* Please note that this blog remains up as a resource. However, this blog is currently on hiatus until further notice. For more information, please read this blog post. Thank you and happy kombucha brewing, drinking, and SCOBY trading! Lots of love. ~Annabelle *

Wednesday, December 29, 2010

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.

Tuesday, November 30, 2010

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.

Saturday, November 27, 2010

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:

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.

Sunday, October 24, 2010

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!

Saturday, September 18, 2010

Upcoming Kombucha Demo at Galatea Fine Art

My next Kombucha Demo will on Sunday, October 3 from 1 - 2 pm. It will be held at Galatea Fine Art at 460 B Harrison Ave., Boston, MA 02118, conveniently located next to the SOWA Open Market. :)

There are only 15 spots available, so RSVPing on the Urban Homesteaders' League Meetup page is required. (You will need to join the group, but you can always leave the group after the demo). For more details on the demo and to RSVP, please go here.

Hope to see you there!

Friday, September 17, 2010

A Word On: Mold

I have been lucky in that I have never encountered mold when brewing kombucha.

Kombucha has been found to have a low rate of contamination and of mold, and has been found to be safely prepared at home (1). Kombucha's low risk of contamination results from its natural anti-microbial activity, attributed largely to the presence of acetic acid according to the Cornell study (1). Kombucha's low pH also helps to prevent undesired microorganisms from proliferating.

Remember that kombucha mushrooms come in all shapes, sizes, and colors, and colors can range from creamy white to all variations of brown. And if you've never seen the development of a SCOBY completely from scratch, look at my photos from Experiment 1, Growing Your Own Kombucha Mother.

If you do suspect mold, remember that it should appear FUZZY such as the mold you see on bread.

Photos from Happy Herbalist

If your kombucha mushroom does form mold, the safest thing to do would be to throw out that batch and that mushroom, and to brew with another mushroom- another great reason to have a backup mushroom in storage. I've talked to several people who have cut off the mold-infected part of the mushroom and continued to use the rest of the SCOBY, but do this at your own discretion! If imperceptible mold spores are in the rest of the mushroom or in the brew, this could cause problems for the next batch, so you may want to start anew!











More info on mold can be found in Happy Herbalist's Brewing Guide and Kombucha Photos page.

Reference
1. 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.

Tuesday, August 31, 2010

Workshop Recap

Thanks to everyone who took a break from the gorgeous day last Saturday and joined me at the Kombucha Workshop at Taberna de Haro! In addition, thanks to everyone who came from the Urban Homesteaders League- I really appreciate the positive feedback!

Kombucha

Demo

I would also like to thank Taberna de Haro for letting me use the space for the workshop. Read my post on Taberna de Haro on my other blog, Herbal Medicine Box.

It was a good time, and to those who took home SCOBYs, have fun! I look forward to the next kombucha demo.

Happy brewing,

Annabelle

Tuesday, August 17, 2010

Where to Obtain Kombucha Cultures (Updated August 7, 2013)

I've been receiving numerous e-mails about where to buy kombucha mushrooms, so here's a quick rundown of your options.
  • A friend - If you are brewing using the traditional method and conditions are right, you get a new kombucha culture each batch! This means an overwhelming number of mushrooms if you brew regularly. So hit up your friends and tell them to spread the kombucha love! :)
  • My availability: Unfortunately I am unable to provide kombucha SCOBYs at this time.
If you have any more ideas of where to obtain kombucha mushrooms, please share!

Friday, August 13, 2010

Kombucha Workshop at Taberna de Haro

My next Kombucha Workshop will be at Taberna de Haro, the Spanish wine and tapas restaurant in Brookline that I work at! Read my post about Taberna de Haro on my other blog, Herbal Medicine Box.

Date: Saturday August 28, 2010

Time: 3-4 pm

Where: Taberna de Haro at 999 Beacon St., Brookline, MA 02446

Cost: Free, but donations are always welcome

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.

It's not hard to brew your own kombucha at home, and it's fun! I 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.

Hope to see you there!

