The popularity of kombucha has exploded in the last several years. This functional drink didn’t even enter the American market until 1995, yet by 2015 it was a $0.6 billion industry, and its growth is expected reach $1.8 billion by 2020. Despite its status as a raging trend, what I love about kombucha is that it is nothing new – it has been around for centuries, perhaps even as early as 221 BC in China, where it was known as the “tea of immortality.” Kombucha is historically known as a healing beverage, and it continues in that tradition today.
Is Kombucha a probiotic drink? Is it some kind of panacea? Let’s get the story straight.
Kombucha is a fermented tea made by combining tea, water and sugar with an existing SCOBY, which stands for “symbiotic colony of bacteria and yeast,” plus a bit of existing kombucha tea to get the process going. During fermentation, bacteria and yeast consume sugars and nutrients and in turn create beneficial byproducts. The actual components in the final product have been the subject of a lot of debate and, as yet, limited research.
Is kombucha a probiotic drink? The mention of bacteria causes many to assume that kombucha is a probiotic beverage, but not all bacteria qualify as “probiotic.” At the most basic level, to qualify as a probiotic, a microbe must possess qualities – and be present in a quantity – known to provide health benefits when consumed (follow the link to see other requirements). So, the question is, are probiotic strains of bacteria found in kombucha in quantities that will have a positive impact on one’s health? The most recent and reliable study of kombucha was released in 2013 by Alan J. Marsh et. al. – the researchers examined five different kombucha samples from around the world using advanced techniques not implemented in previous studies. I acquired the full length article of this study to get the clearest picture I could. The study reported the presence of several bacteria genera, the primary three being Acetobacter, Gluconacetobacter and Lactobacillus; the relative amounts varied depending on the sample . Unfortunately, the researchers did not identify the specific species and subspecies of these genera, which is necessary to determine their probiotic value. The one exception was that the most common Lactobacillus strain appeared to be Lactobacillus kefianofaciens, which is known to confer a number of health benefits. In addition to the presence of the beneficial Lactobacillus bacteria found in the kombucha samples, I came across enough research on the bacteria Acetobacter to have me convinced that, in one way or another, kombucha does likely contain “probiotics” (again, the exact strain must be identified to be sure, which this study did not accomplish definitively).
This however, only answers half the question. The other half is, are these probiotics present in high enough quantities to have a positive impact? The study did not get specific about the bacteria count, but stated “it is generally thought” that after 10 days of fermentation, there are somewhere between 5,000 and 500,000 CFU (colony forming units) of bacteria per milliliter of kombucha. (The presence of Lactobacillus strains in this study accounted from 0%-30% of the bacteria found; Acetobacter from 0%-2%; and Gluconacetobacter from 58%-99.8%). This may sound like a lot, but compare it to other known probiotic-rich foods: 48 million-950 million CFU/ml in yogurt, a reported 10 billion CFU/ml found in milk kefir and 48.2 billion CFU found in a serving of a popular probiotic supplement. Daily recommended dosages range from 10-20 billion CFU daily for an adult. I’m not a certified nutritionist (and my research has to stop somewhere!), but it appears to me that the potential quantity of probiotics in kombucha really falls short. I am well aware that in addition to quantity, probiotic diversity is also very important, but that information is outside of the scope of current research. I should note that many manufacturers add probiotics to their kombucha. Just know that if you brew at home, your kombucha is not a good source of probiotics.
So what are the known benefits of kombucha? Does kombucha cure ailments? The beneficial byproducts of kombucha fermentation include organic acids (primarily acetic acid, glucuronic acid and gluconic acid), B vitamins, vitamin C, amino acids, and enzymes. The most notable of these is the glucuronic acid, which is a powerful detoxifier. Glucoronic acid is produced by the body to flush toxins out of the system, but many factors can either over-load the liver or reduce its ability to work properly (alcohol, medications, environmental toxins, etc.), which makes the glucuronic acid in kombucha valuable.
The unique combination of acids, microbes, vitamins and enzymes in kombucha tea, plus its long anecdotal history of healing, has inspired a fair amount of research regarding its antimicrobial, antioxidant, hepatoprotective, and anticancer properties. However, as this review of kombucha research states, “most of the benefits were studied in experimental models only and there is a lack of scientific evidence based on human models.” I believe that the prudent conclusion on the matter is that kombucha aids the body as a whole, but is not neccessarily a “cure” for these diseases or conditions. This is not to devalue the potential benefit of kombucha – research aside, the hundreds and thousands of years of anecdotal evidence alone is very convincing to me. So, despite the misinformation that’s out there, kombuchua is definitely a beverage that I include in my family’s diet to benefit our health, although it may be a few more years before we find out exactly what kombucha is doing for us and how!
If the chemical makeup of kombucha is overwhelming, don’t worry – the process of brewing your own is simple. If you’ve made it this far in the post, you’ll be able to brew it no problem 😉 My first introduction to kombucha was a few years ago from a neighbor who has been brewing it since his “hippie years.” I have been using his recipe ever since with great success. Below is the basic recipe I use plus the steps to follow for fermentation and flavoring. Enjoy!
