What is kombucha?
Kombucha is a legendary fermented beverage made from black tea and S.C.O.B.Y. (symbiotic culture of bacteria and yeast), commonly referred as kombucha mushroom, even if it has nothing to do with a fungus. There are several books and online resources as well about kombucha, where you can find more detailed informations. Here I just wanna give you some recipes to brew your kombucha at home, starting from the basic one, with black tea.
How to make kombucha, basic recipe
When you start to brew your kombucha, it’s better to begin with 2 litres. When your SCOBY has grown big enough and has reproduced itself, you can produce larger quantities of this wonderful fermented tea. I started to brew my own kombucha 4 years ago and I usually make 6 litres in a big glass jar.
What you need
One glass or porcelain jar
A thigh-weave dish towel
Ingredients for 2 litres
2 liters water
10 gr of organic loose black tea or 7 tea bags
150 gr refined white sugar
Some kombucha from a previous batch or the liquid you got with the SCOBY
How to do it
Bring the water to the boil, and infuse the tea in freshly boiled water, as you usually do to prepare your tea, for 20 minutes. Strain off the tea leaves or remove the tea bags, add the sugar before the tea has cooled and stir well to dissolve the sugar. Let the tea with sugar cool down and only when it’s lukewarm you can pour it into the vessel of your choice. Then add the SCOBY in the liquid. If it’s your first time, you cannot have kombucha from a previous batch. On all next batches, keep always some kombucha and add about one tenth (10%) of the quantity to the new batch together with the SCOBY. It will works as starter.
Cover the jar with the towel and secure it with a rubber band to ensure that fruit flies cannot get in.
Place your vessel in a warm and quiet place, don’t move it and protect it from direct sunlight to avoid temperature spikes.
The first fermentation should be ready in 7-10 days, depending on the temperature. The higher the temperature, the faster the fermentation.
The ideal temperature should be about 24°-26°. Light is not necessary.
When the tea has reached the right acidity (pH 2.7-3.2, but you can easily try it and see if you like it. After the first fermentation, kombucha should still have a bit of sweetness and a pleasant amount of acidity), you can pour the fermented tea into bottles and let the kombucha ferment for another week. I usually add some dry fruits like berries and a little piece of ginger to get a better carbonation and a very frizzy kombucha.
Sometimes, homemade kombucha can end up way too carbonated and the bottle can literally explode! This can happen when bottled kombucha is left too long in second ferment, under too warm of conditions, with too much fruit/ juice added, or some combination thereof. To avoid any problem and assess the carbonation level, the best way is to lightly burp the bottles. To do this, you want to only very slightly, hardly at all, lift the swing-top latch and lid. Burping does not mean fully opening the bottles. By doing so, all of the built up carbonation will easily be lost.
Before starting a new batch, clean the SCOBY under cold water and repeat the procedure as above. If you don’t want to start a new batch, store your SCOBY in a Tupperware with some kombucha and some sugar, and keep it in the fridge.
About sugar in kombucha
In his book “Kombucha. Healthy beverage and natural remedy from the Far East”, Günther W. Frank explains in a thorough way why white sugar is recommended for the preparation of kombucha.
“The kombucha culture is dependent on the supply of sugare, because it cannot produce it itself in sufficient quantities on its own. It has to be supplied with sugare in the nutrient solution”. Without sugar, SCOBY cannot work! “The use of sugar in the preparation of Kombucha worries many people and gives them a guilty conscience”. Frank explains again that “through the fermentation process, part of the sugar is used up. The residual sugar content of the completed beverage is determined by the degree of fermentation, which in turn is dependent on various factors. Because the beverage for reasons of taste is generally no left to ferment completely, a proportion of residual sugar remains – as it does with wine. If we suppose a residual sugar content of 30 g/l, this means 495 kJ = 118 kcal. A residual sugar content of 20 g/l works out at 330 kJ = 79 kcal. With a correspondingly longer fermentation period, which naturally must be paid for by concession to one’s taste-buds, an even lower calorific value can be reached. When considering calorific figures, one must also take into account the fact that these may be offset by the metabolic processes activated by the beverage”.