Kombucha Fuel at the UHL Market Stand Wrap-Up

Thanks to everyone who braved the heat and came by for the kombucha demo at the Urban Homesteaders' League Market Stand in July! Despite the heat, it was a blast!

Check out some photos from the market stand that day (you can't see me or the kombucha, but you can see the crowd!) Also, see the broadside that covers the information covered in the July skillshares at the UHL Market Stand, which include city composting, my simple recipe for brewing kombucha, making jam, and herbal salves. (Please note that in the kombucha recipe, it should read 1/4 cup (50 g) sugar per quart water and 1/2 cup (4 fl. oz) starter tea per quart water).

Thanks again to everyone who came, and keep on reading the Urban Homsteaders' League's blog for upcoming skillshares at the UHL Market Stand! The next one is tomorrow, and the schedule is here.

Tuesday, August 10, 2010

How to Mail a Kombucha Mushroom

Mailing a kombucha mushroom is actually quite simple! To mail a kombucha mother, put the SCOBY in a Ziploc bag, such as the ones you would use for freezing food. Put some kombucha in there as well for the SCOBY to sit in (which can later be used as starter tea), and seal the bag. Put this bag into another Ziploc bag and seal that too, so the SCOBY is double-sealed. Put this package into a box with some good cushioning so the kombucha mushroom isn't jostled around too much (but also leave a little room for the plastic bags to expand because the SCOBY will ferment and produce CO2 during transportation), and you're all set to mail away! (P.S. I've never actually mailed a SCOBY, but numerous readers have confirmed that this works, and Gunther Frank has mailed kombucha mushrooms all over the world this way with much success!)

This can be handy if you would like to mail a kombucha mushroom to a friend, or to mail a kombucha mother to yourself if you are moving and cannot bring your SCOBY on the plane with you.

However, because plastic is not good for the mushroom in the long-term, it is recommended to transfer the kombucha and SCOBY into a clean glass jar once it arrives! Then you can either begin brewing or put the kombucha mother into storage until you're ready to brew.

Tuesday, August 3, 2010

Welcome to http://www.kombuchafuel.com!

Hello wonderful readers,

Thanks for reading my blog and for the continual support, comments, and messages. It's a blast, and the blog would not be the same without you!

I am happy to announce that http://kombuchafuel.blogspot.com is now http://www.kombuchafuel.com! So, if you are currently subscribed for the RSS feed for http://kombuchafuel.blogspot.com, you may need to resubscribe to www.kombuchafuel.com. Other than that, everything is the same, and the old links still work, too! :)

I hope you keep reading, and happy brewing!

Monday, July 19, 2010

Q&A: Why does my kombucha smell like sulfur and/or rotten eggs? Is it safe to drink?

Q: Why does my kombucha smell like sulfur and/or rotten eggs? Is it safe to drink?

A: A rotten egg smell comes from sulfur. The presence of sulfur may be:
Because kombucha and beer are both products of fermentation, the reasons for sulfur/rotten egg smells in beer may be the same for kombucha:
Is the kombucha safe to drink?
According to the threads here and here, it appears that the kombucha is still safe to drink even if it smells like sulfur/rotten eggs. However, if you don't feel good after you drink it, stop!

What can you do?
  • If you think the sulfur smells are due to your water source, consider using a water filter or upgrading your current water filter.
  • Let your kombucha age for longer periods of time before you drink it to see if the sulfur smells decrease over time.
  • If you think the sulfur smells are due to certain yeasts in your kombucha, try favoring the bacteria in your brew.
  • Try cleaning all of your equipment and make sure you practice proper sanitation techniques.
  • Try starting over with a new SCOBY.
If you have had any experiences with your kombucha smelling like sulfur and/or rotten eggs, have any other suggested solutions, or have any success stories, feel free to share!

Wednesday, July 14, 2010

Kombucha SCOBY Exchange on Facebook

There are many ways to obtain kombucha cultures, which I describe here.

I would like to present the Kombucha SCOBY Exchange on Facebook, which is sort of a Facebook version of the Worldwide Kombucha Exchange.