You Will Need:
Water – Filtered or spring water is best for the health of the SCOBY.
Tea – Not all tea works well for kombucha. I use either English Breakfast, Rooibos or Jasmine tea. Loose leaf or tea bags both work; organic is preferred.
Sugar – Processed “white” sugar should be used, as it is the easiest for the bacteria and yeast to consume. Organic is preferred.
A SCOBY – you can order these online, but even better is to get one from a friend who brews kombucha.
1 cup kombucha tea – you will likely be able to get some tea along with your SCOBY. If you can’t get existing kombucha tea, it’s ok to use a cup of vinegar instead.
4 quart or larger stock pot
Mesh tea infuser if using loose leaf tea
One gallon or larger glass container with a wide opening
Paper towels and a large rubber band to secure the paper towels over the glass container
Tightly sealing bottles, such as old wine bottles with screw-on caps, flip-top glass bottles or mason jars
1. Brew Sweet Tea
In a large pot, bring one quart (4 cups) of water to a boil on the stove. Remove from heat and, using a mesh tea infuser, add 2 tablespoons of loose leaf tea. If using tea bags, use 6 tea bags. Cover and let steep 10 minutes. Add 1 cup of sugar and stir to dissolve. Add an additional two quarts (8 cups) of cool water to the tea.
2. Combine Sweet Tea with SCOBY and Kombucha Starter
After adding the two quarts of cool water, the sweet tea should be only slightly warm. If the tea is too hot, it will kill the bacteria and yeast in the kombucha. Place your SCOBY, one cup existing kombucha or vinegar and brewed sweet tea together in your large glass container. Cover the container with a double layer of paper towels and secure with a rubber band. This will allow the kombucha to breath while keeping bugs and dust out.
3. First Ferment
Allow your kombucha to sit at room temperature for at least one week, and up to a month, generally speaking. The longer the kombucha brews, the lower the sugar content and the stronger the flavor. I have come to prefer my kombucha quite strong. Start sampling your kombucha after a week to determine your preference. Conditions should be between 70-80 degrees Fahrenheit. Warmer or cooler conditions can cause problems. Also avoid placing the container in direct sunlight. Signs that your kombucha fermentation is going well include an increasing vinegar odor, visible bubbles rising to the surface, and the formation of a new SCOBY on the surface of the tea. At first it will be nearly translucent, and then it will develop into a whitish, opaque, rubbery mat (see photo below – a new SCOBY forms on the surface, the previous SCOBY has fallen below). Brown strands, goop and other slimy things floating around are normal – these are strands of yeast. Anything green or that looks like mold forming on the SCOBY is not. A rotten or funky smell also is not normal. You can drink the kombucha at this point, or continue with a second ferment.
4. Second Ferment (Optional)
The second ferment is where you can get creative with flavors and build up some extra combination. Fruits, juices, herbs, spices and extracts can be added for all sorts of flavor combinations. The general rule for fruits and juices is about 10-30% fruit or juice to kombucha tea (see photo below). First place your fruit/juice/etc. into one of your tightly sealing jars, and then add kombucha from your first ferment, leaving an inch or two of headspace. Tightly seal the lid and allow to ferment for an addition 2-7 days or so. Be careful opening the containers, as depending on the conditions, a great deal of carbonation can build up. I’ve had some batches turn out completely flat, and some spray my ceiling with kombucha. The tightness of the seal and how much sugar is in the second ferment at the time you cap it are big factors in creating carbonation. (Thus, if you are not getting enough carbonation, try cutting your first ferment short and/or increasing the fruit or juice added (for a natural sugar source); you can also try increasing the duration of your second ferment.) In the first photo below, you can see the proportions I used: the jug on the left is just frozen blueberries, and the bottle on the right is a mixture of limes and mint, for a resulting flavor reminiscent of a mojito 🙂 The second photo is after I added the tea (the smaller bottles are flavored with strawberries and fresh ginger). Once your second ferment is to your liking, refridgerate your tea to stop the fermentation process. Chilling can also have the effect of “setting” the carbonation.
The Ongoing Process
Whenever you remove kombucha from your main brewing container, just be sure to reserve at least 1 cup for your next batch. It is ok if there is more. The more kombucha present when you add fresh sweet tea, the faster the fermentation for your next batch will progress (for example, if you add half a gallon of sweet tea to half a gallon of fermented kombucha with the SCOBY, it will probably be ready to go in a couple days). Watch for signs of healthy activity and test flavor to determine “doneness.” Whenever disturbed, such as when you remove tea, your SCOBY will sink, and a new one will start to form on the surface. It’s ok to let these build up. Whenever they start taking up too much space, remove the older ones and leave a healthy SCOBY for future brews. Yes, the SCOBY is edible – in my opinion the texture is undesirable, but my kids will gobble it up if I let them. You can also add a slice to a smoothie for a boost. According to the Alan J. Marsh study I mentioned above, the SCOBY may contain higher concentrations or different strains of bacteria than the tea itself.
Please give this a try and share your questions and successes! And if you live in my area, feel free to ask for a starter SCOBY – I have plenty!