# Effect of Ultrasound on Fermentation of Thick Molasses Worts by Distiller's Yeast
## 3 Results and Discussion
### Wort Analysis
#### 3.2.4 The Influence of Ultrasound Treatment on Ethanol Formation in Molasses Wort  
The main application goal of research on alcoholic fermentation, which the results presented in this study are a part of, is to maximise the efficiency of ethanol production from sugars contained in various raw materials. Also, the ethanol production process is expected to be as short as possible for economic reasons. The following table (Table 7) shows the final ethanol concentrations obtained after 72 h of fermentation. A 3-day fermentation is a typical time in Polish distilleries; hence, we adopted it in our experiments. Since the final ethanol concentration alone does not reflect the efficiency of the ethanol conversion process, the values of this second parameter obtained in individual experiments are summarised in the figure below (Figure 4). When preparing the manuscript, we decided that the notable results we obtained show the impact of ultrasonic treatment on the most crucial indicator of the economic efficiency of the ethanologenesis process--the concentration and the resulting ethanol yield. Both of these summaries are presented below. For the 18 \({}^{\circ}\)Blg wort, the final ethyl alcohol concentrations were in the range of 51.82 \(\pm\) 0.91 g/L-56.85 \(\pm\) 1.22 g/L for ER yeast and 48.81 \(\pm\) 0.93 g/L-54.97 \(\pm\) 0.63 g/L for TD yeast (Table 7). The results also show that sonification caused a statistically significant increase in the final ethanol concentration. However, intensifying the treatment by increasing the ultrasound amplitude did not translate into an increase in the final ethanol concentration. A similar trend was observed for wort with an initial density of 22 \({}^{\circ}\)Blg, with ethanol concentrations predictably (due to the higher sugar content) higher than those obtained for 18 \({}^{\circ}\)Blg wort (Table 7). However, it must be emphasised that to assess the proportionality of this increase, it was necessary to compare the results expressed in the percentage ethanol yield graph we presented. The slight increase in wort density from 22 to 24 \({}^{\circ}\)Blg translated into a marked decrease in the final ethanol concentration. The maximum values of this parameter after 72 h of fermentation were 56.15 \(\pm\) 0.77 g/L for the ER us75 sample and only 37.38 \(\pm\) 0.92 g/L for the TDus75 sample (Table 7). This trend is even more visible as a decrease in the efficiency of the ethanologenesis process, as is shown in the graph (Figure 4). The total ethanol yield in the 24 \({}^{\circ}\)Blg wort did not exceed 70% for the ER us75 sample and was only about 10% for the ER us75 sample. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Initial Extract** & **18 \({}^{\circ}\)Blg** & **22 \({}^{\circ}\)Blg** & **24 \({}^{\circ}\)Blg** \\ \hline  & & **g/L** & \\ \hline ER contr & 51.82 \(\pm\) 0.91 & 61.67 \(\pm\) 0.74 & 44.28 \(\pm\) 1.00 \\ \hline ER u50 & 56.85 \(\pm\) 1.22 & 65.64 \(\pm\) 1.92 & 48.23 \(\pm\) 0.98 \\ \hline ER u75 & 56.22 \(\pm\) 1.43 & 66.11 \(\pm\) 1.16 & 56.15 \(\pm\) 0.77 \\ \hline TD contr & 48.81 \(\pm\) 0.93 & 53.76 \(\pm\) 1.26 & 23.54 \(\pm\) 0.49 \\ \hline TD u50 & 54.97 \(\pm\) 0.63 & 61.12 \(\pm\) 1.42 & 29.57 \(\pm\) 1.20 \\ \hline TD u75 & 52.45 \(\pm\) 1.35 & 56.89 \(\pm\) 0.85 & 37.38 \(\pm\) 0.92 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Final ethanol concentration after 3 days of fermentation of wort of different densities by two strains of distiller’s yeast, depending on the sample’s sonification. 45% for the TD us75 sample, which is particularly evident when compared to the yield results observed for the 18 \({}^{\circ}\)Blg wort. A comparison of the fermentation performance of words with different densities shows that the assumed fermentation time of 72 h was too short for samples with a density higher than 18 \({}^{\circ}\)Blg. Especially in the case of 24 \({}^{\circ}\)Blg wort, the inhibitory effect of the osmotic pressure of high-density wort was noticeable.