“Kom-booka, koom-basha, kum-baka?” Whether or not you can pronounce it, Kombucha (kom-bOO-cha) tea has been popping up in grocery store coolers everywhere. Restaurants and cafes are even offering it on tap. As a nutrition student, I frequently get questions regarding this mysterious fizzy drink. To satisfy my own curiosity, I’ve started making my own! But, before we start to brew, it’s nice to know a little background information.
Briefly, kombucha is a fermented tea containing live and active cultures, making it a source of probiotics. In fact, these little bacterium are the reason it has gained such popularity. Kombucha on its own is advertised with a by no means short list of proposed health benefits. A small selection of those claims include:
- Improved Digestion
- Weight Loss
- Increased Energy
- Cleansing and Detoxification
- Diabetes Management
- Reduced Joint Pain
- Cancer Prevention
As someone who is a big fan of the drink, it’s tempting to believe that it really is a wonder tea. But any google search for scientific evidence supporting most of these claims will turn up short. Probiotics in general are being studied for their health benefits and are largely still a mystery to many health and science professionals. Studies on probiotics, from any fermented food (kombucha, yogurt, sauerkraut, kefir, etc) are found to be beneficial for digestion and can help improve immunity. To those claiming kombucha to be anything more than a rich source of probiotics may be exaggerating. That doesn’t go without saying that probiotics are certainly a good enough reason to try this funky, fizzy tea.
The magic behind making kombucha is in the SCOBY or “symbiotic culture of bacteria and yeast”. It has other names like mushroom, mother, starter, or fungus, all of which refer to the same bacteria and yeast living-organism. The disc-shaped SCOBY floats on top of a sweetened tea mixture and ferments the sugars to create acetic acid, carbon dioxide and a small amount of alcohol, usually less than 0.5% ABV. If a tea does have more than 0.5% ABV at the time of sale, it will be labeled with an alcohol content warning. Most kombucha will not have enough detectable alcohol. Depending on the length of fermentation and temperature, alcohol content can creep up. For home brewers, it shouldn’t be a worry unless you plan to distribute and sell your teas. If that is the case, you might want to do more research on becoming an established brewer.
At the end of fermenting, you end up with a fizzy, tangy drink and a “baby SCOBY” that grows in the process. If you’ve ever taken a look at organic, unfiltered apple cider vinegar, you may notice something called “the mother” floating at the bottom of the bottle. Prolonged fermentation can result in complete sugar metabolism to acetic acid, or vinegar. This tangy, acidic flavor is the main reason kombucha tea may be an acquired taste.
With the growing popularity of kombucha (and similarly growing prices), a practical and easy alternative is to make it at home. Home brewing kombucha is low-cost and allows you to control the type and amount of flavorings, as well as how acidic it tastes. There is also the bonus of being able to show off your new hobby to friends and family! The most complicated part of home-brewed kombucha is snagging a starter SCOBY. If you know someone already brewing, they will most likely be enthusiastic about gifting you one of the many SCOBYs they have collected. If you are the first of your friends to trail blaze into kombucha brewing, you can purchase a low-cost SCOBY starter from a local natural foods store, home brewing shop, or even online.
- 1 glass jar (quart, ½ gallon or gallon depending on how much you’d like to make) with lid.
- 1 clean thin kitchen towel or recently washed old t-shirt and large rubber band
- 1 SCOBY
- distilled white vinegar
- 2-8 back tea bags, free from additional flavors and essential oils
- 1/3 cup to 3/4 cup of granulated sugar* depending on the size of your desired batch
- *do not attempt to substitute with honey, agave or other table sugar alternative. White, cane sugar is the SCOBY’s preferred food. Some home-brewers swear by only using organic cane sugar, but conventional will do.
Wash all brewing tools with hot water and distilled white vinegar and let air dry. Detergents and soaps can disrupt the fermentation process and possibly kill your SCOBY.
Heat the desired amount of water and sugar for your kombucha batch (see chart below), stirring until sugar is dissolved. Turn off heat and steep your tea bags to desired strength. Once tea is brewed, remove bags and cool to 65-85 degrees (lukewarm). Then pour tea into glass brewing jar.
|batch size||water||sugar||tea||distilled white vinegar|
|quart||2-3 cups||¼ cup||2 bags||½ cup|
|half gallon||6-7 cups||½ cup||4 bags||1 cup|
|gallon||13-14 cups||1 cup||8 bags||2 cups|
With clean hands, place the SCOBY with distilled vinegar into lukewarm tea. If your SCOBY has been stored in the refrigerator make sure it has reached a similar temperature. Failing to do so may shock the SCOBY and either prolong fermentation or kill the SCOBY. Your SCOBY should float to the top of the jar. If it sinks, don’t panic! Sinking may be because there was too big of a temperature difference between the SCOBY and the tea. It should float back to the top in a few days.*
*If not, monitor for mold growth as it may be a dead SCOBY and you will have to start over with a new one.
Cover the top of the glass jar with a thin towel or clean cotton t-shirt and secure with rubber band. You want to make sure air can still get in for the SCOBY to “breathe” but you want to keep dirt, mold and fruit flies from forming. Place the jar in a warm, dim place for 7-30 days depending on the temperature of your home, and how sweet/acidic you want your kombucha.
Longer fermentations will decrease the amount of sugar left in your tea and make it more acidic. It is good to taste-test every 7 days with a clean straw and determine if you want to keep fermenting or not. Just move the SCOBY over to fit a straw in, you won’t hurt it.
Once fermented to desired taste, remove the SCOBY and its new baby (remember you now have two!) along with enough kombucha tea to keep both submerged in a glass jar. Place them in the refrigerator or one SCOBY directly into a new batch of room temperature sweet tea to begin another ferment. If possible, it’s always great to pass a SCOBY forward to a friend to start brewing their own!
Once the SCOBY is removed, place the lid on the glass jar a seal tightly. Let the jar sit for another few days to allow the yeasts left in the bottom of the jar to keep creating carbon dioxide. This will create the fizz and bubbles most of us enjoy. This is called the “second ferment”.
If you want to flavor your kombucha this is the time to add fruit slices (without the skin or rind) to let the flavors infuse. Some of my favorite flavors include:
- Kiwi and blueberries
- Ginger root and orange
You can also add fruit juices, herbs and additional sweetener to alter the taste of your kombucha. Keep in mind that if you are choosing to do a second ferment (rather than just flavor and refrigerate right away) additionally added sugars will continue to metabolize and lose some sweetness. Kombucha is best when enjoyed cold. Heating will likely destroy any of the beneficial enzymes and nutrients in your tea.
After a week of second ferment, place your kombucha in the refrigerator. You can either remove the fruit slices or leave them in to continue infusing and remove before drinking. Some brewers like to separate the large batch into smaller jars or recycled glass bottles to store and pass onto friends. Each kombucha batch will keep in the refrigerator for 1-2 months but you may notice the effervescence start to diminish after a few weeks.
Enjoy and keep brewing as you learn with each batch!
Here are some additional resources for kombucha trouble-shooting and ideas:
“Wild Fermentation” or “The Art of Fermentation” by Sandor Ellix Katz