Kombucha Fermentation and Water Quality: What Kind of Water Does a Scoby Like Best?

Leogant Founder Thomas Hartwig reveals all his expert tips on vitalized water in an exciting interview!

High-quality water is essential for our unpasteurized kombucha. Just like our bodies, a scoby quickly recognizes which water benefits it most. Water for fermentation should always be filtered and free of harmful residues. In our exciting interview with Leogant Founder Thomas Hartwig, you'll get many important insights into water and water filtration. We also give you useful tips on how to filter and treat your water at home for kombucha fermentation.

The journey to Leogant's founding by the Berlin water guru

How did you come up with the idea to found Leogant? Please introduce yourself briefly!

I founded Leogant about 12 years ago. The founding was much more than a simple business case. It was more a life's mission, always with a clear focus on a conscious business with meaning. From the beginning, there was always a clear purpose, which was to give people a good feeling with good water. The business model was rather secondary. I myself am a trained restaurateur and later studied the Asian martial art of Kung Fu in China. I have always had an affinity for high-quality food and a good body feeling. Back in Berlin, I continued to focus a lot on nutrition and sports and ate a vegan diet. With 6 hours of exercise a day, I quickly noticed how much more efficient my body was with high-quality spring water from the organic market. This had such a great impact on my performance and regeneration that the topic of water never let me go. In general, I slowly began to perceive my body more holistically. 

Actually, it's obvious, because our body and our earth consist largely of water. My body changed with high-quality water not only during physical activities and high-performance sports, but I also noticed a positive influence on concentration and body odor. Water is also very interesting on a scientific level. No substance has so many properties, anomalies that science cannot explain. With the founding of Leogant and our water filter systems, I have developed a sustainable and holistic solution to address people's individual needs and want to bring the importance of water for our organism more into focus. All of this with a sustainable business without compromise.

How does the LEOGANT filter work?

I used to pack the first boxes with water filters myself in my 20 square meter office. I collected cardboard boxes from everywhere to work as sustainably as possible. This sustainability, which was not as in vogue then as it is now, is still reflected in our filter systems today. All components of the water filters are existing products. From the very beginning, I meticulously examine what the market already offers, take existing systems apart, see how I can improve them, and reassemble them as newly combined water filters.

The 2-Phase Filter System

The important underlying approach is a very consistent natural approach, or rather, a natural water refinement. Our 2-phase system filters and – what is special – it vitalizes the water. This means that in the first phase, with the help of activated carbon cartridges, residues of hormones, medications, pesticides, microplastics, parasites, lead, copper, chlorine, and many other chemical and organic residues are removed. In the second phase of water refinement, vitalization takes place, which turns tap water into living water of spring quality.

What happens to the limescale in the water?

The lime content is often viewed very critically. However, lime naturally occurs in water and contributes significantly to its taste. Therefore, we do not remove the lime initially, but process it in such a way that it is bioavailable to our bodies and does not deposit undesirably. Calcium and magnesium are vital minerals for humans. Ultimately, the hardness of the water is a matter of taste and can, of course, be filtered out upon request.

Have you already worked with kombucha?

I've been a big kombucha fan for years and was even a speaker at the first Kombucha Summit. The kombucha community is super inquisitive and has remarkable cohesion. I sometimes miss that among water experts. For good kombucha, high-quality water is essential. You can taste the difference immediately. I work with several Berlin kombucha producers, and we install our Leogant water filters in their kombucha breweries. It's super exciting to accompany these manufacturers on their journey and to influence their different kombucha flavors.

Why do you think filtered water is better for kombucha fermentation?

Differences between filtered and unfiltered tap water

In my opinion, there should be a clear distinction between water for machines and drinking water for humans. Waterworks perform an excellent service, allowing us to access clear water at any time in everyday life. Nevertheless, their filtering system understandably cannot achieve spring water quality, as found in nature. If we consider water as a food, don't we all want to consume the highest possible quality?

• Here are two options: Either I buy high-quality spring water in glass bottles at an organic store, or I get a water filter and treat my tap water myself. 

• The Result: Depending on the filter system, the composition of the water can change. Which substances are actually reduced and to what extent depends on the specific filter and its tested performance. The effects of filtered water on taste and fermentation process depend on the initial water, the filtration method, and the respective fermentation conditions.

Effects of vitalized water on Kombucha

Experience shows that filtered and vitalized water significantly improves the fermentation process. Just as flowers and herbs last longer with vitalized water, the Scoby also benefits from premium water quality. The tea fungus grows faster, the alcohol content is different, and the Scoby is less susceptible to mold – resulting in a higher-quality, vitalized Kombucha.

Filtered water gives kombucha a special taste

Depending on the type of filtration and the conditions of the region from which the water originates, water quality also influences the pH value and thus the taste of kombucha. The water should not be too hard, but also not too soft. This is, of course, a matter of taste. The fewer minerals in the filtered water, the more acidic the water is. This affects the pH value during kombucha fermentation. For tea and coffee, slightly softer water is beneficial for taste. The tea fungus prefers it a bit more acidic. Decalcifying water can therefore have enormous disadvantages, which then also affect the taste of the kombucha.

What initial tips can you give our readers at home to improve their water quality for fermentation?


1. Always let the tap water run until it is noticeably colder. Most dirt is actually in the pipes and fittings. This can take 30 seconds on the ground floor, but up to 3 minutes on the 8th floor.

   
   
2. What also works initially is to boil the water if you don't have a filter. Then let it cool down and pour it through a coffee filter to remove suspended solids, limescale, and dirt. This naturally lowers the hardness level.
   
   
3. Semi-precious stones, such as rock crystal, amethyst, and rose quartz, can vitalize water. Simply place a few of them in a water jug with your water. It's best to always use tumbled semi-precious stones, as untumbled ones can harbor bacteria in their crevices and are difficult to clean.
   
   
4. Generally, it should be noted that bottled water is even less controlled than our tap water. Exceptions are some spring waters in glass bottles, which can usually be found in organic markets. Examples include Preußenquelle and St. Leonhard.
   
   
5. Start with the AVAIO countertop filter or another LEOGANT system. With the coupon code KOMBUCHERYXXLEOGANT2021X you will receive 10% off your first purchase in the LEOGANT online shop.

A strong water community as a future vision

What is your personal mission for the future?

In my post-Leogant vision, after 12 years in the "water business", I simply want to represent the entire exciting water topic on a meta-level. I want to build a strong water community, because working together is always better than working against each other. I also want to develop great concepts around the topic of water with competitors and raise people's awareness of the issue.