Fermentation with SCOBY

Symbiotic Culture Of Bacteria and Yeast”


A Scoby is a thick, rubbery and cloudy mass; it is a substance that is formed after the completion of a unique fermentation process of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast used in the production of various types of sour food and drink.

It is easy to find a Scoby nowadays, but where precisely did the first Scoby come from? Its exact origin is mysterious, but it probably came from an ancient Eastern culture where fermented foods were constantly popular. Numerous stories have been passed along over time and here are the 3 most common origins of where in the world the primary Scoby came from:

  • The most common legend comes from China and dates back to 221-206 BC where it is believed that the emperor Qin She Huang extended his lifetime by drinking the “Tea of Immortality” created for him by an alchemist. There is some speculation among scholars as to whether this was truly kombucha or reishi mushroom tea.
  • Russian folklore says a monk with healing powers was beckoned to help a dying emperor. The monk promised to save the emperor with an ant that he drops into the emperors’ tea and instructs him to wait until the jellyfish forms to drink it. The tea transformed into a healing potion that saved the emperor.
  • According to a legend out of Tibet, a monk fell asleep and a bacteria-carrying insect landed in his fresh pot of tea. The teapot was forgotten, and a culture was able to form. When the monk discovered the incredible properties of this tea, he shared it with friends.

picture by Federico Pasian


Scobies have evolved to become what they are today.  For this reason, they cannot be created spontaneously in fast times.

With the Scoby fermentation, you can produce different sour/tangy drinks. For example Kombucha, milk Kefir, and Tibicos (water kefir).

In this case, we will talk about how to make a Scoby for a Kombucha. As you know you cannot make your own Kombucha’s Scoby starting from zero. The best things to do is to buy a mature Scoby or to buy an unpasteurized Kombucha and you will find some links below where you can buy a Scoby:

Italian link here

Italian link here

Italian link here

In the fermentation of Kombucha the SCOBY separates yeasts that produce alcohol from those that produce acetic acid; once created the mother can be used as a starter for the next fermentation and also after every process the SCOBY will create a new SCOBY and so on.

Adding a small piece of SCOBY in a solution with fermentable raw material, such as an infusion or juice, will quickly generate a new fermented; The SCOBY created at room temperature must be kept at a low temperature not in contact with direct light and heat sources, going to feed it weekly with another infusion or with a new tea.

picture by Federico Pasian



Kombucha is a fermented drink that is a relative of beer, wine, water kefir, kvass, and tepache – but also of many other fermented foods such as yogurt, kefir, kimchi, sauerkraut, and tempeh – rich in beneficial properties for our body. Kombucha is an important food rich in “friendly” bacteria, antioxidants, polyphenols, and B vitamins. It is also an excellent ally in the purification of liver and blood and ideal for strengthening the immune system.

It is a “live drink” based on tea, slightly sparkling, with few sugars and rich in beneficial properties that are obtained from the fermentation of sweetened tea through SCOBY, a culture of bacteria and yeasts our friends. It is counted among the allied foods of our body as a functional drink thanks to its many benefits.

How to make it? If you want to try preparing your kombucha we recommend following these steps:

  1. Prepare the infused tea (usually, green or black tea are recommended);
  2. Add 5-10% of sugar;
  3. Wait for the tea to cool down below 40 degrees,
  4. Pour the tea into a jar;
  5. Add the Scoby (plus 15% of ripe Kombucha) or the 15% of unpasteurized kombucha;
  6. Cover the top of the jar with a cloth and secure it with a rubber band;
  7. Allow to ferment at temperatures always below 40 ° C, but never under 20 ° C, and away from sources of heat and direct light for about 7-14 days;
  8. Pour it into a bottle (‎CO2 will form);
  9. Keep the SCOBY and 15% of ripe Kombucha; 
  10. Start over from point 1.

picture by Federico Pasian

Recipe for 1 liter:

900g of sweetened tea (45gr of sugar + 855gr of tea)

Add 100g of ripe Kombucha

Add the Scoby (only the top layers)

The kombucha liquid can be used to create carbonated drinks, in this case, it is preferable not to excessively lengthen the fermentation times (usually around the 10th day). For spontaneous carbonation 5 days should be enough to make the yeasts produce enough CO2. The mother can also be used as an ingredient or perhaps as a decoration: if we put the Scoby vacuum-packed with sugar you can get a candied result, maybe even dried for a few hours to give it a crunchy texture.

To obtain an excellent gassing, it is necessary to privilege yeasts. You can use different methods:

  • Anticipate bottling on standard timescales,
  • Increase the percentage of sugar with equal timeframes,
  • Aromatizing in a bottle,
  • Fruit and fruit juices strengthen the gassing process.

In a bottle pour 20% more mature Scoby than the sweetened tea into a bottle to fill it. Put the aromas directly inside the bottle to increase the gassing and to aromatize.

To control the ‎CO2 inside the bottle, we advise you not to use crown caps, (the bottle could explode). 

picture by Federico Pasian


We could also try to make a Kombucha with other types of infusion rather than black or green tea but remember that there is no specific Scoby for various types of tea. To modify the infusion, you could use different types of tea or spices, you could also change the type of sugar (honey, maple syrup, muscovado, etc…). Do not aromatize the main brew but start with small batches. Adding the 20% of ripe kombucha on your new infusion batch will help to start the fermentation.

If you produce and drink a lot of kombucha it will be easier and faster using the Continuous Brew method.

This technique is recommended if you consume 6-7 liters a week of kombucha. How does it work?

First, you need a big jar with a tap. Then you start to pour the sweetened tea and add the Scoby. Once the Kombucha is ready you can serve it from the jar’s tap. When the kombucha level inside the jar is decreasing, pour some more sweetened tea for restarting the procedure again. Do this procedure whenever you feel it is necessary. It is important to keep the continuous brew at lower temperatures (22°- 25°C). Occasionally, you must to do the Scoby maintenance. This means removing the older bottom layers.

picture by Federico Pasian

Temperature plays an important role in brewing kombucha. Here’s some temperatures information to ensure your homemade kombucha is brewing at its peak temperature;

43°C = Death beginning

38°- 42°C = Non-Active bacteria

30°- 38°C = Yeast dominates

26°- 29°C = Ideal to start the scoby

22°- 25°C = Ideal for the continue brew

18°- 21°C = Yeast dominates

10°- 18°C = Kombucha hotel

Where and how you can keep your numerous Scoby safe when you are not using them?

  1. Place all the Scoby in a clean container,
  2. Add Kombucha to cover the Scobys,
  3. Add sweetened tea (10%) every 1-2 months,
  4. Close with a lid or let a new Scoby act as a lid.

picture by Federico Pasian


  1. Fruit skins (fruit and sugar blended with Scoby and dried),
  2. Nata (candied Scoby),
  3. Thickener,
  4. A vegetable alternative for vegan “charcuterie”.

pictures by Federico Pasian


When creating a new batch, add ripe kombucha and sweetened tea without exceeding PH 4,2 (avoid mildew formation), or at least PH 5 (botulinum formation). Always monitoring the temperature and do not go below the PH 2.5.

Do not serve more than 150-200 ml if not a regular consumer.

written by Pasquale Bergamo and Diego Guazzarotti