Impact of minerals and nitrogen on kombucha production
In this study, we aim to identify the minerals and nitrogen compounds required by the yeast and bacterial cells in the SCOBY (Symbiotic Culture of Bacteria and Yeast) during kombucha fermentation. Without the right balance of these nutrients, the microbial cells may become fatigued and depleted, leading to inefficient fermentation and a delayed or disrupted production process. We will investigate the influence of various minerals and nitrogen compounds—both individually and in combination—on fermentation performance. This will be assessed by systematically analysing the fermentation outcomes using laboratory data, allowing us to map the effects of each nutrient on the process and the final product.
Kombucha is a non- or low-alcoholic sparkling beverage made from a fermented tea solution. Similar to beer fermentation, it is suspected that the mineral composition of the water used for tea preparation and the presence of nitrogen compounds influence the fermentation process and the final product.
Kombucha fermentation is carried out using a symbiotic culture of bacteria and yeast, known as a SCOBY. Nitrogen compounds and minerals are key factors in fermentation by yeast and acetic acid bacteria. Fermentation is a metabolic process involving hundreds of reactions within the cells of yeast and bacteria. Each reaction is influenced by various factors such as pH, temperature, pressure, and the presence of sugars.
The nutrients available to the microbial cells—particularly minerals and nitrogen compounds—also play a crucial role. These nutrients determine how cells absorb and metabolise substances, enabling growth and survival through a cascade of biochemical reactions. If cells do not absorb sufficient nutrients, they cannot carry out the necessary fermentation reactions. This leads to what is known as slow or sluggish fermentation, where the process starts too slowly and results in disrupted metabolite formation. Consequently, kombucha may develop too few, too many, or undesired flavour and aroma compounds.
When fermentation proceeds smoothly, the bacteria and yeast exhibit healthy growth and vitality. However, for kombucha, there is currently no available data or literature on:
- the optimal mineral composition of the water used, and
- the necessary nitrogen compounds for fermentation with a SCOBY.
This leads to the following research questions for kombucha producers:
- Which minerals and nitrogen compounds can promote efficient kombucha fermentation?
- How can these be added to the tea preparation?
- What is their effect on the final product?
The overall aim of the project is to achieve a smooth and rapid fermentation process by the SCOBY through water correction and/or the addition of ingredients (minerals and/or nitrogen compounds) during tea preparation.
SCOOBYDOOO!
Kombucha is a delicious, slightly sour beverage made from sweetened tea and a symbiotic culture of bacteria and yeast, commonly known as a SCOBY. The SCOBY acts as a starter culture for the fermentation of kombucha.
During fermentation, the bacteria and yeasts in the SCOBY convert sugars into various by-products, including carbon dioxide, gluconic acid, acetic acid, and small amounts of alcohol. These compounds give kombucha its characteristic flavour and sparkling texture.
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