Kombucha Demo on March 21

I am happy to announce that my next kombucha demo will be on Monday, March 21, from 7-8 pm in Brookline, MA. For more details and to RSVP, please go to the event page on the Urban Homesteaders' League. If you have any questions about the event, please e-mail me at kombuchafuel [at] gmail.com.

Hope to see you there!

Keeping the Kombucha Brew Warm

It's been a pretty cold and snowy winter this year in Boston, and because the house that I'm currently living in is on the chilly side, I finally decided to purchase a seedling mat for my brew!

Ideally, kombucha brews at around 74 - 84 degrees F. According to Happy Herbalist, the warmer temperatures produce a "faster more consistent ferment while the lower temperatures produce a less harsh more mellow taste though more inconsistent and with a greater susceptibility to molds and pathogens forming. Kombucha brewing seems to work better in the summer than in the winter months."

I agree that kombucha brewing works much better during the summer months than in the winter. So to keep my kombucha warm, I purchased this seedling mat from Amazon. The mat, which you plug into an electric outlet, is supposed to warm the area about 10-20 degrees F above ambient temperature. Although the kombucha and SCOBYs still don't seem to be as happy as they typically are during the summer, the seedling mat has definitely helped!

Other ideas to keep your kombucha warm:

• Brewing your kombucha in a warm (but undisturbed) location, such as in a kitchen cupboard
• Brewing the kombucha in a cabinet with a light bulb (as recommended by Happy Herbalist)
  
• Using a heating pad
  
  

What do you do to keep your kombucha warm?

Next Kombucha Demo: Jan. 31

My next Kombucha Demo will be one week from today: Monday, January 31, from 7-8 pm in Brookline.

For more information about the demo and to sign up, please go to the event page on the Urban Homesteaders' League here.

Hope to see you there!

Kombucha Back on the Shelves

Here is a much delayed follow-up on the Kombucha Recall!

Earlier this year, there was a Kombucha Recall in many stores. This was not a quality issue, but it was due to the alcohol content of kombucha. For a beverage to be sold as a non-alcoholic beverage, the alcohol content must be under .5%. Because kombucha can reach alcohol levels of around 2-something % due to the fermentation process, many brands of kombucha were taken off of store shelves in June because they did not meet the < .5% alcohol content requirement of a non-alcoholic beverage. I read about one company's reaction to the recall on Kombucha Kamp. Because CEO David Koretz, founder of Vibranz Kombucha, had a background in wine-making and expertise in fermented foods, after the recall they were able to reformulate and get their kombucha back on the shelves in only two weeks!

Although not all of the kombucha companies were able to respond to the recall as quickly, it is good to see that numerous brands of kombucha are back on store shelves again. However, some may notice that the kombucha does not taste quite the same as before. How did the companies get the alcohol content to below .5%? Below are some possibilities of how to reduce the alcohol content of kombucha. Please note that I don't actually know what each company is specifically doing to reduce the alcohol content of their kombucha- they may be doing one, several, or none of the options that I list below.

Before I list the various methods, a reminder about the fermentation process: Kombucha is fermented with a SCOBY, also known as a symbiotic culture of bacteria and yeasts. The yeasts convert the sugars to alcohol and CO2, and the bacteria convert most (but not all) of the alcohol to organic acids, such as acetic acid, and water.

To reduce the alcoholic content of kombucha:

• Pasteurization- this process kills the live cultures in kombucha, so the yeasts can no longer produce alcohol. However, through this method, you are losing the benefits of having live cultures in your beverage. Fortunately, it seems that the brands that produced raw kombucha before the recall have decided to continue to stay raw and unpasteurized.
• Earlier expiration dates- refrigeration slows down the fermentation process significantly, but not completely. If the yeasts are still living while the kombucha is in the fridge, they can continue to produce alcohol. Earlier expiration dates help to ensure that the alcohol content won't reach .5%.
• Altering fermentation methods- this includes numerous methods. For example, as you can see from this chart, the alcohol content varies according to the amount of time the kombucha ferments. By altering the amount of time that you brew your kombucha, you can affect the alcohol content of your brew. However, numerous other factors affect kombucha, its alcoholic content, and its rate of fermentation, including temperature, amount of starter used, which strains of bacteria and yeasts are in your brew, etc.
  
• Favoring the bacteria in your SCOBY- this can also be done using various methods. For example, the sediment that is present at the bottom of your fermentation vessel contains yeasts/dead yeasts cells. By filtering these yeast cells out, you are favoring the bacteria, and not the yeasts, which produce the alcohol.
• Diluting the kombucha with water- not ideal, and I'm not sure if any companies actually do it, but it's another possibility.
  

