The Different Teas for Your Kombucha Brew

I have finally been able to start reading the book Kombucha - Healthy beverage and natural remedy from the Far East by Gunther W. Frank. Wondering which tea(s) to use to brew your kombucha? Here's the quick and dirty about the main varieties of tea and how they relate to your brew.

Black Tea

• Examples: Russian and Ceylon tea
• Fermented
• High caffeine content
• Produces the more typical apple cider vinegar taste of kt
• Using more of it increases the ratio of yeast to bacteria in your brew (3)
• What Kombucha tea is "typically" brewed with

Oolong Tea

• Semi-fermented (1, p. 20)
• Inbetween green and black tea in taste and appearance (1, p. 20)

Green Tea

• Examples: Gunpowder, Jasmine, and white tea
• Comes from the same plant as black tea, but is unfermented (1, p. 19)
• Can contribute an astringent quality to kt
  
• Lower caffeine content than black tea
• Using more of it decreases the ratio of yeast to bacteria in your brew (3)
• Often used because of its numerous health benefits

Yerba Mate (2)

Yerba Mate

Herbal Teas

• Avoid teas with too many volatile oils (ex. sage, peppermint, chamomile, and St.-John's-Wort), which can alter the microorganism balance in the Kombucha culture over time (1, p. 25)
• Used for their medicinal properties and for individuals who want to avoid caffeine (1, p. 25)
• The Kombucha culture feeds on the nitrogen in herbal teas (2)

Herbal Tea Possibilities with Kombucha Tea:

• Rooibos (2)
• Recommended by Pastor Hermann-Josef Wendinger: Equal parts bilberry leaves, raspberry leaves, blackberry leaves, and blackcurrent leaves (1, p. 25)

Recommendations Regarding Herbal Teas

• Include at least some green or black tea in your herbal brews to "[make] the best nutrient solution for the Kombucha culture" (1, p. 25)
• According to Happy Herbalist, brew with 25% "real" tea and 75% herbal tea. OR, ferment 3 brews with herbal teas and every fourth batch use "real" tea (2)
• Add herbal teas in the bottling process

Advantages of Black Tea vs. Herbals

• Produces the highest concentrations of lactic and gluconic acid (1, p. 28)
• Provides the "best conditions" "as a source of mineral nutriments for the culture" (1, p. 28)
• Bing (1928) "describes the Kombucha culture as a community of living things which are particularly adapted to a nutrient milieu rich in purine, and which need this rich supply of purine to maintain their metabolism." (1, p. 28). Black tea contains this necessary purine (1, p. 29).
• According to Bing, the tannin content of the tea also affects the formation of the zoogloea (the new baby mushroom that form at the surface) (1, p. 28)
• Herbal teas contain higher amounts of volatile oils and phenol than black tea. And because the volatile oils float to the surface where the new baby mushrooms grow, they can destroy/inhibit bacteria in the Kombucha culture and change the culture's composition (1, p. 29)
• Herbal teas contain more germinal spores than black teas, which can "germinate in the warm nutrient solution" (1, p. 30)

Which teas do I brew with?

• I typically enjoy using a combination of green and black teas in ratios of around 3:1 or 3:2. I also do brews using only black tea, such as only Ceylon, Darjeeling, or Assam tea.

Read more about different tea types for your kombucha brew at Happy Herbalist and Seeds of Health UK.

Sources:
1. Frank, Gunther W. Kombucha - Healthy beverage and natural remedy from the Far East. 4th ed. Austria: Wilhelm Ennsthaler, 1994.
2. http://www.happyherbalist.com/differentteas.aspx
3. http://geocities.com/kombucha_balance/

Kombucha Brewing Workshop

I am happy to announce that my next Kombucha Brewing Workshop will be in collaboration with Slow Food BU, a club that I am involved with.
Date: Tuesday, October 27
Time: 7:45 pm - 9 pmLocation: Sargent College (635 Commonwealth Ave., Boston, MA 02215), Room 220Cost: Free
Open to the public
ATTN: Due to demand, this workshop will also be a potluck so we can enjoy some good food while drinking kombucha tea! Bring a dish to share if you can, and we will supply the beverages. :) You are still encouraged to come even if you cannot bring any food. But do remember to bring your own plates and utensils if you would like to eat, so we can reduce our waste!
Traced back to Chinese origins to around 220 B.C., numerous health promoting and detoxifying effects have been attributed to Kombucha Tea, also referred to as the "elixir of life."

While Kombucha can cost $3+ a bottle, it is very inexpensive to brew your own! The workshop will include a demonstration on how to brew kombucha tea, and topics covered will include:

• Required materials
• The traditional brewing method
• Bottling
• Where to obtain SCOBYs
• Growing your own kombucha mushroom
• The continuous brewing method

Several flavors of home-brewed kombucha tea will be available for sampling, and a few SCOBYs may also be up for adoption at this skillshare!

*PLEASE NOTE* Although it's not required, if you think you would like a kombucha mushroom from this workshop, bringing an old glass jar (such as an applesauce jar, around 24-32 oz., or any jar of similar size) to exchange for the mushroom would be greatly appreciated.
Already brew your own kombucha tea? Please consider coming and bringing some of your own kombucha so we can have a taste test, or bringing any extra SCOBYs you have to spare!

Please join us and hope to see you there!

Any questions or comments? Contact me!

The Kombucha Journal + Kombucha Mailing List + Book + Funny Video!

I recently came across the website The Kombucha Journal by Kombucha Guru, Günther W. Frank. Not only is The Kombucha Journal available in 30 languages, but it also hosts a Worldwide Kombucha Exchange where you can find kombucha starters and also offer to share your mushrooms with others.

