Kombucha's Going Mainstream

So I will start off with some good news that I feel that I really should have mentioned long ago- Whole Foods Brighton is now carrying Katalyst Kombucha! Typically I only find GT's brand at Whole Foods stores, so I am very excited about this new (and local) addition!

However, this is not the only recent addition to Whole Foods stores. I had heard the rumors, but was nevertheless still surprised when I found Honest Tea's Honest Kombucha at Whole Foods at the Charles River Plaza.

Yes, Honest Tea has joined the kombucha craze, and is selling three varieties of kombucha at Whole Foods stores: peach mango, berry hibiscus, and lemon ginger.













Don't worry, these bottles are glass, and not plastic.

Even though I brew my own kombucha, of course I had to try a bottle, which cost $3.49 each. I went for the lemon ginger, because I can never miss an opportunity to add more ginger to my life. My opinion: it was too sweet, lacked the vinegar-like taste of traditional kombucha, and was not very fizzy. An 8 oz. serving of Honest Kombucha has 7 g of sugar, compared to GT's 2-4 g sugar or Katalyst's 6 g of sugar per 8 oz. serving. The absent vinegar taste may be missed by some homebrewers, but this could also be a quality to convert that tentative friend. Fizziness is a matter of personal preference, and may be related to the fact that the bottle was not filled up to the top?.

While it's great that Honest Tea's introduction of Honest Kombucha will increase awareness about this drink, I still love the freshness of Katalyst Kombucha and how the taste is reminiscent of a homebrew. And as a local foodie, I am all for my local, independently owned companies. Ideally, though, homebrewing is the way to go for me. It's easy, inexpensive, and fun, gives you a much fresher and sometimes more healthful product, and allows you to tweak your kombucha to however you like it!

Honest Tea is 40% owned by Coca-Cola, and Coca-Cola is expected to buy the other 60% by the end of 2010.

However, Coca-Cola isn't the only large company that has joined the kombucha market.

• Kombucha Wonder Drink is owned by Tazo (launched in 2003)
• Carpe Diem Kombucha was launched in 2007 by Red Bull
• Celestial Seasonings acquired infinitea kombucha this past year

What makes Honest Tea's launch bigger than some of the others is its introduction into Whole Foods, which has a large consumer base and more than 270 stores in North America and the U.K. Typically, I only see GT's at Whole Foods stores, and find other kombucha brands in small health-food stores, co-ops, and the like. Nevertheless, there is yet another fun kombucha addition possibly coming to a Whole Foods store near you: it's said that Townshend Tea's Brew Dr. Kombucha will be available on tap at select Whole Foods stores!

And speaking of kombucha on tap, thanks to the Boston Localvores for informing us that kombucha is also sold on tap at the Concord Food Coop in New Hampshire. Concord Food Coop, here I come!

Enjoy the holidays everyone!

Sources of information (and recommended articles):
Forbes: Kombucha: Can This 'Cure-All' Help Boost Beverage Sales?
World Tea News: Kombucha Not Just for Hippies, but Is It for You?

End of Part 2 of Experiment 2! "Cutting the Kombucha Mother"

The cut kombucha mother again pulled through! After 9 days of fermentation at around 73.4 - 75.2 degrees Fahrenheit, this odd-looking fellow had developed.

So what I have failed to mention before is that sometimes, the new kombucha mushroom that forms is inseparable from the mother.

If this is the case, you can just continue brewing with the kombucha mother and baby mushroom together.

day 9

Although the new mushroom that formed this time does not have an even thickness and is not perfectly shaped because it is still attached to the cut kombucha mother, it still came out cream colored and fermented the 6 cups of kombucha very well!

day 7

day 5

The kombucha from the cut SCOBY had a pH of around 2.5-3.5, and it was very tasty and very comparable to the kombucha that was brewing alongside it with a whole SCOBY!




Overall Conclusions from Experiment 2:

• Cut kombucha mushrooms can ferment various ranges of kombucha tea. (Here, a cut kombucha mother with an area of ~28 cm^2 was able to brew 1.5 and 6 cups of kombucha effectively).
  
