Making kombucha isn't just about following a recipe. It's about witnessing a living process with many variables, dependent on both nature and your connection to the culture. One of the most frequent questions is: "When should I harvest my kombucha?" The answer seems simple, but within all simplicity lies complexity. And that's what we're going to explain:

There is no ideal fermentation time, but rather the time necessary for the transformation.

In this article we will explore two fundamental aspects. First, the fermentation time and how to recognize the harvest point. Then, what really happens inside the jar, what we call the magic, or the science, of kombucha, and what accelerates the fermentation process.

Fermentation time: when to harvest your kombucha

The SCOBY does the work, but it's important to be connected to it. Whether you're just starting out or have been fermenting for a while, this guide will help you better understand when your kombucha is ready to be harvested and enjoyed.

Fermentation is not an exact science, with several variables influencing the process. The fermentation time and the transformation of sweet tea into kombucha depend on various factors, such as:

• Ambient temperature
• Strength and acidity of starter tea.
• Number of SCOBYs used
• Size and shape of the fermenter
• Oxygenation level
• Quality of ingredients
• Personal preference for a more acidic or sweeter flavor.

Of all the factors, temperature is the most decisive. When the environment is cold, below 18°C, bacteria and yeasts work very slowly, and if you don't have a strong culture, they risk not fermenting. Furthermore, low temperatures can favor contamination, since fermentation activity is weaker.

At warmer temperatures, between 22 and 27 ºC, fermentation occurs at a rate considered ideal.

Important : Another crucial point is the balance between the starter and the SCOBY. If you use too much starter, or if it's too acidic, your kombucha may begin fermentation with a very low pH. This means that when you taste it after a few days, you'll experience a strong acidity that doesn't always result from the natural process, but rather from the initial excess of acidity.

The same thing happens when you add too many SCOBYs: besides being rich in microorganisms, they are also a very acidic substance and end up intensifying the vinegary taste right away.

And how do you determine the harvest point?

The answer lies in the practice of sensory analysis. It uses taste, smell, and sight. The moment you notice that the transformation of sugar into acids is clear, you can call that liquid kombucha. The exact point depends on your taste. The longer you let it sit, the more acidic and less sweet the result will be.

In professional production, where almost all variables are controlled, the harvest point is determined by measurements of pH, acidity, and sugar levels. In home production, however, there's no need for such technical expertise. The simplest and most efficient approach is to trust your senses and personal taste.

Over time you will notice very clear visual signs. In each fermentation cycle a new SCOBY is formed on the surface of the flask. It is also normal to see strands of yeast, sediment deposits at the bottom, and small CO₂ bubbles appearing in the beverage. The mother SCOBY may darken, float, adhere to the new film, or sink. All of this is normal. There is no fixed rule; the culture positions itself as it feels best.

What happens during fermentation: the magic and science of kombucha

In the first fermentation, the SCOBY transforms the sweet tea into a living liquid through the combined action of yeasts and bacteria. The sugar is consumed, first converted into alcohol and then into organic compounds that give kombucha its flavor, acidity, and character.

If you want natural gas, this only happens in the second fermentation (anaerobic, see this article). In this stage, which takes place in the sealed bottle, the work is mainly done by the yeasts, which produce alcohol and carbon dioxide, creating the natural effervescence of the beverage.

The result is simple and extraordinary: what was just sweetened tea is transformed into kombucha, a probiotic drink that is refreshing and full of personality.

Conclusion

Fermentation time should not be seen as a fixed rule, but rather as a dance between the culture, the environment, and your personal taste. The more you practice, the easier it will be to recognize the right point and understand the transformation that takes place inside the jar.

In the first phase of the process, yeasts transform sugar into alcohol and CO₂. In the second phase, bacteria convert this alcohol into organic acids. The result is a rich and unique probiotic beverage.

The next question is How do I collect my Kombucha? See this article.