I previously suggested that individuals who were looking for SCOBYs or who had extra SCOBYs to share to write a post on Kombucha Fuel's Facebook wall. However, over time, I found that this was not very effective as the requests and offers got pushed down as people wrote new posts on the wall. I have thus created the "Kombucha SCOBY Exchange" as a note on Kombucha Fuel on Facebook. This way, all of the SCOBY requests and offers are together, making it easier for those who are looking for kombucha cultures to connect with individuals in their area who have extra SCOBYs available.

I hope that this will become a helpful resource, and if anyone has any comments, questions, or suggestions, I welcome them.

Below is a copy of the Kombucha SCOBY Exchange note that I have put on Facebook:


Welcome to the Kombucha SCOBY Exchange!

Looking for a kombucha mushroom?
If you are looking for a kombucha mother, write a comment saying that you are looking for a SCOBY and list your location with as much information as you feel comfortable. If someone with extra SCOBYs in your area sees the request, hopefully they will contact you so you can schedule a pick-up!

Have extra kombucha mushrooms to share?
If you have extra kombucha mothers that you would like to share, likewise leave a comment and list your location with as much information as you feel comfortable. This way if someone is looking for a kombucha mushroom in your area, they can contact you! Also, please don't be shy if someone is already offering kombucha mothers in your area. It can be helpful to have multiple people offering SCOBYs in the same area!

Tips:
-You can delete any of your own comment(s) at any time if your situation or location changes.
-If you find someone to connect with, consider contacting them directly. This will help to keep the Kombucha SCOBY Exchange more clutter free and easier to navigate.

Thank you for participating in the Kombucha SCOBY Exchange, and I hope you find this exchange useful!

Happy Brewing,
Annabelle

Tuesday, July 13, 2010

Kombucha Skillshare and Kombucha Fuel at the UHL Market Stand (Updated July 13, 2010)

*Update: My Kombucha Skillshare is scheduled for 10:45 am this Saturday. Hope to see you there!*
_____________________________________________________________________

Join Kombucha Fuel at the UHL Market Stand at the Union Square Farmers Market on July 17th!

What: Kombucha Skillshare (20-25 minutes) and Kombucha Fuel at the
UHL Market Stand

When: Saturday, July 17th. Kombucha Fuel at the market stand from 9 am - 1 pm. Kombucha Skillshare at 10:45 am (20-25 minute demo).

Where: UHL Market Stand at the Union Square Farmers Market (1 Union Square, Somerville, MA, 02143)

Description:
I will be at the
UHL Market Stand from 9 am - 1 pm, to talk to visitors and answer questions about brewing, bottling, and anything kombucha! At 10:45 am, I will lead a Kombucha Skillshare, covering the basics of brewing and bottling the fermented tea kombucha in a 20-25 minute demo.

SCOBYs will be available for those interested in beginning to brew on their own from 9 am - 1 pm. For individuals interested in taking a SCOBY home, bringing a small, clean glass jar would help to facilitate distribution. In spirit of the swap table at the
UHL Market Stand, bringing something to swap for the SCOBY would be fun, although it's not required. :)

This demo will be in conjunction with the UHL Market Stand of the Urban Homesteaders' League. They are an awesome group! Read about the Urban Homesteaders' League and check out their blog.

There will also be three other urban homesteading skillshares at the
UHL Market Stand on July 17th, see the schedule here.

Monday, July 12, 2010

Bottling and Headroom (Updated July 12, 2010)

***For the update please scroll down to the bottom of this post***

After several readers inquired about leaving headroom when bottling, I felt obligated to experiment.

I had always learned to fill the kombucha all the way to the top when bottling for a secondary fermentation. This stops the activity of the bacteria because of the exclusion of oxygen, while the yeast can continue to ferment the sugars to create CO2 and an effervescent drink, because yeasts can function with or without oxygen (1).

After being prompted to do some experimenting on my own, I left around an inch of headroom in several kombucha bottles for a secondary fermentation. I left the bottles out for a few days, and then I refrigerated them. I didn't open the bottles right away because I already had some kombucha bottles open, but I pulled one out from the refrigerator a week or so later and found that the kombucha bottled with around an inch of headroom was more fizzy than a good number of my previous batches!

