We recently published a blog post discussing fermentation and near beer. That post briefly explained how brewers follow standard fermentation processes to create beer before removing the alcohol content. This post will continue the same line of thinking by discussing how kombucha is brewed.

 

Kombucha is a fermented tea drink that combines some type of tea with the Manchurian mushroom known as the kombucha. Fermenting the tea gives it a sweet and tart taste that is often enhanced with other ingredients. Right now, kombucha is one of the hottest beverages on the market. People seem to love it.

 

Starting with the Tea

 

Manufacturers have their own ways of doing things but, by and large, the standard rule of thumb is to start by brewing tea as normal. A manufacturer might brew large vats of black or green tea just as if they were going to make a bottled iced tea product. Once the tea is brewed, it’s off to fermenting.

 

Fermentation alters the taste of the tea considerably. So brewers might choose specific types of teas with an eye on achieving a certain flavor in the end product. There is no particular type of tea that makes a superior kombucha.

 

Fermentation in Stainless Steel Tanks

 

Brewed tea is loaded into stainless steel tanks for fermentation. Again, brewers all have their preferred ways of doing things. We know one particular company that uses separate fermentation and brite tanks, specifically because they use the brite tank to more tightly control carbonation. But in theory, a single unitank would work equally well.

 

At any rate, a combination of bacteria and yeast – known as SCOBY – is added to the brewed tea to start the fermentation process. Natural sugars in the tea feed the bacteria, which ultimately leads to fermentation. Bacteria transforms the sugar into other components.

 

Kombucha manufacturers do not want their beverages containing alcohol. Unfortunately, alcohol is one of the byproducts of fermentation. So as we discussed in the recent post mentioned above, there are ways of dealing with this particular issue.

 

Temperature-Controlled Fermenting

 

One method of dealing with alcohol production is to force fermentation to occur in an environment where temperature and pressure are tightly controlled. By keeping the temperature cool enough, brewers can reduce the rate at which alcohol is produced.

 

A similar process, known as arrested fermentation, only allows fermentation to progress to a certain point. Not letting it go any further limits the amount of alcohol the yeast ultimately produces.

 

Post-Fermentation Heat Distillation

 

There are kombucha makers who aren’t thrilled by temperature-controlled or arrested fermentation for the simple fact that they feel like both processes limit their ability to create unique flavor profiles. So instead, they rely on heat distillation after fermentation.

 

Heat distillation applies heat to the fermented batch at a temperature high enough to evaporate alcohol content without severely degrading flavor. But just as with the other two processes, flavor degradation is a matter of preference. There are manufacturers who prefer arrested fermentation because they think heat distillation ruins the flavor.

 

It’s Off to Bottling

 

The final step in all of this is bottling. The general rule of thumb is to condition bottles first, then fill them with the carbonated kombucha before capping. It is expected that some minor fermentation will continue in the bottle. When the consumer opens a bottle, they should be greeted by an effervescent odor and a fair amount of fizz.

 

So now you know – fermentation isn’t just for alcoholic beverages. Kombucha manufacturing relies on tightly controlled fermentation as well. It is the fermentation process that makes kombucha what it is.