Dr. Katie Takacs B.S., D.C.
It is very common now to see glass bottles front and center in the grocery store, filled with carbonated, ginger flavored kombucha. What the heck is kombucha? Why are so many people consuming it?
What is Kombucha?
Kombucha is a fermented drink consisting of tea and sugar that’s used as a probiotic food. During the fermentation process of creating kombucha, a large number of healthy bacteria grow. Yeasts use the sugar in the tea to produce ethanol. This is then consumed by bacteria to produce acetic acid (vinegar). During the process of fermentation, a SCOBY develops. SCOBY is an acronym for ‘Symbiotic culture of bacteria and yeast’.
There are several compounds and strains of bacteria and yeast produced during this fermentation process. Saccharomyccesis a beneficial yeast that is produced during fermentation. This yeast can help to populate the gut with beneficial yeast and will help to crowd out potentially harmful yeast such as Candida albicans.
Acetobacteris an aerobic bacterium that produces acetic acid and gluconic acid. Gluconic acid is considered to be the main therapeutic agent in Kombucha, as it functions in the liver as a detoxification agent. Acetic acid is also produced, and it is considered to be the major antimicrobial agent present, by inhibiting a range of gram + and gram – microorganisms (2).
Benefits of Kombucha:
Kombucha may help support the liver due to its strong antioxidant activity. One study found that after treatment with Kombucha in acetaminophen induced liver damage, liver markers dropped. Before treatment, there were increased levels of aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Following treatment by Kombucha, these levels all dropped significantly (6).
The live culture in this drink provides many beneficial probiotics. Probiotics can provide your gut with healthy bacteria. These can help to improve digestion, inflammation, and decrease gas and bloating. When made with green tea, there are many additional benefits provided. Green tea contains many bioactive compounds, like polyphenols, which act as very strong antioxidants within the body (7). Drinking green tea can increase the number of calories you burn, decrease belly fat, improve cholesterol levels, and can also help with blood sugar control (8).
Reduction of Candida:
Since this drink contains both anti-microbial and beneficial yeasts, it works well at reducing candidaovergrowth. Overgrowth of this potentially pathogenic yeast can lead to (3):
- Brain fog
- Vaginal Infections
- Difficulty concentrating
- Increased inflammation
- Decreased immune response
- May worsen mental illness (schizophrenia and/or bipolar disorder) (4)
The low pH and presence of anti-microbial metabolites present reduce the competition of other bacteria, yeasts, and fungi. This may be effective at reducing H. pylori known for causing peptic ulcers, or E. coliknown for causing diarrhea (2). This antimicrobial activity is attributed to the low pH value of this drink.
Gut Function and Mental Health:
There is a very strong connection between the gut and the brain. Something referred to as the gut-brain-axis. Recent evidence has linked dysbiosis and inflammation of the gut to causing several mental illnesses including anxiety and depression. It has been found that probiotics have the ability to restore normal balance within the gut, therefor they have a potential role in the treatment of anxiety and depression disorders (9).
In a study published in Psychosomatic Medicinefecal samples were supplied by women. MRIs were taken of their brains as they viewed different imagery that evoked different emotional responses (5). It was found that one group of women had a high amount of Bacteroidsand the other had high levels of Prevotella. It was found that women who had the Bacteroidsshowed greater thickness in the gray matter in the frontal lobe- areas of the brain associated with complex processing of information. The women who had higher levels of Prevotellashowed more connections between emotional, attentional, and sensory brain regions. These women also rated higher levels of negativity such as anxiety, distress, and irritability while looking at negative imagery when compared to the other group. This study suggests that there is a major connection between emotions and gut function (5).
Kombucha is considered generally safe, however there are some concerns that people may have.
- Caffeine- generally the tea used to brew kombucha is caffeinated. It is estimated that the caffeine content is reduced by 25% over a two-week brewing period.
- Sugar- Kombucha starts as a very sweet tea. However, as it ferments, the tea becomes more tart and less sweet (as the culture feeds off of the sugar).
- Alcohol- there is still alcohol present as a byproduct of the fermentation process. It is typically low but should still be considered present within the kombucha.
- Children- This drink is considered safe for children; however, you should always consult with your doctor before starting any new dietary regimen.
How to Make Kombucha:
Alright, alright, so now that you know the many benefits of Kombucha, I’m sure you’re interested in how to make it on your own.
- 1 bottle of GT’s unflavored Organic Kombucha
- 6 cups of water
- 1 cup of sugar
- 6 tea bags (black, white, or green) – no flavored
- Large glass jar
- Cheesecloth or coffee filter
- Rubber band
Some key rules:
- Make sure to keep this process very clean.