Bottling with Headroom
Photo courtesy of Haven Sarah Ripley Daniels

Although Happy Herbalist mentions to fill the kombucha to the top of the bottles in their
Brewing Guide (look under "Bottling"), on their Bottling Tips page there is a section "Choosing to leave an airspace." According to their Bottling Tips page, if you leave oxygen and airspace in the bottle and if the temperatures are between 70-85 degrees F, the bacteria will continue to remain active and the kombucha will continue to sour, which makes sense because the bacteria require oxygen.

Meanwhile, the yeasts can function with or without oxygen. However, according to
Happy Herbalist, yeasts only form carbon dioxide and fizz when oxygen is present (2). "Carbon dioxide suffocates/diminishes the bacteria, but produce[s] the fizz and sparkling brew. Without oxygen the yeast produce more alcohol...The yeast may be active in temperatures as low as 40F (5C) with or without oxygen" (2). In other words, if you leave headspace when bottling, the yeasts can create more carbon dioxide and fizz because of the oxygen present in the airspace. But if there is no airspace, the ability of the yeasts to produce an effervescent drink is limited because of the limited availability of oxygen.

Unfortunately, I was perfectly happy with this explanation until I returned to this formula from my previous post,
Kombucha + Fizz, and could not find oxygen needed in the equation for the yeasts to form carbon dioxide:

The yeasts convert sugar to alcohol + carbon dioxide (3, p. 40)

C6H1206 -> 2C2H5OH + 2CO2
sugar -> alcohol + carbon dioxide

Thus, I am somewhat still confused about the exact relationship between the yeasts, oxygen, carbon dioxide, and kombucha fizz. Perhaps the presence of oxygen helps to encourage the yeasts to form more carbon dioxide and fizz, but its presence is not necessary?

Something to note is that kombucha that is bottled all the way to the top will taste different than kombucha that is bottled with airspace, such as in the amount of fizz produced and in others ways as well, such as the acidity of the drink.

I have not found much information on the recomended amount of airspace if you decide to bottle kombucha this way. However, beer brewers tend to leave 1-2 inches of headspace in their bottles according to this
thread. Again, experimentation is key, and do whatever you prefer according to personal preference and taste!

As always, I am continuing to learn more about kombucha day by day, and I hope to share that information. If you have any more information or tips on the bottling process and kombucha fizz, please send the information my way or leave a comment!


All my posts related to bottling can be found here.

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

***Update July 12, 2010***

I was able to get to talk to a brewer who brews beer and kombucha. Here is what I learned:
  • Confirmation that headroom helps prevent the bottle from exploding from the buildup of carbon dioxide.
  • You can still increase the fizz in your brew whether or not you leave headroom in your bottle.
  • You won't lose fizz by leaving headspace in the bottle.
  • You lose more fizz the more you transfer the kombucha from container to container. You can actually decarbonate your brew by transferring your kombucha from container to container.
In this article from Happy Herbalist, it states that aerobic and anaerobic yeasts in kombucha help to produce carbonation, and that the production of more carbonation than alcohol by both types of yeast is favored when oxygen is present, which is in line with the other Happy Herbalist information (that I am conflicted about) that I provided above.

Part of the reason why there doesn't seem to be a clear answer to the question about whether it is better or not to leave headroom to create more fizz, is because kombucha ferments and SCOBYs contain different strains of bacteria and yeasts and in different proportions. Wild and airborne bacteria and yeasts, which differ according to the location and environment, add even more variation to the mix.
Here is one Analysis of a Kombucha Ferment by Happy Herbalist as an example for what may be in your brew.

I personally prefer to bottle with headroom at the moment. But it is up to you, and based on your experiences, to decide whether or not you want to leave headroom in your bottles. I recommend experimenting with both. If anyone wants to share their experiences with bottling, please do so!

Friday, June 18, 2010

Kombucha Drinks Pulled From Whole Foods' Shelves and On Tap

Whole Foods has removed all raw kombucha products from all of their stores. Although it is well known that kombucha contains trace amounts of alcohol, the products were removed due to concerns with slightly elevated alcohol levels because products containing more than .5% alcohol must be labeled with a warning.

