No, no, no way. Pasteurisation is heating a food product up to a point all microorganisms are destroyed (usually to just below 100 degrees C). This is the nuclear option when it comes to food. Pasteurisation kills all the nice probiotics that you normally get from pure kombucha. Next to kicking puppies, pasteurisation is the most “anti-kombucha” thing you can do.
Why Do Some Companies Pasteurise?
Then why do companies, usually larger ones, do this? They pasteurise in order to lock in a preferred flavour profile and to prolong shelf life. Real kombucha is a living culture and remains active converting sugars into carbon dioxide, some alcohol and good microbes. This results in the flavour changing slowly, usually becoming more tart over long periods of time. As for shelf stability: if something is dead inside and sealed, well, it “lasts” forever… Be sure to check when you buy kombucha in a store - if it is pasteurised, put that sh*t back.
Real Kombucha is Naturally Safe
What about bacteria and other dangerous microbes in unpasteurised kombucha? Kombucha is very acidic with a pH of below 3.0. Unlike milk (pH 6.7), kombucha is an environment in which pathogens find it very difficult to grow. For example, the most lethal pathogen of all is botulism and that cannot grow in a pH below 4.6, and we are well below that. Properly brewed kombucha does not ever need to be pasteurised to destroy harmful pathogens. They just aren’t there.