How to make kombucha: The ancient elixir
Posted on 24 January 2014
As we wrote in our post about sourdough bread, we are sour lovers – you can read about making sauerkraut and kefir on this blog, so we thought it was about time for kombucha too. We take this fizzy, acidic and slightly sweet drink to parties and introduce people to it wherever we go… and the thing that constantly surprises me is just how much people love it, often putting down their alcoholic drinks to switch to this probiotic goodness! You can imagine how chuffed that makes me.
The kombucha is made with a SCOBY, which is a Symbiotic Colony of Bacteria and Yeast that acts on sugar and tea to produce not only acetic and lactic acid but also small amounts of a potent detoxifying substance, glucuronic acid. Normally this organic acid is produced by the liver in sufficient quantities to neutralise toxins in the body – whether naturally produced toxins or poisons ingested in food and water. However, when liver function becomes overloaded, and when the body must deal with a superabundance of toxins from the environment additional glucuronic acid taken in the form of kombucha is a powerful aid to the body’s natural cleansing process, a boost to the immune system and a proven prophylactic against cancer and other degenerative diseases. Glucuronic acid kidnaps the phenols in the liver, which are then eliminated easily by the kidneys…
Kombucha is good for weight loss, allergies, building immune systems, fighting yeast infections, digestive issues, joint problems, reducing blood pressure, reducing kidney stones and more… of course, it’s not a panacea, it doesn’t cure everything! But what it does do is bring the body back into balance, alkalises it, so that it can heal itself naturally.
I’ve been giving kombucha workshops and love sharing all the great information about it but I feel there is just so much to know, so I suggest you go to this link for a great free e-book about making kombucha (you have to subscribe to their emails, but it’s useful and informative!): http://
The type of brewing vessel, water, tea and sugar that you choose is important. Make sure you use good quality glass (cheap Chinese glass often contains lead that can leach into your ferment and you shouldn’t use any metals, ceramics or plastics), uncontaminated, filtered water free of chlorine, organic tea and sugar. You can use black or green tea but not herbal teas as the oils in herbs will damage your SCOBY. The tea plant, camellia sinensis, contains several nutrients and compounds that feed the culture, including nitrogen, caffeine and theanine… so it’s a pretty important part of the process. Along with sugar, tea is the main fuel source for the SCOBY. We use plain brown (refined) sugar as the yeasts easily converts this into ethanol which the bacteria then converts into healthy acids. Without sugar, it won’t ferment and you don’t need to worry about consuming too much sugar as long as you ferment it long enough. In my workshops I go into detail about each of these but you can read about them from pages 17 to 31 here.
To make kombucha… We make around 10L of kombucha a week. We simply boil 10L water, add 14 black tea bags and 3 cups of sugar. Once the sugar has dissolved and the tea mixture has cooled we pour it into our brewing vessels, add some of the fermented kombucha tea from the previous batch and add a SCOBY (check the ratios for the amount you want to make on page 53, here). We then secure a tightly woven cloth on top of the vessel with a rubber band and leave it to ferment at room temperature, on our kitchen bench, away from direct sunlight (UV will kill the yeasts) for 7 days. This part of the fermentation process is aerobic, meaning the SCOBY needs oxygen. As the kombucha tea ferments the SCOBY consumes the tea and sugar, producing vitamins, minerals, enzymes, carbon dioxide and more. Ideally you want the temperature to be between 21 and 26.5 degrees Celcius. If it is too cool, the fermentation process will slow. If it is too hot, it will ferment faster. You can ferment it for up to 3-5 weeks if you like but then the taste is much more like vinegar. The ideal pH, if you are inclined to test it, for consumption will be between 2.6 and 4.0. Over brewing starts between 4 and 6 weeks and you need to be careful you aren’t starving your SCOBY. At the end of the week our mother SCOBY has produced a baby SCOBY, the tea is no longer sweet and it’s ready to drink or second ferment.
Second fermenting with fruit produces a refreshing carbonated drink. A friend’s 4 year old doesn’t seem to realise it’s healthy for you, often asking for the ‘gassy’ drink (I think he thinks it’s a soft drink!) :). To second ferment, we remove the SCOBY, bottle up our kombucha into grolsch-style bottles, add fruit, spices or herbs for flavouring and seal them to make them anaerobic (without oxygen). Filling the bottles (leaving only 1-2cm of space), then sealing them reduces the amount of oxygen in the bottles meaning that the carbon dioxide produced by the fermentation is dissolved into the kombucha tea, making it delightfully bubbly! We then leave our sealed and flavoured kombucha at room temperature for a couple of days before refrigerating and then enjoying as we like. Below are our bottles in our fridge… we go down to the local German bar to ask for their empty ones but you can get creative with whatever you can get your hands on! In the past we’ve used old wine bottles, pushing the corks back in… as well as small beer bottles, refitting the lids.
We love getting creative with flavouring ideas:
The main problem people seem to encounter with kombucha is the development of mould. We’ve never had this problem and it should be unlikely given the acidic nature of it, but if it happens to you perhaps you forgot to add an ingredient or mixed up the ratios which could alter the pH. The other thing to be aware of are contaminants like soap, food residue, mould spores in tea, poor hygiene, transient yeasts/bacteria from a nearby bin or other ferment… If you develop mould do not try to save it. Start again with a new SCOBY. We use a SCOBY hotel to keep all our extras that are made each week and this is where we’d get our ‘new’ SCOBY from if the ones we are using become contaminated. A SCOBY hotel is simply a glass vessel with a tea/sugar mixture in it that we put our SCOBYs in. We secure it with a tightly woven cloth and a rubber band and leave it in a dark cupboard, feeding it occasionally with more tea/sugar to ensure they don’t starve (at least every 6 weeks). Other problems could be that pests like ants and fruit flies are attracted to your fermentation. To ensure fruit flies can’t get inside to lay their eggs make sure the cloth on top of your vessel is very securely attached and that the weave of the cloth is tight. If your SCOBY turns black it is dead, so throw it out and start again with one from your hotel. If your fermentation is still sweet then it’s not fermenting so the first thing you should check is that the environment it’s in isn’t too cool. Here is a quick list of things you shouldn’t do..
- use chlorine as it kills the bacteria, however do sanitise your kitchen, utensils and hands with hot water and vinegar
- use soap
- use plastic, crystal or ceramic
- use tap water – filtered water is recommended
- use stevia, raw honey or herbal teas
- use a cheesecloth cover as its weave is too loose, allowing fruit flies and stray yeasts and bacterias in
- store in direct sunlight, in closed cupboards or in a cool location – you want a warm location with good air flow
- disturb the vessel during fermentation
- pull new starter liquid from the bottom of the batch
- try to salvage a mouldy batch of kombucha tea
- put your SCOBY in the fridge – if you are going away, simply feed it with more tea/sugar and it’ll be fine for 6 weeks
We have also been enjoying our kombucha in other recipes like those below:
Enjoy your kombucha journey!!