Read some articles on the topic:

Although kombucha can reach alcohol levels of 2-something %, producing kombucha with less than .5% alcohol is possible. For example, Katalyst Kombucha produces a raw, unpasteurized product with < .5% alcohol content. (Unfortunately, their products have been removed from Whole Foods' shelves for the time being as well). Here is a short discussion thread, Why does my kombucha have high alcohol content?!

Luckily, this recent action does not affect those who home-brew kombucha. And for those of you who don't brew your own, now is the perfect opportunity to start!

There are still plenty of places to purchase kombucha around Boston, MA. Check out my Google map on where to purchase kombucha around the Boston area.

It will be interesting to see what happens, and hopefully things will turn out alright. Stay tuned for updates!

Saturday, June 12, 2010

Where to Get Brewing Equipment Around Boston, MA

Need kombucha equipment?

Check out the Modern Homebrew Emporium in Davis Square for all your home-brewing needs (including bottles, bottle caps, bottle cappers, pH strips, and more). I love this place!

Photo thanks to CityVoter

Modern Homebrew Emporium
2304 Massachusetts Ave.
Cambridge, MA 02140
(614) 498-0400

Monday, May 31, 2010

Q&A: When is my kombucha done fermenting? (Updated 5-31-2010)

Q: How do you know when your kombucha is ready to drink, ready to bottle, or if it's done fermenting?

A: If you are brewing using the traditional method, your kombucha may be done at anywhere between 6-14 days. The time may even be more or less, depending on personal preference, the amount and strength of the starter tea you used, and various environmental factors, such as temperature. So how do you know when your kombucha is done? Here is a list of several signs that help to indicate when your kombucha is ready (please note that not all of these need to apply!):
  • According to taste- the most important indicator, as individuals have varying preferences for the amount of fizz, the strength of the sweetness, and the intensity of the vinegar-taste of kombucha
  • Hard apple cider or apple cider vinegar aroma or taste present
  • The kombucha tastes slightly sour or acidic (like vinegar)
  • Kombucha gets more cloudy/opaue, and thus becomes lighter in color, the longer it ferments due to yeast reproduction
  • The partial/complete formation of a new kombucha baby
  • Kombucha is bottled "optimally" at a pH of 2.5 - 3.5 (testing pH is optional)
Note the clearness of the kombucha at the beginning of fermentation (left) and the cloudiness of the kombucha at the end of the primary fermentation process (right). (My apologies if it is hard to tell in this photo).

Note:
  • Home-brewed kombucha tastes a lot different than GT's traditional kombucha. I've found that Katalyst and High Country kombucha taste more similar to home-brews.

Thursday, May 27, 2010

Kombucha + Fizz (Updated May 27, 2010)

Yes, kombucha can be fizzy.

I've been receiving numerous questions about fizz, so here is what I understand thus far on the matter!

To begin, fizz does not indicate the health of your SCOBY or your ferment. Fizz is more a matter of personal preference, and may indicate the balance of yeasts and bacteria in your brew (1, 2).

For the scientific side on the matter, here are the chemical reactions that occur during kombucha fermentation (3, p. 40):

The yeasts convert sugar to alcohol + carbon dioxide.

C6H1206 -> 2C2H5OH + 2CO2
sugar -> alcohol + carbon dioxide

The bacteria convert the alcohol to organic acids, such as acetic acid, and water.

C2H5OH + O2 -> CH3COOH + H20

alcohol + oxygen -> acetic acid + water

The CO2 (a gas) that forms reacts with the water in the tea to produce carbonic acid (think of carbonic acid as dissolved CO2). Carbonic acid is a weak acid that readily decomposes back into water and carbon dioxide. When the carbon dioxide bubbles out of the water, you get fizz (4).

CO2 + H2O -> H2CO3
carbon dioxide + water -> carbonic acid

Carbonation and the primary fermentation:
As the new kombucha mushroom forms at the surface during fermentation, the ability for the carbon dioxide to escape decreases, helping to create some of kombucha's natural
fizz. The more quickly and the more thick your mushroom forms, the less the CO2 will be able to escape, which can increase the carbonation of your drink (3, p. 33, and 5).

