## 3 Results and Discussion
### Key Arroma Compounds of Beers Produced with Non-Conventional Yeasts  
As a result of the conducted olfactometric analysis, 40 odour-active components were detected in the obtained beers (Tables 3-5). This was almost twice as many as the number of compounds (29) for which the calculated OAV exceeded one. The aroma notes have changed significantly from those detected in the hopped, unfermented word. In most cases, fruit and flower aromas were the most intense. Figure 3: Sensory analysis (QDA) of hopped unfermented word. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Compound** & **LRI 1** & & & & & & & & & \\ \hline EthJ Acetate & 598 & 0. & 0. & 0. & 0. & 0. & 0. & 1. & 0. & 0. \\ \hline
2-methyl-1-propanol & 608 & 0. & 0. & 0. & 0. & 0. & 0. & 0. & 0. \\ \hline Ethyl propionate & 691 & 0. & 1. & 0. & 0. & 0. & 0. & 0. & 0. \\ \hline
3-methyl-1-butanol & 723 & 1. & 1. & 1. & 0. & 0. & 0. & 1. & 1. & 1. \\ \hline Dimethyl disulfide & 743 & 0. & 0. & 0. & 1. & 1. & 1. & 0. & 0. \\ \hline Isobutyl acetate & 755 & 1. & 0. & 0. & 0. & 2 & 1 & 1 & 0. & 0. \\ Ethyl btanoate & 784 & 0. & 0. & 1. & 1. & 0. & 1. & 0. & 0. \\ Ethyl lactate & 794 & 0. & 0. & 0. & 1. & 0. & 0. & 0. & 0. \\ \hline
4-methyl-1-pentanol & 819 & 0. & 0. & 1. & 0. & 1. & 0. & 0. & 0. \\ Ethyl-2-methylbutyrate & 855 & 2 & 0. & 0. & 2. & 0. & 0. & 0. & 0. \\ \hline
3-Methylbutyl acetate & 856 & 0. & 0. & 0. & 0. & 0. & 0. & 0. & 0. \\ \hline Methanol & 866 & 0. & 0. & 0. & 0. & 1. & 0. & 0. & 0. \\ Ethyl pentanoate & 882 & 1. & 0. & 0. & 0. & 0. & 0. & 0. & 0. \\ Ethyl 2-Leadenicenic & 900 & 0. & 0. & 0. & 0. & 0. & 0. & 0. \\ \hline
3-Methyl-1-hexanol & 918 & 0. & 0. & 0. & 1. & 0. & 0. & 0. & 0. \\ \hline Dimethyl disulfide & 933 & 0. & 0. & 0. & 1. & 0. & 0. & 0. & 0. \\ Ethyl 4-methylmethmethanate & 944 & 0. & 1. & 1. & 1. & 1. & 2. & 2. & 1. \\ Ethyl hexanoate & 976 & 1. & 1. & 1. & 1. & 0. & 0. & 0. & 0. \\ \hline Benzonoacetaldehyde & 1005 & 0. & 0. & 0. & 1. & 0. & 0. & 0. & 1. & 0. \\ Acoteborne & 1040 & 0. & 0. & 0. & 0. & 0. & 0. & 1. & 0. \\ \hline
1-Ctained & 1060 & 0. & 0. & 1. & 0. & 0. & 0. & 0. & 0. \\ Nonanal & 1072 & 0. & 1. & 0. & 1. & 0. & 0. & 0. & 1. \\ \hline Phenylethyl Alcohol & 1085 & 1. & 2 & **24** & 2. & 2. & 2. & 2. & 1. \\ \hline cis-Rose oxide & 1095 & 0. & 0. & 0. & 1. & 1. & 0. & 1. & 0. \\ \hline
2-Phenylethyl formate & 1112 & 0 & 0 & 0. & 0. & 1. & 1. & 0. & 0. & 0. \\ \hline
1-Nonanol & 1159 & 0 & 0. & 0. & 0. & 0. & 0. & 1. & 2. & 0. \\ Ethyl octanoate & 1174 & 1 & 1 & 1. & 1. & 1. & 1. & 0. & 1. & 1. \\ \hline Decanal & 1183 & 1 & 1 & 0. & 0. & 0. & 0. & 0. & 0. & 1. \\ \hline
4-Orthello & 1207 & 0 & 0 & 0 & 0 & 0 & 0 & 0. & 0. & 0. \\ \hline
2-Phenylethyl acetate & 1218 & 0. & 0. & 1. & 0. & 0. & 0. & 0. & 1. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Colour-active compounds and heatmap of their intensities detected by GC-O in beers produced with different yeast. The roasted notes dominant in the unfermented word were significantly reduced. Yeast activity plays an important role on the levels of Strecker aldehydes. In fact, they are reduced to alcohols during fermentation, and on the other hand, the SO\({}_{2}\) formed during the process can bind these molecules, thus contributing to a reduction in the perceived \"aged character\" [33]. In peers, two higher alcohols--2-methylpropanol and 3-methylbutanol--were responsible for roasted notes [Table 3]. Their aroma was described as bready, in higher concentrations of alcoholic or solvent. Higher alcohols are, after ethanol, the volatile compounds found in peers in the largest amounts. They are formed during fermentation from the corresponding amino acids (except 1-propanol). Their influence on the aroma of beer is not only direct, but they are also important precursors for other aroma components, e.g., esters [3]. The higher concentrations of the compounds discussed were found in peers obtained with the participation of _W. anomalous_, the least after fermentation with _Z. bailii_.