All About Kombucha

Today I’d like to tell you all about kombucha. Kombucha is a fermented beverage made out of tea and sugar. Sounds like some pretty unhealthy ingredients but the end result may actually be really healthy.

The tea and sugar are fermented with the help of a so called SCOBY (symbiotic colony of bacteria and yeast). SCOBYs look like some kind of giant mushroom and are therefore also referred to as kombucha mushroom. The bacteria and yeasts in the SCOBY eat the sugar and tea which creates a sour tasting and carbonated drink that reminds me of cider.

In the process of fermentation, the microbes create vitamins and acids that may be beneficial to health. At the same time, the drink contains beneficial live-microbes.

Kombucha’s history stretches back over 2000 years to ancient China and it is also said to have been consumed in Russia and India. It has seen a comeback in the Western world in the past few years.

Microbial Strains in Kombucha

The microbial strains found in kombucha can vary in each batch, depending on the environment and the ingredients used. Typically it contains yeasts of the Saccharomyces species that seem to be beneficial to health (the yeast Saccharomyces boulardii is often used as a supplement to help prevent diarrhoea when travelling or to ‘outcrowd’ bad yeasts).

Brettanomyces is another yeast commonly found in kombucha.

Zygosaccharomyces kombuchaensis is a yeast only found in kombucha.

Other yeasts in kombucha can include Schizosaccharomyces, Torulaspora, Zygosaccharomyces and Pichia.

The yeasts produce alcohol, bubbles and acetic acid.

The two most commonly found bacterial strains are Acetobacter and Gluconacetobacter kombuchae, a strain unique to kombucha. Both produce acetic and gluconic acid. Other bacteria that may be contained in kombucha include: Gluconacetobacter xylinus, G. kombuchae, Acetobacter nitrogenifigens and Acetobacter intermedius.

Kombucha also sometimes (but not always) contains Lactobacillus and Pediococcus.

Acids in Kombucha

Universally, kombucha contains acetic and gluconic acid and fructose. The rest depends on the ingredients and brewing method used.

Acetic acid has anti-microbial properties and therefore kombucha may help remove unfriendly microbes in the digestive tract.

Gluconic acid is said to help with liver detoxification.

Nutrients in Kombucha

During fermentation, microbes in kombucha can create a number of metabolites, including nutrients that are beneficial for health.

These can include: fiber, organic and amino acids (especially lysine), vitamins, antioxidants,  enzymes and essential minerals (sodium, potassium, calcium, copper, iron, manganese and zinc) [1].

Benefits of Kombucha

Some claim that the benefits of kombucha are vast and miraculous, others say it may be dangerous.

Unfortunately there hasn’t been much research done on kombucha. Older research supports kombuchas benefits for the immune, endocrine, cardiovascular, gastro-intestinal and urogential systems [1].

Newer research supports the following benefits of kombucha [1]:

  • Antimicrobial activity
  • Improvement of oxidative stress
  • Improvement of cell toxicity from environmental pollutants
  • Fat-loss, cholesterol-lowering and antioxidant properties
  • Anti-ulcer properties
  • Protective effects on cell mutation from radiation
  • Liver-protective properties

Kombucha is a ‘symbiotic’, meaning it can provide beneficial bacteria plus food for those bacteria.

It also cheaper (if homemade) than probiotic supplements.

Anecdotally, kombucha may support the body’s recovery from different ailments such as digestive problems, allergies and migraines. It may also assist regulation of the intestinal pH, support the liver with detoxification and assist the flow of digestive juices.

In any case, it tastes delicious and is a great healthier substitute for sugary pop.

Potential Benefits of Kombucha for Bladder Health

I have found no studies about kombucha and bladder health, but a few potential benefits could be the following:

  • As kombucha is a liquid containing friendly live bacteria it may be a good option of getting ‘good’ bacteria into the bladder, potentially helping to ‘crowd out’ pathogens.
  • It may be a good way of providing food for beneficial bacteria already living in the bladder, potentially helping them grow.
  • It may provide nutrients that benefit the bladder wall.

Who Should Not Have Kombucha

  • In terms of bladder health, I would be careful using kombucha in cases of interstitial cystitis as the acidity of it may be too irritating.
  • It also should not be used for anyone with mast cell problems, as fermented products are high in histamine and could perpetuate problems.
  • Live bacteria should be used with care and never without guidance of a medical professional by anyone severely immuno-compromised or anyone with a high risk of sepsis.
  • People with yeast or mold issues may not tolerate kombucha well, at least not initially.
  • Anyone experiencing problems with even small amounts of alcohol or caffeine.

