# Evaluation of Non-_Saccharomyces_ Yeast for Low-Alcohol Beer Production
## 3 Results and Discussion
### _Fermtative Analyses_
#### 3.2.2 Beer and Wort Physicochemical Characteristics  
The non-_Saccharomyces_ yeast species produced beers with the alcohol content in the range of 0.33-0.83% (\(v/v\)). The control strain of _S. cerevisiae_ US-05 produced significantly higher level of alcohol (3.61% (\(v/v\))). Based on the results, the non-_Saccharomyces_ yeast probably did not utilize the maltose or maltotriose. Most of the studied strains, with the exception of KL1, MP2, MP4, TD1, WO1, and WA1, produced less than 0.5% (\(v/v\)) ethanol (Table 3). These are the same strains which showed lower losses of mass during the fermentation process. Looking at the alcohol content, along with the sugar fermentation tests (Table 1), all of the strains show potential in obtaining a no-alcohol beer (<0.5%) without any significant process modifications. In case of using the strains that reach higher attenuation, a wort of lower extract might be necessary. Comparing with the other authors, [PERSON] [30] obtained a beer with significantly higher alcohol content from 12.5 \"Plato wort. The strains evaluated by the author, that is, _M. pulcherrima_, produced 33.8 g/L of alcohol, whereas the _T. delbrueckii_ strain produced 29.2 g/L of alcohol [30]. Low alcohol levels (\(\sim\)1% \(v/v\)) in a beer obtained from 11.1 \"Plato wort were found by [PERSON] et al. [31] for _W. anomalous_, _T. delbrueckii_, and _M. pulcherrima_ yeast strains. Similarly, [PERSON] et al. [60] reports 1.53% (\(v/v\)) beer from 12.3 \"Plato wort fermented by _W. anomalous_. The obtained results indicate that wine-related non-_Saccharomyces_ strains may be of particular interest in a screening of maltose-negative yeasts. Regarding the attenuation rate, the control strain US-05 had an apparent attenuation of 81.8%, which is consistent with the manufacturer's data [39]. All of the non-_Saccharomyces_ yeasts had attenuation in the range of 7.68-17.5% (Table 3). This further confirms that the studied yeasts did not utilize maltose nor maltotriose. Such attenuation rates are in line with the attenuation range of low- and no-alcohol yeasts found on the market. The real extract of the beers obtained with non-_Saccharomyces_ yeasts was expectedly high, in the range of 7.35-8.46 (\(w/w\)) (Table 3). Such a high content of residual extract is typical for low-alcohol beers obtained with biological methods [5]. The yeasts used about 1.0-1.5 \"Plato of the extract (Table 3). The color of most of the samples did not differ significantly from the color of the reference sample (S.C.). The only exception was a beer produced with the MP6 strain, which had the deepest color among the evaluated samples. This may have been related to the unique ability of some of the _M. pulcherrima_ strains to produce a red dye, called pulcherrimin [61]. The color of all of the beers was lighter compared to wort (Table 3). Lightening of a wort after a fermentation is typical [62]. Figure 2: Fermentation course of _S. cerevisiae_ US-65 and non-_Saccharomyces_ yeasts. The standard deviation of individual measurements is below 0.5%. Figure 3: Fermentation course of non-_Saccharomyces_ yeasts. The standard deviation of individual measurements is below 0.5%. \begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Alcohol**} & \multicolumn{2}{c}{**Original**} & \multicolumn{2}{c}{**Apparent Extract**} & \multicolumn{2}{c}{**Label Extract**} & \multicolumn{2}{c}{**Caloric Content**} & \multicolumn{2}{c}{**Density**} & \multicolumn{2}{c}{**Color [EGC]**} &