature time pasteurization type
63 º C (145 º F) * 30min vacuum pasteurization
72 º C (161 º F) * 15s high temperature short time pasteurization (HTST)
89 º C (191 º F) 1.0 s HHST
90 º C (194 º F) 0.5 second HHST
94 º C (201 º F) 0.1 s HHST
96 º C (204 º F) 0.05 seconds HHST
100 º C (212 º F) 0.01 seconds HHST

138 º C (280 º F) 2.0 seconds ultra pasteurization (UP)

If the fat content of dairy products is 10% or more, or contains added sweeteners, or is concentrated (concentrated), the specified temperature should be increased by 3 º C (5 º F). Egg liquor shall be heated to the following temperature and time specifications at least:

Temperature time pasteurization type

69 º C (155 º F) 30 min vacuum pasteurization
80 º C (175 º F) 25 seconds high temperature short time pasteurization (HTST)
83 º C (180 º F) 15 seconds high temperature short time pasteurization (HTST)
The original pasteurization was barrel pasteurization, where milk or other liquid ingredients were heated in a large pot for at least 30 minutes. It is now mainly used in the dairy industry to prepare starter cultures in cheese, yogurt and buttermilk, and to pasteurize some ice cream mixtures.

Today, the most common pasteurization method in the United States is high-temperature short-time (HTST) pasteurization, which uses metal plates and hot water to raise the temperature of milk to at least 161 ° F for at least 15 seconds, and then quickly cools. High temperature short time (HHST) is a process similar to HTST pasteurization, but it uses slightly different equipment, with higher temperature and shorter time. For products considered to be ultra pasteurized (UP), they must be heated to no less than 280 ° for two seconds. The UP pasteurization can make the product have a longer shelf life, but it still needs to be refrigerated.

Another method, aseptic processing, also known as ultra-high temperature (UHT), involves heating milk using commercial aseptic equipment and packing it in a sealed package under aseptic conditions. This product is called "shelf stable" and does not need to be refrigerated before opening. All aseptic operations shall be filed with the "Process Administration" of the Food and Drug Administration. No time or temperature is set for aseptic treatment; The competent process department shall determine and verify the appropriate time and temperature according to the equipment used and the products processed.