• Cut kombucha mothers (1) are able to grow whole mushrooms and (2) can grow into whole kombucha mushrooms, according to the size of the surface area of the brewing vessel (if the old and new SCOBY are inseparable)

A reminder as to why you would want to cut your kombucha mushroom:

1. To increase your brewing capacity by brewing in more containers
   
2. According to this thread, cutting SCOBY's instead of peeling them is better, because each SCOBY layer contains different organisms
   
3. The most important reason of all: to share the joy of kombucha brewing with your fellow fermenters! :)

Koffeebucha, Part 1

Having been a barista for several years, coffee has gone from being a beverage that I enjoy on occasion after a good meal (or a long night), to a necessity. While I understand the potential health drawbacks of my daily habit, I have come to accept the fact that coffee will always be part of my morning routine. I’ve tried to make up for my habit in other ways: getting enough sleep (when possible), fitting exercise into my daily schedule (I commute either by bike or walking on a regular basis), and drinking kombucha.

I’ve been drinking and brewing kombucha for about as long as I have been drinking coffee, so when I recently learned that it is possible to brew kombucha with coffee I had to give it a try!

Following a recipe suggested by a thread on www.kombuchatea.tribe.net, I brewed a full pot (my coffee pot makes 10 cups) of the Organic Coffee Co. Zen Blend coffee. I used 1 tblsp of coffee per 2 cups of water. While the coffee was brewing I poured 1 ½ cups of organic turbinado sugar into my brewing vessel, after sanitizing the vessel with warm water and vinegar. Once the coffee was ready I poured it into the vessel and added two extra cups of warm water, stiring to dissolve the sugar into coffee. After all of the sugar appeared to be dissolved I let the mixture cool overnight to room temperature before adding my scoby. Cooling overnight also allowed my scoby to warm up to room temperature (I normally store my scoby in the fridge when I’m not brewing), so that it did not got into shock when I added it to the brew. In the morning I added my scoby to the koffeebucha mixture, and covered the brewing vessel with an extra coffee filter that I had lying around (consequently, this is also what is recommended by Kombucha Fuel).

The directions I was following suggested that koffeebucha takes longer to ferment than the usual 8 to 10 days, so I plan on leaving my brew fermenting for about 14 days before sampling. I am curious to see what it tastes like!

Day 3, Part 2 of Experiment 2: Cutting the Kombucha Mother

This is what my kombucha looked like after 3 days of brewing 6 cups of kombucha tea with a cut kombucha mother. The tea is brewing comfortably at around 73.4 - 75.2 degrees Fahrenheit.

Day 3

I have to admit that when I first saw the funny looking conglomeration forming at the surface, I was a little concerned that contamination may have occurred. But, these should just be the culture strands gathering to form a new mushroom at the surface, and the other fermentation vessel (below) that I brewed at the same time looks completely normal, so I don't think that the brew should have gotten contaminated.

To be continued!

Day 3 of brewing with a Whole SCOBY

Workshop, Potluck, and Tasting: Featuring Kombucha, Beer, and Wine!

Thanks to everyone who came to my last workshop in October, we had a great turnout! And a big thank you to Abram, who brought several kombucha mushrooms that I was able to distribute!

My next workshop will be with The Urban Homesteaders' League.

What: UHL Holiday Potluck + Kombucha and Winemaking Workshop + Local Brew Tasting
When: Saturday, December 12, 6-9 pm
Where: Allston/Brighton/Brookline-ish area, location will be e-mailed to those who RSVP
Cost: $10 (to cover the costs of supplies and drinks)
RSVP: at the UHL's website
(note: you need to join the UHL to RSVP, but you can always leave the group after the event if you want to)

Learn how to make fruit wine and how to brew kombucha tea, taste several local beers, and share delicious food, all amongst good company and just in time for the holidays!

I will cover the basics of brewing and bottling kombucha, the traditional and continuous brewing methods, how to grow your own kombucha mushroom, and more. Samples of home-brewed kombucha tea will be provided, and SCOBYs will also be available for individuals to take home. RSVP information and the full event description can be found here. It's going to be fun!! Please join us and hope to see you there!

Experiment 2, Continued: Cutting the Kombucha Mother

I am happy to say that I was successful in growing a full SCOBY from a cut kombucha mother! However, this is only the beginning.

The cut kombucha mother (on the right) and newborn SCOBY (on the left) after 9 days of fermentation and around 1.5 cups of kombucha brew.

Day 9

The kombucha segment was a quarter of a SCOBY that had a radius of around 6 cm. So, the area of the cut kombucha mother was around 28 cm^2. Meanwhile, the new SCOBY that it grew had a radius of around 4 cm, with an area of around 50 cm^2 (the area of a circle = pi*radius*radius). The thicknesses of the cut kombucha mother and the new kombucha mushroom were both around 1/8-1/4 in (.32 - .64 cm), and the final brew had a pH of around 2.5-3.5.