More methods suggested in this Kombucha Kamp blog post featuring Ed Kasper of Happy Herbalist include (read the post for more details):

• Removal of alcohol (such as in the production of non-alcoholic wines)
  
• Know your yeasts! Select specific yeast strains and exclude the yeasts that contribute to higher alcohol content

In addition, here is a link to a podcast where you can listen to (and read the transcript of) Hannah Krum of Kombucha Kamp talk to GT Dave of GT's Kombucha about his product returning to store shelves. (Please note that this interview was before GT's Kombuchas returned to store shelves). According to this interview, GT Dave says that they were not going to change their kombucha formula nor dilute their beverage. And in this blog post, you can read more about GT's two new kombucha lines: the "Enlightened" line with less than .5% alcohol, and the "Full Strength" kombucha line, which contains over .5% alcohol- even though it may take some time before you see the "full strength" version in your area.

Although most companies have tried to get their kombucha to below .5% alcohol so that they can continue to sell it as a non-alcoholic beverage, two companies are taking a different approach to kombucha, by combining kombucha and beer: Lambrucha and Goose Island's Fleur.

It's really too bad that kombucha had to be taken off of store shelves not because of a quality issue, but because of its alcohol content, which is typically still pretty low at <3%. It's great to see numerous brands of kombucha back on store shelves, but again, the great thing about home-brewing is that you can brew your kombucha to exactly how you enjoy it! If you are interested in beginning to brew kombucha, here are several kombucha brewing recipes to get you started.

Upcoming Kombucha Demonstration in Brookline

The information about my next kombucha demo is provided below. However, due to limited capacity, RSVP is required on the Urban Homsteaders' League Meetup Page here. (You will need to join the group, but you can always leave the group after the demo).

Thanks, and hope to see you there!

Kombucha Demo

Date: Monday, December 13, 2010
Time: 7-8 pm

Location: TBA, in Brookline, MA. Nearby T stops: Harvard Avenue Station stop on the B (green) line, Coolidge Corner stop on the C (green) line
The exact location of the workshop will be e-mailed to participants the night before the event.
Cost: Sliding scale, $15-$30
Description:
Kombucha is a fermented tea traced back to Chinese origins to around 220 B.C. Numerous health benefits have been attributed to kombucha, including curing cancer, reducing blood pressure, boosting the immune system, and aiding digestion. Kombucha is also said to have probiotics and detoxifying effects.
Brewing kombucha is quite easy to do at home, and it's fun! Annabelle Ho, author of the blog Kombucha Fuel, will demonstrate and explain the basics of brewing and bottling kombucha. Topics to be covered include required materials, the traditional and continuous brewing methods, how to grow your own kombucha mushroom, and more.
Samples of home-brewed kombucha tea will be available to taste. SCOBYs will also be available for individuals to take home. For those interested in adopting a kombucha mushroom, bringing a clean, glass pint jar would help to facilitate distribution.
For more information on kombucha and how to brew it, visit http://www.kombuchafuel.com.
__________________________________________________________________________
Annabelle Ho is the author of Kombucha Fuel and has been brewing kombucha for over two years. She is currently an undergraduate student studying nutrition in Boston and is the president of Slow Food BU. Annabelle’s interests include herbalism, gardening, agriculture, and biking.

Simple Brewing and Bottling Instructions

These are my simple brewing instructions that I provided at my demo earlier this year for the Urban Homesteaders' League Market Stand. In addition, I've included my simple bottling instructions. More detailed brewing instructions can be found here, and more detailed bottling instructions are here. In addition, this is a link to a post where I list/link to several other kombucha recipes for more perspective and additional information. There is no recipe that's "right." Every brewer has his or her own style and favorite recipe, so adapt the recipe to what works for you!

My next Kombucha Brewing Demo will be sometime in December. Stay tuned for details, and happy brewing!

BREWING DIRECTIONS

Note: It is recommended to clean the equipment with white distilled vinegar, because of soap’s antibacterial properties, which may harm the bacteria in the SCOBY.

Materials

• 1 kombucha culture (also known as a kombucha mother or a SCOBY)
• 2 black or green tea bags (or around 1 tsp. loose leaf tea) per quart water
• ¼ cup (50 g) sugar per quart water
• ½ cup (4 fl. oz) starter tea per quart water
• Water
• 1 glass jar
• 1 pot to boil the water (such as stainless steel, don’t use aluminum)
• 1 clean cloth or paper towel
• 1 rubber band