How To Get Started with Kombucha

If you’re new to kombucha you need to go slow and start with drinking small amounts at first. The introduction of beneficial microbes and nutrients can cause so called ‘die-off reactions’, depending on your health status.

The worse your health, the worse the reactions may be. These should ease off after a while though and you may start to see some benefits. If they don’t ease off after a while you might want to stop consuming kombucha.

As the microbial composition is not always the same, your kombucha may also contain strains that cause a problem for you. This can depend on the composition of your individual gut microbiome. So the trick is to go slow and watch for reactions.

There are two different ways to brew kombucha: the batch brewing method and the continuous brewing method.

For the batch brewing method you ferment the kombucha in a jar, consume it and then start a new batch.

For the continuous method the kombucha is fermented in a crock. Once it’s ready to consume you draw off some of the kombucha and then refill the same amount of fresh tea. The drink will be ready again in as little as a day. I prefer this method as it’s a lot less work.

To start your brew you need a SCOBY and starter liquid.

You also need to decide on your brewing method. It is recommended to use glass jars covered with cloth. It is not recommended to use any type of metal with the SCOBY. Don’t use a cheese cloth to cover the jar as it can let wild strains of bacteria and yeasts into the brew.

The brew needs warmth and good air flow to ferment properly. Throw away any moldy batches and start again.

When handling kombucha always make sure your hands and utensils are clean to avoid contamination.

The most basic way to make kombucha is by using black tea and white or brown cane sugar. However, there are other options depending on your taste.

The most commonly used sugar is white cane sugar. Other varieties of cane sugar can also be used. The sugar is food for the bacteria and will be consumed but the microbes before you consume the drink.

Other sweeteners like molasses, maple syrup, coconut sugar and honey may also be used but with very different results and tastes. Stay clear of xylitol and stevia as these will not feed and may even actively kill the microbes.

The following teas are good to use for brewing depending on your preference: all unflavored black teas apart from earl grey, all unflavored green teas, rooibos tea and coffee.

After you’ve brewed your basic kombucha you can give it flavors by second fermenting it (recipes to follow).


For the batch method:
  • 1 scoby
  • 200 ml of starter liquid from previous batch (you should receive some when ordering a scoby)
  • 160 grams of cane sugar
  • 3–4 tea bags or 3–4 tsp of loose tea
  • 2 litres of filtered water
For the continuous brewing method:
  • 1 scoby
  • 200 ml of starter liquid from previous batch
  • 320 grams of cane sugar
  • 12 tea bags or 12 tsp of loose tea
  • 4 litres of filtered water


For the batch method:
  1. In a pan, bring the water to a boil. Turn off the heat and add the tea and the sugar. Stir thoroughly and let steep for 30 mins. Let the tea cool (heat will destroy your culture).
  2. Pour the cool tea into the glass jar and add the starter liquid
  3. With clean hands put your scoby into the jar. It may sink or float.
  4. Cover the jar with a kitchen towel and secure with a rubber band
  5. Leave the jar in a warm, airy spot (not in a cupboard) and out of direct sunlight
  6. Leave for 5–15 days. You can start checking after 5 days. You want a sweet and sour and carbonated drink. The tea will get lighter in colour and a new scoby will form on top of the tea
  7. When your kombucha is ready you reserve a scoby and some tea in a bowl and strain the rest of the liquid into glass bottles ready to consume. You can now clean your jar and start your next batch.
For the continuous brewing method:
  1. In a pan, bring the water to a boil. Turn off the heat and add the tea and the sugar. Stir thoroughly and let steep for 30 mins. Let the tea cool (heat will destroy your culture).
  2. Pour the cool tea and the starter liquid into the crock and lift the scoby in
  3. Cover with a kitchen towel and secure with a rubber band
  4. Choose a warm but airy spot out of direct sunlight where you can keep your crock
  5. Leave to ferment 7–15 days. You can taste test after 7 days. You want the kombucha to be bubbly and sour but still sweet
  6. Once your kombucha is fermented to your liking you can draw off as much as you want to consume (but always leaving at least a pint)
  7. Then brew as much tea as you drew off, let cool and pour on top of the scoby
  8. The brew will be ready again after about a day (longer if you added a lot of new tea)
  9. Clean out the crock every 6 months, always reserving enough to start a new batch
  10. Occasionally take out extra scobys. You only need to keep one to keep the brew going.

Now I’d like to hear from you: What’s your experience with kombucha? Let me know in the comments!

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  1. Kozyrovska, N et al Kombucha microbiome as a probiotic: a view from the perspective of post-genomics and synthetic ecology Biopolymers and Cell. 2012. Vol. 28. N 2. P. 103–113

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