- Rinse everything with vinegar and use paper towels to dry.
- Antibacterial soaps can affect growth, and dish towels can hold a lot of bacteria.
- Brew your tea
- Bring water to boil, add sugar and tea bags.
- After this, cover pot and allow tea to cool to room temp
- Let bottle of store-bought kombucha get to room temp as well.
- Add Kombucha
- Once the tea has cooled, add sweet tea mixture and entire bottle of kombucha to glass jar.
- Cover with coffee filter and secure with rubber band.
- Set the jar in a spot that’s not in direct sunlight, but also in a place with good air flow (i.e. not a cupboard)
- Allow kombucha to sit for 3-5 weeks for the FIRST FERMENT
- The kombucha will have a sour-vinegar flavor when it has fermented enough. If it still tastes sweet, it needs to ferment longer.
- Second Fermentation
- Once the kombucha is ‘done’ you can ferment it a second time to give it flavor.
- During this process, remove the SCOBYs and save 1 cup of the kombucha- set aside.
- To start your new batch: Rinse jar and repeat steps 1 & 2.
- This time, you will use the kombucha you set aside in place of the bottle that you used the first time.
- The fermentation this time won’t take as long, since you have already grown a SCOBY.
- *Fermentation times may vary based on temperature, humidity/etc.
- Second fermentation (How to flavor)
- Transfer fermented kombucha into glass bottles/jars
- Add your choice of fruit and herbs and let sit on counter covered for about 2 days.
- Be sure to “burp” the bottle 1-2x/day. Sometimes carbonation will build up- you don’t want your bottles exploding.
- You can move bottles to fridge. Enjoy!
- As the SCOBY develops, you will begin to see little bubbles on top of the tea. These will eventually turn into a thin filter- this is your SCOBY!
- Keeping a clean workspace can help to prevent this from happening. However, if you see abnormal colors, it is time to THROW OUT the batch and start over.
- Do not try to salvage any part of the batch, ifthere is abnormal growth, the entire batch must be thrown away.
- This may appear blue, black, green or white/tan and dry and/or fuzzy.
- It will typically be located on top of the culture (not usually under it).
- It will appear like mold you have seen before- similar to mold on too old food.
- You may also notice a ‘stringy’ layer that forms to your SCOBY. This is normal as long as it is the same color as your SCOBY- this is yeast growth.
- Watawana, Mindani I.et al. “Health, Wellness, and Safety Aspects of the Consumption of Kombucha.” Journal of Chemistry, vol. 2015.
- Teoh, Ai l. Et al. “Yeast ecology of Kombucha fermentation.” International Journal of Food Microbiology, vol. 95, 2004, pp. 119-26.
- Kumamoto CA. Inflammation and gastrointestinal CandidaCurrent opinion in microbiology. 2011;14(4):386-391. doi:10.1016/j.mib.2011.07.015.
- Emily G Severance, Kristin L Gressitt, Catherine R Stallings, Emily Katsafanas, Lucy A Schweinfurth, Christina L Savage, Maria B Adamos, Kevin M Sweeney, Andrea E Origoni, Sunil Khushalani, F Markus Leweke, Faith B Dickerson, Robert H Yolken. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder. npj Schizophrenia, 2016; 2: 16018 DOI: 10.1038/npjschz.2016.18
- Tillisch K. Research suggests association between gut bacteria and emotion. Psychosomatic Medicine. 2017;79(8):905-913.
- Da MA, Kabiri N, Rafieian-K M, Setorki M, Doudi M. Protective Effect of Kombucha Tea on Liver Damage Induced by Thioacetamide in Rats. Journal of Biological Sciences. 2014;14(5):343-348. doi:10.3923/jbs.2014.343.348.
- Serafini M, Ghiselli A, Ferro-Luzzi A. In vivo antioxidant effect of green and black tea in man. European
Journal of Nutrition . 1996;50(1):28-32.
- 8 Evidence-Based Health Benefits of Kombucha Tea. Healthline. https://www.healthline.com/nutrition/8-benefits-of-kombucha-tea#section2. Accessed August 28, 2018.
- Gut Brain Axis: The Gut & the Brain – How Gut Bacteria Affects Mental Health. OptiBac Probiotics. https://www.optibacprobiotics.co.uk/blog/2018/03/gut-brain-axis. Published March 1, 2018. Accessed August 28, 2018.
- All photos used from Google Images.