A lower
fizz may indicate a lower ratio of yeast to bacteria in your culture. The ratio of yeasts in your brew may be increased by (1):
  • Using the bottom SCOBY from your previous batch
  • Using more of the kombucha at the bottom of your brew, which tends to be more cloudy/yeasty, for your starter tea.
Carbonation and the second fermentation:
  • Fizz can be significantly increased by bottling. My posts related to bottling can be found here.
  • Consider experimenting with leaving and not leaving airspace. Read my post Bottling and Headroom.
  • Adding flavors (such as jams, citrus peels, ginger, etc.) during the bottling process can also help to create more fizz. (Similar to adding a primer in beer making).
  • Beer bottles, which have a very tight seal, are ideal for creating fizz in kombucha. In my experience, when I've used resealable bottles (such as GT's or Katalyst kombucha bottles), I've lost more fizz.
  • -The longer you leave your bottles out for a secondary fermentation, the more carbonation will build up. HOWEVER, if you leave your bottles out for too long, you run the risk of them exploding! Some people recommend 1-2 days for a secondary fermentation, others 3-4 days, and some recommend even longer. It all depends on various factors, including the sugar content of your kombucha and the temperature (higher temperatures = faster fermentation).
    -My advice:
    If you're fermenting a batch, try a bottle after 1 or 2 days (more or less days depending on previous experiences, etc.). Then decide whether your other bottles are ready to refrigerate, or if they could use some more time fermenting.
Some more reading:
Happy brewing!

Sources:
1. http://users.bestweb.net/~om/kombucha_balance
2. http://www.getkombucha.com/spreisfifa1.html
3. Frank, Gunther W. Kombucha - Healthy beverage and natural remedy from the Far East. 4th ed. Austria: Wilhelm Ennsthaler, 1994.
4. http://uk.answers.yahoo.com/question/index?qid=1006051206579
5. http://kombuchakamp.blogspot.com/2009/04/fizzy-brew.html

Kombucha Bottling 101 (Updated May 27, 2010)

What to do when you are done brewing your kombucha? One thing you can do is bottle your brew.


Why bottle?


Bottling, or a secondary fermentation, allows the yeast to feed on more of the sugar in your kombucha tea. This creates CO2, decreases the amount of sugar in your kombucha, and also makes your drink more carbonated and fizzy, which many people enjoy.

Here are some things to think about when choosing your bottle:
Good:
  1. Glass bottles with narrow necks are the most common way to store fermented beverages.
    -old beer bottles* (their tight seals are ideal to create more fizz)
    -EZ Cap (Flip-Top) Beer Bottles
    -wine bottles
    (nice as a gift or if you're sharing!)
    -etc
    .
It's your choice:

  1. Old kombucha bottles-Pro:
    -GT's now sells kombucha with plastic caps! Many kombucha brands now sell kombucha in reusable bottles.
    -Con:-In my experience, they sometimes leak, and air can escape more easily as opposed to beer bottles (air leakage can lead to decreased fizz).-If they came with metal caps (ex. the GT ones), the caps usually oxidize/rust easily

    GT's old metal caps

  2. Old plastic bottles

    -Pros:
    -The plastic material allows for expansion (decreasing the chance of your bottle exploding).
    -The plastic bottles become hard after a couple of days, signaling that the yeast have consumed most of the sugars in the kombucha and that you are ready to refrigerate it.
    -Cons:
    -Plastics aren't good for the environment.
    -Re-using old plastic bottles could expose you to chemicals. (Especially because Kombucha Tea is acidic!)
    -Note:
    -Some people choose to do an initial secondary ferementation in plastic bottles and then transfer the kombucha into glass bottles for long-term storage. More information on this in the Two Stage Bottling Technique at Kombucha Balance.
    -My recommendation:
    -I don't use plastic bottles for my kombucha, but if you do, please re-use a plastic bottle only once!

