Terminology #

Why be specific #

Kombucha brewing has a great deal of associated mythology. While this provides some interesting reading and makes the brewing process feel magical, it can sometimes make it difficult for new brewers to understand what they are reading online (at least it did for me).

Written communication only really works if we all understand what specific terms mean. This is doubly true for something like a recipe, since the writer is attempting to convey specific instructions. To make things clear at least on this site, I will summarize the terms I intend to use. I don’t make any claim that these are the “correct” terms but they are the ones that make the most sense to me, and I will try to be consistent.

Terms in use #

Starter Liquid or Raw Kombucha #

Unflavored, unpasteurized kombucha that has finished primary fermentation. This should be quite acidic and can be used to start the fermentation process in a new batch. This only refers to liquid.

Biofilm #

The cellulose layer that forms on top of fermenting Kombucha. This is sometimes referred to as a pellicle or SCOBY. But for clarity, I will use the narrowest term possible (biofilm). You can read more about biofilms on wikipedia. This only refers to the solid cellulose layer.

Microbes #

The bacteria and yeast in kombucha that cause fermentation and the creation of its unique flavor. These different microorganisms work together to create kombucha. In general, the yeast eat sugar to create CO2 and alcohol. The bacterial oxidize the alcohol to create different acids, resulting it kombucha’s signature tang. This term refers to both types of microorganisms and is similar to SCOBY, but without all the history that term holds in kombucha culture.

1f #

First stage of fermentation. This is the primary fermentation where the starter liquid transforms sweet tea into raw kombucha. 1f requires oxygen for the bacteria to oxidize the alcohol, so the fermentation vessel is open to the air (with a tight fitting, close knit cover to keep insects and debris out).

1.5f #

An optional stage sometimes used to infuse additional flavors between the primary fermentation and bottling. This is usually carried out similar to 1f, but with some addition made directly to the raw kombucha.

2f #

Second stage of fermentation. This is the fermentation responsible for carbonation in bottles. After 1f, the raw kombucha is bottled with an additional sugar source (usually some type of fruit or berry). This additional sugar is a food source for the yeast. As the yeast consume the sugar, CO2 and alcohol are created. The sealed bottle contains the CO2 leading to carbonation.

Terms I will not use #

Pellicle #

This is a term commonly used to refer to the biofilm. It is somewhat specific, but does have other meanings in more scientific communities. I personally like biofilm because it seems easier to recognize when looking in the jar.

SCOBY #

Symbiotic Culture of Bacteria and Yeast. This term came into use in the late 1990s and is very overloaded in the Kombucha community. Some insist it refers only to the biofilm, others only to the starter liquid, some to both. To avoid this confusion, I will eschew its use entirely in favor of the more specific terms above.