Directions

1. Boil the water.

2. Add the tea and allow it to steep for 15 minutes.

3. Remove the tea bags/tea leaves.

4. Add the sugar and stir until it all dissolves.

5. Let the sweet tea solution cool down to room temperature (hot temperatures can kill the SCOBY).

6. Pour the sweet tea solution into the brewing container.

7. Add the starter tea into the brewing container and stir it so that it’s evenly distributed throughout the solution.

8. Add the SCOBY that is also at room temperature (it’s ok if it floats or sinks).

9. Cover the container with the clean cloth and secure it with a rubber band.

10. Put your brewing vessel in a quiet, undisturbed spot.

a. With each brewing cycle, a new baby mushroom typically forms.

b. SCOBYs like warm temperatures and the brewing vessel shouldn’t be moved during the fermentation process, because movement will disrupt the formation of the new SCOBY.

c. SCOBYs prefer warm temperatures and brewing between 75-85 F is ideal, 68-85 F is ok.

11. Leave the tea to ferment for 6-14 days (kombucha ferments more quickly in warmer temperatures, so the 6-14 days is just a guideline).

12. Your kombucha tea is done! (Signs include an apple cider vinegar aroma or taste. Taste is the best indicator; it should taste similar to a slighty fizzy version of apple cider vinegar).

13. Set aside a SCOBY and some kombucha as starter tea for your next brew.

14. Drink your kombucha tea as is and store the extra in the fridge, or consider letting your kombucha undergo a second fermentation in the bottling process.

Tip: When first learning how to brew, it is recommended to brew smaller batches (1-2 quarts). Once you get the hang of it and the kombucha mother has produced new SCOBYs, you can brew larger quantities.

Sources:

• http://www.happyherbalist.com/libraryandresearch.aspx
• http://www.kombu.de/anleit-e.htm
• http://www.kombuchafuel.com
  

BOTTLING DIRECTIONS

Materials

• Kombucha
• Bottles and caps
• Bottle capper (if you are bottling your kombucha in beer bottles)
• Optional: small pieces of cut up fruit, ginger, herbs, or jams to add flavors to your kombucha. The possibilities are endless!

Directions

1. Optional: Add some flavors to your brew by adding little pieces of cut up fruit, ginger, herbs, or jam to your bottles. Smaller pieces are better because they give the yeast more surface area to act on.
2. Fill your bottle(s).
1. I typically leave around 1.5 inches of headroom for a 12 oz beer bottle.
3. Cap your bottle(s).
4. Leave your bottle(s) out at room temperature for 1-2 days, or for week(s).
5. Fill your bottle(s).
1. The kombucha is undergoing a secondary fermentation, which can produce more fizz in the kombucha. The secondary fermentation is also a good opportunity to add different flavors to your brew.
2. Kombucha ferments more quickly at higher temperatures.
3. Typically when I have a batch I try one bottle after a few days, and decide whether the rest of the bottles are ready to refrigerate or require more time to ferment.
4. *PLEASE NOTE* if you leave your bottles out for too long, they may explode due to the buildup of carbon dioxide.
6. Refrigerate the kombucha.
1. Refrigerating the kombucha will cause the yeast and bacteria to go dormant. Fermentation isn't completely stopped, but is slowed significantly.
7. Enjoy and drink your kombucha!

Where to shop: The Modern Homebrew Emporium is great for brewing supplies of any kind. Location: 2304 Massachusetts Ave., Cambridge, MA 02140, T: (614) 498-0400.

Q&A: Kombucha SCOBYs vs. Mothers of Vinegar (MOVs)

Q: If I've grown a kombucha SCOBY or brewed kombucha using unpasteurized vinegar as a starter, do I have a kombucha SCOBY or a mother of vinegar?

A: Today's post is dedicated to kombucha SCOBYs and mothers of vinegar (MOVs). Because of their similar appearance and function, sometimes one can be confused for the other. And if you've grown a kombucha SCOBY or brewed kombucha using unpasteurized vinegar as a starter, do you have a kombucha SCOBY or a MOV? The goal of this post is to address this question and to clear up some of the confusion behind the similarities and differences between these two cultures.

Kombucha SCOBYs are used to ferment a sweet tea solution to make kombucha, and the term "SCOBY" stands for symbiotic culture of bacteria and yeasts. The exact composition of a kombucha SCOBY varies, but here is a sample analysis of a kombucha ferment and a certified analysis of a Happy Herbalist kombucha mushroom. According to Happy Herbalist, the three universal elements in all kombucha mushroom strains are gluconic acid, acetic acid, and fructose.

Meanwhile, mother of vinegars (MOVs) are used to produce vinegar. MOVs are cellulose substances made of strains of Acetobacter (1, 2) and bacteria that produce acetic acid.

Kombucha SCOBYs and MOV's look strikingly similar:

Kombucha SCOBY

Mother of VinegarPhoto source

The similar appearance of Kombucha SCOBYs and MOVs are due to the presence of Acetobacter strains, which synthesize the cellulose structure of both organisms.