DIRECTIONS
  1. Optional: Add some flavors to your brew! Put in little pieces of cut up fruit, raisins, goji berries, etc. to your bottle, to add some zing and health benefits to your kombucha! They will provide some more sugars for the yeast to feed on, adding flavors and creating an additional fermentation. It's generally recommended not to add too much biological matter. And the smaller the pieces are, the more surface area that the yeast can act on.What also works well:
    -Citrus fruit peels (ex. grapefruit, lemon, lime, orange)
    -Fresh ginger
    -Jams/jellies/preserves
    Tip:
  2. -If you are using raisins or dried fruit to flavor your kombucha, cut them up first!

  3. Fill your bottle(s).-It is up to you on whether or not you would like to leave headroom. For more info, read my post Bottling and Headroom.

  4. Cap your bottle(s).

  5. Leave your bottle(s) out at room temperature for 1-2 days, 4-5 days, or longer.-Personally, I've been doing 4 days, but the time will vary depending on the brew/brewing conditions (ex. the temperature of the room).
    -*PLEASE* do not leave your bottles out for too long. Otherwise, too much CO2 may build up in your bottle, causing it to explode!

  6. Refrigerate your kombucha!-If you bottled your kombucha in plastic bottles, the bottles should feel hard when it's ready to refrigerate them.
    -Refrigerating your 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! Some people recommend dating your batches, but I always finish drinking my kombucha before the next batch comes around! :)
Note: Like soda, once opened, kombucha goes flat.

*A few comments about beer bottles*:

-If you drin
k beer, this is a great way to use up old bottles!
-They are easy to get for free. You can even get used ones for free (or cheaply) from restaurants, bars, etc.
-If you feel uncomfortable using old ones, you can buy new beer bottles at your local brewing store, although this is the more expensive route.
-Note- clean them well first!!! Go to your local homebrewing store and get a brush to scrub them out a bit. Then boil them, put them in the dishwasher, use Iodophor, or do whatever it is that will ensure removal of any hiding bacteria/places where bacteria can grow!-To cap your bottles, buying bottle caps are relatively cheap. I got a half pound of caps for only around $3-4 at the Modern Homebrew Emporium in Cambridge. And at only $14, the Red Baron Beer Bottle Capper is a good investment. Find it at your local brewing store or online.
-The one downside- I have to admit that going through bottle caps is not the best for the environment. If this is a concern for you, the EZ Cap (Flip-Top) beer bottles, which are refillable, may be the way to go.

Tuesday, May 25, 2010

Q&A: How do you grow a thick kombucha mushroom?

Q: How do you grow a thick kombucha mushroom?

A: Remember that Kombucha Mushrooms Come in All Shapes, Sizes, and Colors! Even if your kombucha mother does not look like a perfectly even 1/8 - 1/2 inch thick cream-colored pancake, it could still ferment your kombucha very well!

If you want a thick kombucha mother, you can put some kombucha in a clean glass jar, cover it well with a breathable cloth, and let it sit for a few weeks until a thick mother grows and develops. Or, you can just let one of your kombucha brews ferment for a prolonged period of time until a thick SCOBY forms.

The kombucha will become pretty strong, sour, and acidic if it has been fermenting for a long time, and using this kombucha as starter tea will favor the bacteria and thick SCOBY formation (1). For other uses of sour kombucha, check out Happy Herbalist's recommendations: Kombucha Tea Too Sour?

Acetobacter xylinum has been indicated to be one of the main bacteria in the colony that helps to form the cellulose structure of the kombucha mushroom (2-3). So to favor a thick kombucha mother, you want to favor the bacteria.

For more information on decreasing yeast to bacteria ratios, which will favor the bacteria and a thick SCOBY, visit Kombucha Balance: Decreasing the Ratio of Yeast to Acetobacter Populations.

References:
1. Kombucha Balance: Decreasing the Ratio of Yeast to Acetobacter Populations
2. 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): 291-296.3. Malbasa, R., E. Loncar, and M. Djuric. "Comparison of the products of Kombucha fermentation on sucrose and molasses." Food Chemistry. 106 (2008): 1039-1045.