Kombucha 101


Simple Steps for Brewing Up Your Own Healthful Kombucha

The exact origins of kombucha remain somewhat a mystery though evidence suggests this powerful tonic has been around for several hundreds if not thousands of years. Kombucha is a fermented beverage quite simply made with tea and a "colony" of healthful bacteria and yeast, or SCOBY (Symbiotic Colony of Bacteria and Yeast). While the term bacteria often conjures up fear in modern day western culture, the fact is, your body and most of the world around us is made up of various forms of bacteria and you wouldn't be alive without it!  

Regarded widely as a “health” drink, a source of pharmacologically active molecules, an important member of the antioxidant food group, and a functional food with potential beneficial health properties(1), kombucha has gained huge popularity in the U.S. over the past five to ten years. And, whether you consume kombucha for its purported health benefits or for its refreshing, uplifting and unique taste, brewing kombucha is generally regarded as safe and easy for the home brewer.

What follows is a simple guide to brewing up your own kombucha. It is by no means an exhaustive resource on the subject given there are many more detailed and advanced techniques available for those interested in taking home brewing to the highest levels. In any case, we hope you'll enjoy learning more about brewing this age old tonic and we encourage you to carry on your research into the wider world of brewing techniques. 

The Batch Brewing Process

Here are the basics steps involved in brewing a one-gallon batch of kombucha:


  • 1 gallon (4 liters) purified, filtered or bottled chlorine-free water
  • 24 grams of organic loose-leaf tea
  • 1 cup (200g) organic cane juice crystals or white cane sugar
  • Kombucha SCOBY (obtained from a reputable source such as a natural foods grocer, kombucha brewing company, online, etc.)
  • 1-2 cups (250-500ml) strong starter liquid (aka well-fermented Kombucha, generally supplied with SCOBY purchase)

Note about buying your SCOBY: Acquiring your SCOBY is generally a one time purchase as it will end up multiplying itself many times over during your brewing future. You can expect to pay somewhere in the range of $5-15 for a commercially acquired SCOBY through a local farmer's market, grocer or brewer. Or, check in with a kombucha brewing buddy to get one of their extras.  


  • Pot or kettle to heat water
  • 1 gallon brewing vessel (food safe, lead free glass recommended) 
  • Tightly woven cloth to use as vessel dust cover (note: cheesecloth is too loose)
  • Rubber band 
  • Stirring spoon
  • Bottles with tightly closing lids (e.g., bottle should be strong enough to hold up under high pressure, such as a flip-top, locking food-grade bottle)


  1. Bring one gallon water to proper brewing temperature based on tea type.
  2. Add 24 grams tea leaf and steep a bit longer than when brewing to drink as plain tea (e.g., green tea: 4-5 minutes; black tea: 7-10 minutes).
  3. Once steeped, remove tea bag or pour through mesh strainer to remove loose tea leaves.
  4. Add 1 cup sugar and stir until thoroughly dissolved.
  5. Pour into 1 gallon brewing vessel and let cool to room temperature (75-85F degrees).
  6. Once tea is cooled, add SCOBY and starter liquid to brewing vessel.
  7. Cover with cloth and secure with rubber band.
  8. Store covered vessel out of direct sunlight and in an area having clean and good air circulation (e.g., smoke free; away from strong odors and/or other "fermenting" products).
  9. For optimal brewing, the brewing area should be 75-85F degrees.
  10. Do not disturb the brew for at least the first five days to allow for the SCOBY to create a tight "seal" near the top of the vessel. This helps trap carbon dioxide underneath the SCOBY increasing natural carbonation.
  11. At or after seven days, use a spoon or straw to gather a sample of the fermenting tea to taste. (Gently push through edge of SCOBY to acquire the sample.) The longer it ferments, the less sweet and more sour the brew should taste. In the right conditions (i.e.: controlled temperature), your brew should be ready within 7-15 days. In cooler brewing locations, it may take longer.

Once the desired taste has been achieved, it's time to initiate bottle conditioning and/or second fermentation. This will help to increase natural carbonation and is a good time to add flavors, if desired. 

  1. With clean hands, transfer the SCOBY and about 2 cups of brewed kombucha (gathered from the top portion of your brewing vessel) into a clean glass bowl or jar for your next batch. (If you don't plan to use it right away for another batch, be sure to keep the storage container covered with a cloth, adding more sweet tea as needed to keep the SCOBY happy.)
  2. Fill strong, sealable bottles with brewed kombucha leaving very little room at the top. Once full, seal tightly as contents will continue to build pressure.
  3. Let bottled kombucha sit at brewing temperature (75-85F degrees) for 48-72 hours to build additional natural carbonation. 
  4. Refrigerate and then enjoy. 



What color should my SCOBY be?

  • A SCOBY may start out off-white in color but may become more yellow over time and/or display various shades or spots of brown.

What are the brown stringy things hanging from my SCOBY?

  • Yeast strands or tendrils (generally brownish in color) may droop down from bottom of the SCOBY. Sometimes "globs" of yeast get trapped between layers of the SCOBY causing dark spots to appear in the otherwise translucent SCOBY. 

Is it okay that my SCOBY sank? 

  • A "mother" or starter SCOBY will quite often sink or remain at the bottom of the vessel. However, a new baby SCOBY should begin to grow and form a seal at the top of the liquid.

Is my SCOBY moldy?

  • Mold is largely indicative of something not right in your brewing environment, but otherwise its presence is pretty rare.
  • Mold on a SCOBY looks like mold on virtually any another rotting food item, appearing dry and fuzzy. It is often blue, black or white and would sit on top of the SCOBY. 
  • If mold does appear, dispose of the entire batch of kombucha and start over using a fresh culture (SCOBY) and starter liquid. 

Should I ever refrigerate my SCOBY?

  • In short, no. Cold temperatures (e.g., under 50F degrees) are not recommended for your SCOBY. Keeping your SCOBY in cold storage for more than a few hours may put the necessary acetic-acid bacteria into a "sleep" mode. This can cause the bacteria to be ineffective at protecting the brew and may also increase the likelihood of mold. 


(1) "A Review on Kombucha Tea—Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus", Jayabalan, Malbasa, et al, pub. June 2014

Disclaimers: The information presented on this website is for informational purposes only. Modern Steep does not provide medical advice, nor do we replace the advice or attention of heath-care professionals. Consult your physician before beginning or making changes in your diet, for diagnosis and treatment of injuries and illness, and for advice regarding interactions with other prescribed medications. Any mention or claims regarding health benefits contained herein have not been evaluated by the FDA.  Modern Steep makes no formal claims about Kombucha, but aims to reflect a wide-range of professional and personal views regarding Kombucha’s beneficial properties. Safe brewing and handling practices are the responsibility of any person involved with brewing kombucha or any ingestible product. The information contained herein is NOT intended, nor should it be used to diagnose, treat, cure, prevent, or mitigate any disease or condition. We encourage any party interested in home brewing to conduct their own research into the appropriate methods, safety risks, and best practices prior to any attempt to home brew.