Day 8

In his book, I found that Gunther Frank advises to cut kombucha mothers into pieces of around 6 cm in diameter (p. 86). And one experiment performed by the two Russian scientists Sakaryan and Danielova (1948) in Frank's book touches on the subject of the quantity of kombucha culture in relation to the volume of kombucha brew (p. 89-90):

• Five glass containers of the same size were filled with 100, 250, 500, 750, and 1000 mL of nutrient solution, and equal pieces of kombucha culture were put in each of the containers
• On the 5th, 8th, and 18th day, all of the containers had equal pH values
  
• On the 8th day, the container with 100 mL of nutrient solution had the most activity against disease bacteria, while the other samples with varying amounts of kombucha brew were equally effective against disease bacteria
• Conclusions from the study: the activity against disease bacteria is almost independent to the volume of kombucha brew. While different strengths of antimicrobial activity may be more apparent during the first couple of days of fermentation among kombucha brews of varying volumes, these differences in antimicrobial activity may be evened out over longer periods of time of 8-18 days.
• Frank's conclusions: Because there doesn't seem to be an advantage in putting large amounts of kombucha culture in one container, it is advised to part with older cultures over time, "always to use one of the youngest," and there's no advantage to being excessive.

What do I do?

• I typically brew with 1-3 mushrooms in a container, depending on the size of the container, the volume of brew, and the thickness of my mushrooms. I have found that my kombucha mushrooms don't appreciate being very crowded, and you will learn to make your own adjustments with experience!
  

Day 5

Nevertheless, I realized that the kombucha baby that I grew wasn't that much bigger than it's kombucha mother. In addition, the cut kombucha mother was only fermenting a small volume of brew, around 1.5 cups. So, I decided to take on Part 2 of Cutting the Kombucha Mother! This week, I will be brewing 6 cups of kombucha tea with the same kombucha fragment that I used last week (area: 28 cm^2), and in a bigger container with a diameter of 12.5 cm. (So, the new kombucha mushroom that grows should have an area of around 122.7 cm^2). Stay tuned!











Source:
Frank, Gunther W. Kombucha - Healthy beverage and natural remedy from the Far East. 4th ed. Austria: Wilhelm Ennsthaler, 1994.

Exp. 2: Cutting the Kombucha Mother - Day 2

Into Day 2 of Experiment 2, Cutting the Kombucha Mother, and the new mushroom that's forming seems to be looking good! I am currently brewing in my kitchen cupboard, which is a warmer area in my apartment because of my increased tendency to cook during the cooler months. That, in addition to the fact that my roommate does not like the cold so most of our windows are closed, contribute to the kombucha brewing comfortably at super toasty temperatures of around 76-85°F (Which SCOBYs like!).

"Ideally," you brew at around 75-85°F at a constant temperature. Increased temperatures speed up the brewing process, while colder temperatures mean that your brew will take longer to ferment.

Despite the unevenness of the new SCOBY that is forming on the surface, that is not uncommon for the fluctuating temperatures and fluctuating conditions that accompany home brewing, and I don't think it will be a reason for concern. But we will see how the new mushroom develops further over the next few days.

Happy Friday!

Experiment 2: Cutting the Kombucha Mother

The question is: Can you cut your SCOBY?


Due to increased demands for Kombucha mushrooms and also because of personal interest, I've begun to research if you can brew with a segment of a kombucha mother. This site and this discussion thread indicate that it's ok, and that Kombucha mushrooms are made of many microorganisms that replicate when cut. In fact, this thread even recommends cutting kombucha mushrooms rather than peeling off layers, because each layer contains different organisms!
















So, I took the task of cutting a kombucha mother into four quarters. I brewed the batch as normal, putting in just a SCOBY segment rather than a whole mushroom, and we'll see what happens! Look forward to upcoming posts on the development of this brew.

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.

Cornell Study - Part I

Hello all! Things have been crazy busy here as usual- I recently started two new jobs and am still interning with the fabulous program CitySprouts for the summer. But, I was finally able to dedicate a night to post! As a heads up, I will probably be updating my blogs around once a month. I wish I could do more, but I do need to eat and sleep! ;)

In any case, today's post is devoted to Cornell's study on Kombucha Tea- "Determination and characterization of the anti-microbial activity of the fermented tea Kombucha" by C.J. Greenwalt, R.A. Ledford, and K.H. Steinkraus. Published in 1998, this study is one of the most frequently recognized and referred to studies on kombucha tea at the moment. You can see a reproduction of the article here, but my plan is to break the study down for you in a more reader-friendly format and to highlight several of the important points.