According to Happy Herbalist, the difference between kombucha and vinegar is that kombucha has gluconic acid, while vinegar does not.

In addition, according to a study cited in the Cornell study, Acetobacter xylinum converts glucose to gluconic acid in kombucha. In kombucha, glucose commonly comes from sucrose (such as table sugar or evaporated cane juice), which is made up of glucose and fructose. From my research on the internet, it appears that Acetobacter xylinum is a strain that can also be found in MOVs. Additionally, I believe that some vinegars (such as apple cider vinegar) do not contain glucose or gluconic acid because they are made of fruit sugars, which are purely fructose.

Traditionally, if you are brewing kombucha for the first time, and you only have a kombucha SCOBY and no starter tea for your brew, one recommendation is to add a little bit of distilled white vinegar to the brew to help bring the pH down. This can help to prevent spoilage microorganisms from growing in the brew, while encouraging the kombucha strains to proliferate. It is traditionally not recommended to introduce unpasteurized or raw vinegars to your kombucha, which could encourage the vinegar strains and produce a mother of vinegar (3, 4).

Some people are concerned that their kombucha SCOBYs may be MOVs if they used raw unpasteurized vinegar as a starter to grow a kombucha SCOBY or to brew kombucha. First off, I would like to say that I am not a vinegar or MOV expert. However, I believe that even if you grow a kombucha SCOBY using the same method that I used to grow a kombucha mother (except for using raw vinegar as a starter instead of kombucha), and if you are feeding the culture glucose, fructose, and tea, and brewing as how you would traditionally brew kombucha, you should be getting benefits from the beneficial acids produced in the brewing process. Just like kombucha, there are health benefits associated with the consumption of unpasteurized vinegars. My hypothesis is that feeding such a culture grown from raw vinegar could still create a SCOBY, because it seems that there are some similar strains in kombucha SCOBYs and MOVs, and natural yeasts and bacteria in the air would be incorporated in the culture to create a SCOBY, as well. I have tried someone's kombucha before, which was brewed from a kombucha SCOBY originally grown from raw apple cider vinegar, and the kombucha tasted similar enough to me that I would have called it kombucha.

It appears that what truly defines what is kombucha (or if you might not have kombucha) depends on your definition. Again, according to Happy Herbalist, the difference between kombucha and vinegar is that kombucha has gluconic acid, while vinegar does not. Meanwhile, according to the Steve Dickman, the co-founder of High Country Kombucha, what makes their kombucha "authentic" is the presence of the strain Z. Kombuchaensis in their brew (see this video, at around time 1:00).

Similar to yogurt, kombucha strains vary considerably, depending on the environment the kombucha is brewed in (because there are different yeasts and bacteria in the air), the ingredients used, and more. For example, High Country Kombucha lists Gluconacetobacter Obediens, Dekkera Anomala, Dekkera Bruxellensis, and Z. Kombuchaensis on their bottle as probiotics present in their kombucha. Meanwhile, GT's Kombucha bottle lists Lactobacillus bacterium and S. Boulardii as probiotics and glucuronic acid, lactic acid, and acetic acid as organic acids present in their kombucha.

Unless you have a kombucha company or if you are an individual looking for specific benefits related to specific strains and specific acids in kombucha, most people will still benefit from the beneficial acids produced in kombucha even without knowing the exact strains that the brew contains, and whether the kombucha was brewed from a batch made with raw vinegar or kombucha as a starter.

Ideally, if you can get a kombucha SCOBY and kombucha as starter tea when you begin to brew, I would use that. If you only have one or the other, and if you want to be more assured of making purely kombucha strains, I wouldn't add unpasteurized vinegars. But, I wouldn't rule out using unpasteurized vinegar as a starter for your first brew, if you can't get access to raw kombucha as a starter. In addition, you will only need vinegar for the first time that you brew, because after your first batch, you will be using the kombucha from your last batch as starter tea. However, what you choose to use will depend on your situation and what you would like to incorporate in your kombucha.

The only way to be truly assured of exactly what is in your kombucha is to get your kombucha and SCOBY tested in a lab. And I do admit, I would be very interested in testing my home-brewed kombucha to find out exactly what is in there! However, although there are specific health benefits associated with specific strains of probiotics, I believe that most people can benefit from the live cultures present in kombucha, whether they know exactly which strains are in it or not.

This is my understanding of kombucha SCOBYs and MOVs at the moment. If anyone has any additional comments, thoughts, or knowledge on the matter, please share!

P.S. If you are interested in learning more about vinegar and how to make wine vinegar, I really enjoyed this thorough blog post and photos.

Happy brewing!