# The Influence of Fermentation Vessels on Yeast Microbiota and Main Parameters of Sauerkraut
## Results and Discussion
### The Influence of the Vessel Used for Fermentation on the Yeast Microbiota of Sauerkraut  
Due to the large differences in the composition of the yeast microbiota during the fermentation of sauerkraut in stonewarse vessels, observed in the first stage of the research in relation to previous experiments [5], in the second stage of the research, the influence of the vessel used for fermentation on the qualitative and quantitative composition of yeast and other selected parameters important for the quality of sauerkraut was analyzed. Glass jars were used, which prevent air from entering and in which anaerobic conditions are quickly created, and stonewarse vessels in which the surface was covered with a plastic foil pressed with a pressure stone. The most popular variety of cabbage used for pickling in Poland--Galaxy--was used for fermentation. The initial yeast content in the batch was 1.9 log cfu/g (Figure 2), the average amount found in previous analyses [5]. [PERSON] and [PERSON] detected much higher amounts of yeast (3.5 log cfu/mL) in Turkish cabbage used for fermentation [19]; however, according to [PERSON] [20], in subsequent growing seasons, there may be very large differences in the level of various microorganisms (including yeast) on the surface of fresh cabbage. Statistically significant differences between the samples were observed on the second day of fermentation (Figure 2), when inhibition of yeast cell growth at the level of 2.2-2.4 log cfu/g was observed in glass jars, while in stonewarse vessels the abundance continued to increase, exceeding 3 log cfu/g. In the case of stonewarse vessels, the maximum of yeast growth took place on the fourth day of fermentation, while in jars the highest number of yeast cells was recorded on the third and fourth days, and the number of yeast cells detected in stonewarse vessels was over six times higher than in the jars. In the following days, there was a significant decrease in the number of yeasts; from the tenth day, yeast was no longer detected in the jars, while a small amount was found in the stonewarse vessels until the  
Figure 2: Changes in the amount of yeast during the fermentation of Galaxy cabbage in stonewarse vessels and glass jars. Values with different roman letters (a–f) indicate statistically significant differences at \(p<0.05\). end of fermentation. A similar phenomenon was observed by [PERSON] et al. [21], who found the maximum level of yeast on the fifth day of sauerkraut fermentation, and its content decreased in the following days. However, they obtained a significantly higher yeast count during and at the end of fermentation, which could be related to the high initial amount of yeast in fresh cabbage. Differences in the amount of yeast depending on the vessel used for fermentation may indicate different conditions, which may also have a significant impact on the qualitative composition of the microorganisms present (Figure 3). An important observation during fermentation was the presence of film-forming yeast on the surface of the stoneware samples, while they were not observed in the jar. Characteristic colonies of microorganisms morphologically resembling mold are formed on the surface of the fermenting vegetables and perfectly tolerate high salinity, and their development may contribute to the deterioration of the quality of the product obtained. Over-proliferation of yeast can also create an undesirable yeast/fungal taste. The species most often associated with this phenomenon are the yeast _Candida mycoderma_ and the mold _Galactomyces geotrichum_[4].