I've separted my posts on the Cornell study into two parts- today's post, Part I, will focus on the literary research Greenwalt et al. performed before conducting their experiment. My second post on this study, Part II, will be dedicated to the findings that Greenwalt et al. made after performing their study.

Through Greenwalt et al.'s literary research, they first acknowledge the kombucha craze present in the media, including a New York Times article published in 1994 and a past article in the Miami Herald. Such articles "[suggest] that Kombucha consumption can reduce blood pressure, relieve arthritis, increase the immune response, and cure cancer."

In addition, as indicated by a study performed by Mayser et al.:

• Acetobacter xylinum has been shown to be the primary bacterium in kombucha
• Meanwhile, the yeast composition is highly variable
  
• There was "a low rate of contamination from harmful [spoilage and pathogenic] microorganisms" to the kombucha colonies
• Thus, "Kombucha can safely be prepared at home without pathogenic health risk"

According to a previous paper done by Greenwalt, "Antibitoic activity of the fermented tea Kombucha":

• The acidity of kombucha tea, at ~33 g/L total acid or 3.3%, is pretty high, which limits the ability of many other unfavorable organisms to grow.

In the fermentation process of brewing kombucha tea, the yeast break down:

• Sugar -> glucose + fructose (Roussin, M.R.)
• Glucose-> ethanol + CO2 (Asai)

Meanwhile, the principal bacterium Acetobacter xylinum oxidizes/converts:

• Ethanol -> acethaldehyde -> acetic acid (Asai)
• Glucose -> gluconic acid (Asai)

Although the yeast and bacteria break down much of the sugar in the form of glucose, kombucha tea still contains a little bit of sugar, and most of this is in the form of fructose, which the yeasts and bacteria use less of.

The Acid Composition of Kombucha Tea is approximately:

• 33 g/L (3.3%) total acid (Greenwalt)
  
• 20 g/L (2%) gluconic acid (Steinkraus)
  
• 10 g/L (1%) acetic acid (Petro)

Furthermore, Toda et al. demonstrated that unfermented tea at high concentrations inhibited several pathogenic and undesirable organisms, including seceral strains of Staphylococcus, Salmonella, and Shigella.

And, in various and previous studies, it was determined that high levels of unfermented tea have anti-microbial effects. But, it "has yet to be shown if drinkable levels [of unfermented tea] have similar properties."

Look for Part II of this post (hopefully within a week) on what Greenwalt et al. discovered from performing their experiment on kombucha tea! Their mission for the study: "to determine and characterizie Kombucha's anti-microbial activity using an absorbent disc method," and to also see if drinkable levels of unfermented tea carry anti-microbial properties!

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.

Kombucha: Gourmet Style and City Feed & Supply

A number of individuals have been asking me whether or not I have eaten a kombucha mushroom.

So one day when I had one mushroom too many, I finally decided to try it!

My comments: it was chewy, sticky, and the texture reminded me of the cold Chinese appetizer jellyfish noodles (which I actually really like!).

Photo: courtesy of Chow Times

However, the SCOBY that I had was somewhat old (I would say it had gone through 5+ cycles). And I have found that for consumption, the mushrooms get tougher with age, so the younger, more lightly colored mushrooms are easier to eat.

I am not sure if I will be eating another kombucha mushroom again. However, a friend recently gave me the idea of blending a SCOBY in a smoothie, which is something that I may need to try.

Happy Herbalist lists a number of different ideas and recipes for what to do with your kombucha mushrooms and tea, including using a kombucha mushroom as shoe leather or a drum skin, and using kombucha tea for marinades and even foot soaks.

Photo source: Happy Herbalist

You can also feed kombucha mushrooms to your dog, or composting them is another great option.

Oh yes, and another kombucha find: GT's Kombucha is sold at City Feed and Supply at 672 Centre St., Jamaica Plain! (I do not know if it's sold at their Boylston location, however). A bottle of GT's Kombucha from City Feed will set you back $3.99.

Have a good week, everyone! And thanks for reading!

New Kombucha Discoveries Around Town

One or two weeks ago I found myself at Cambridge Naturals- and I was very happy to find that they did not only have Katalyst Kombucha and GT's as I remembered. They had those two brands, Kombucha Wonder Drink, and High Country Kombucha Tea as well! And although it's hard to see in the picture- just like the Harvest Co-Op, Cambridge Naturals also sells Katalyst Kombucha in a 1/2 gallon jug! (The jugs are in the bottom right of the picture, partially obscured by the boxes).

