What is Kombucha?

Kombucha is fermented tea! Just like yogurt is fermented milk and sauerkraut is fermented cabbage, Though the Kombucha commercial industry is new, the drink is much older as it has been consumed for hundreds of years in every country on the planet.

Kombucha Ingredients

Tea [Camelia sinensis], Sugar [sucrose], SCOBY [fermentation culture], flavorings [juice, fruit, herbs, etc]

Kombucha Chemical Characteristics

pH = 2.5-3.8

Acetic acid ferment: ~1%

By comparison, vinegar is diluted to 4-8% acetic acid

ABV = 0-2% for traditional, non-alcoholic ferments

ABV = 4-8% for Kombucha beer or high alcohol Kombucha hybrid ferments

Materials Acceptable for Use with Kombucha

Stainless Steel 304 & 316, 1

Neoprene Vinyl

1 British Stainless Steel Association – 304 types are used for most applications, including handling and storage.

Draft Kombucha Components

In a draft Kombucha set up, here are the components that come into contact with product.

Keg Coupler – Probe – 304 Stainless Steel
Product Washer, between the metal contacts of Tailpiece and Coupler – Neoprene
Product line Tailpiece for Coupler connection – 304 Stainless Steel
Product line – Vinyl
Tower Shank – 304 Stainless Steel
Faucet – 304 Stainless Steel

Antimicrobial Properties of Kombucha

Kombucha is naturally antimicrobial. It’s low pH and mix of organic acids have been shown to kill known pathogens on contact.

The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha. 2, 3, 4

Pathogens Sensitive to Kombucha

Staphylococcus aureus
Shigella sonnei
Escherichia coli
Aeromonashydrophila
Yersinia enterolitica
Pseudomonas aeruginosa
Enterobactercloacae
Staphylococcus epidermis
Campylobacter jejuni
Salmonella enteritidis
Salmonella typhimurium
Bacillus cereus
Listeria monocytogenes
Helicobacter pylori

For more information, check out our Best Practices Page

2 Sreeramulu, Guttapadu, Yang Zhu, and Wieger Knol. “Kombucha fermentation and its antimicrobial activity.” Journal of agricultural and food chemistry 48.6 (2000): 2589-2594.

3 Sreeramulu, G., Y. Zhu, and W. Knol. “Characterization of antimicrobial activity in Kombucha fermentation.” Acta Biotechnologica 21.1 (2001): 49-56.

4 Cetojevic-Simin, D. D., et al. “Antiproliferative and antimicrobial activity of traditional Kombucha and Satureja montana L. Kombucha.” J BUON 13.3 (2008): 395-401.