On the site I found a Kombucha Mailing List, which so far has been wonderful. However, the mailing list is quite active- so don't say you weren't warned!

I was so excited with all of these new discoveries, that I broke down and bought Frank's book "Kombucha, Healthy beverage and natural remedy from the Far East." I cannot wait to receive the book, and I will write posts about it when I do!

And through the kombucha mailing list, I also found out about the video, Kombucha and You. The video is extremely entertaining, and I would highly recommend it for a good laugh! Although, it illustrates more of what you shouldn't do with your kombucha mushroom than what you should. :)

Factors Affecting Your Brew

photo source: http://www.happyherbalist.com/timeandtemp.aspx

I just love this chart from Happy Herbalist, which shows how various elements in kombucha tea are affected with time. As fermentation time increases,

• The acidity of kombucha tea increases
• The pH, sugar content, and alcohol content of kt decrease

With more fermentation time, the yeasts will have more time to convert the sugars → alcohol + CO2 (a waste product that is released into the air), decreasing the sugar content.
Meanwhile, the bacteria will have more time to convert the alcohols → beneficial acids, increasing the acidity, and lowering the pH and alcohol content of the kombucha.
Furthermore, the warmer the environment, the faster the kombucha will brew- which is something to keep in mind in the colder, winter months and the hotter, summer days. Finally, another factor that speeds up the fermentation process is adding more starter tea when brewing.

Kombucha Around the World

So apparently I have a new found love for maps, and could not help but create another Google Map with the locations of your oh-so-dear kombucha companies! The link to the map is here.

Whether you purchase kombucha tea or brew your own, it's fun to see where the brands are coming from. And for you locavores out there, the kt's origins may also be another factor to consider!

*Note* - I am looking for more kombucha companies to add to the map! If you know of a company that I have not included, whether it's in the U.S. or elsewhere, please feel free to leave a comment, send me an e-mail, or get in touch with me in some way, and I will update the map accordingly!

Thanks, and enjoy!

Where to Buy Kombucha Around Boston, MA - Part II

I am very excited about this new Google Map that I created with locations that sell kombucha tea around Boston!!! With Google Maps, it will be much easier for me to update new locations that sell kt as I find them. For a link to the map, click here. And if you know of any other locations that I have left out, or if you have any suggestions for my map, please let me know! I'm sure others would appreciate it. :)



On another note, I have now relocated my kombucha brews to my kitchen cabinet.

For whatever reason, it has already been getting colder lately around Boston. (*sigh.* I wish it were still the middle of summer!) Since I tend to open my windows every now and then for the fresh air, my room can get chilly at times, too- which also makes for a slower kombucha ferment.

Because my kitchen tends to be warm, it is a good location temperature-wise for my kombucha brew. However, keeping your ferment in a cabinet in the kitchen is highly recommended- SCOBYs are not fond of smoke! And you might not want to keep your brew in too tight or small of a cabinet, either- kombucha mushrooms also like their oxygen!

Overall, keeping your ferment in a closet or cabinet can be very helpful if you would like to set it aside in an undisturbed spot. Just remember not to forget about your brew!

Cornell Study - Part II

Welcome to Part II of The Cornell Study! As mentioned in my last post, I will be discussing the finds C.J. Greenwalt, R.A. Ledford, and K.H. Steinkraus made from performing their research in their study "Determination and characterization of the anti-microbial activity of the fermented tea Kombucha."

Again, their MISSION for the study was "to determine and characterize Kombucha's anti-microbial activity" and also to see if drinkable levels of unfermented tea carry anti-microbial properties.

Some of the MATERIALS AND METHODS Greenwalt et al. performed involved the following:

• They tested both black tea leaves (Lovers Leap Orange Pekoe Tea and Pure Premium Ceylon Tea) and green tea leaves (Japanese Sencha Tea and Pure Premium Green Tea) from Metropolitan Tea Company Ltd.
• The tea leaves were steeped for 30 minutes and then removed.
• "The fermentation was terminated at the...pleasing [and desired taste and acidity] of about 33 g/L (3.3%)."
• "The fermentation time averaged nine days at 25°C [77°F]."

After the kombucha tea reach the desired end point, anti-microbial activities were tested against the following organisms:

1. Staphylococcus aureus NRRL B-1317
2. Staphylococcus aureus NRRL B-1318
3. E. coli serotype H10 (non-pathogenic) NRRL B-2207
4. E. coli serotype H48 (pathogenic) NRRL B-3704
5. Salmonella cholerasuis serotype typhimurium NRRL B-4420
6. Bacillus cereus NRRL B-14720
7. Bacillus cereus NRRL B-14725
8. Candida albicans NRRL Y-12983
9. Agrobacterium tumefaciens

"The bacterial species were chosen to represent the most common pathogenic and undesirable organisms associated with food."

The RESULTS of the study:

"The Kombucha colonies used in this investigation had a tendency to produce about:"

• 3.3% total acid
• 0.7% acetic acid
• 4.8% glucose
• 0.6% ethanol
• No lactic acid
• pH ~2.5

Greenwalt et al.'s OVERALL CONCLUSION:

"Kombucha may be a healthful beverage in view of its anti-microbial activity against a range of pathogenic bacteria. This may promote immunity and general well being."

I hope you found the Cornell Study as interesting as I did, and please ask me if you have any questions!

Source:

-Greenwalt, C.J., R.A. Ledford, and K.H. Steinkraus. "Determination and characterization of the anti-microbial activity of the fermented tea Kombucha." Lebensmittel-Wissenschaft und-Technologie 31 (3) (1998): 291-296.

-Online article link here.