Later on that week I was at the Harvest Co-Op, and made another good finding: Katalyst Kombucha now sells their kombucha tea in 16 oz resealable bottles! The only downside is that they used to sell 12 oz bottles of kombucha tea for $2. Now at the Harvest Co-Op, they sell 16 oz of kombucha tea for $2.79. $2.79 is still the cheapest price I've found for a 16 oz bottle of kombucha tea in the area, though, at regular price (I think)! And yay for reusable bottles!












Oh, and did I mention that GT's now uses plastic bottle caps for their kombucha tea? No more worries about rusty bottle caps->these bottles are also wonderfully reusable! Awesome. I've seen this brand for $3.49 regular price at Whole Foods and the Harvest Co-Op.

To top it off, I found another location that sells Kombucha Tea- Oh Naturale in Boston's North End (28 Parmenter St.). Oh Naturale is a small health foods store, and sells High Country Kombucha and GT's Kombucha Tea (you can see them in the picture in the bottom three rows). Unfortunately, Oh Naturale sells kombucha at the higher price of $3.99 per bottle.

So I am very happy to say that both the Harvest Co-Op and Cambridge Naturals are equally competitive locations for your Kombucha Oases if you live around Boston/Cambridge. (Something to keep in mind though is that Cambridge Naturals is in Porter Square, while the Harvest Co-Op is in Central Square and Jamaica Plain). Both stores sell all four brands of kombucha tea. However, I sadly did not compare the prices of kombucha tea for either of them, because apparently I was too occuppied with my other good finds. I also do not pay enough attention to the prices, because I find it hard to justify myself to buy kombucha tea when I brew it myself. But the next time I am in these shops, I will be on the lookout for good deals! :)

And if you haven't already, read more about other places in the area to buy kombucha tea in my old post.

For those of you who have Monday off, enjoy the long weekend!!!

The Continuous Brewing Method - Part II - Advantages & Disadvantages

Hello everyone!

My apologies, but handing in job applications and seeing Michael Pollan (!!!) at the West Roxbury Branch Library got in the way of my posting the past few days.

I promised that I would talk about some of the advantages and disadvantages of the continuous brewing method, so here it goes.

PROS of the Continuous Brewing Method

• It's quick & easy
• You have kombucha tea continuously on hand
  
• Less/no sanitizing
• Decreased bottling time
• Decreased mold risk (SCOBY stays in brewing vessel)
  
  -Because you are drawing off how much KT you would like to drink/bottle each day, and because the SCOBY is constantly in the same container, the amount of time you need to sanitize the equipment/area is significantly less. This will save you time and decrease the chance that your SCOBY will become contaminated by mold (even though contamination by mold is rare, anyways- next post!).

• Health Benefits
  -According to Happy Herbalist, the continuous brewing method produces the "fullest most complete range of beneficial nutrients available at any one time."
  -Kombucha researcher Mike Roussin indicated that some beneficial acids do not even appear until 14-21 days of fermentation (1).
  

However, there are several CONS to the Continuous Brewing Method.

• The beverage dispensers that I found in stores had plastic and metal spigots, both materials of which can leach contaminants into the tea when they remain in contact with acid/kombucha tea. This is the very reason why I do not use the continuous brewing method (yet). But:
  
  -Maybe the continuous brewing vessels sold on kombucha websites are specifically designed to avoid this problem? (They are $, however).
  -Some people say to "pick your poison," plastic or metal.
  -*Potential solution!* - Someone at my last workshop had the idea of brewing kombucha tea in its normal container, and then using the continuous brewing method by just siphoning off the liquid from the top. What a great idea!! Hm...I may need to try that soon...

• You won't be producing any more kombucha babies by this method, which may or may not be desirable. I also don't know how long SCOBYs live- some say 8 cycles, some say they last for months- it will depend on many factors. But case in point: kombucha mushrooms do not live forever.

If you would like to read another take on the Continuous Brewing Method, look here.

And remember- whether you decide to use the Continuous Brewing Method or brew the typical way, it all just depends on you and your lifestyle!

Happy Friday!!!

Sources:
-http://www.happyherbalist.com/continuous_brewing.htm
-http://getkombucha.com/
-Photos: http://www.happyherbalist.com/index.asp?PageAction=VIEWPROD&ProdID=123 and http://getkombucha.com/porcelain.html