## 3 Results and Discussion
### Interpretation of Analysis in Various Fermentation Conditions  
During classical fermentation the first peak of the diacetyl concentration normally appears early. The concentration of diacetyl is then reduced when the yeast assimilates diacetyl and converts it enzymatically into acetone, which in turn is then metabolized. Diacetyl is thought to be a by-product of amino acid biosynthesis involving a relationship between amino acid biosynthesis and the formation of acetolactate, the diacetyl precursor. The second peak of diacetyl is explained by the decrease in fermentable sugars and a maximum activity of the yeast, hence a concentration of diacetyl proportional to the multiplication of the yeast and the degradation of fermentable sugars (production associated with growth). However, problems arise when continuous metabolic fluctuations lead to late production of diacetyl in amounts that create a 3 rd peak which may be due to the presence of a high concentration of diacetyl in the beer word. The higher levels of diacetyl resulting from late fermentation cannot be reduced below its gustatory threshold in the allotted time. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**ECH**} & **Oven** & **Intel Back** & **Pressure** & **RT** & **[Diacetyl]** \\  & **Temperature** & **Temperature** & **Column (atm)** & & **\#g/L** \\  & **(\({}^{\circ}\)C)** & **(\({}^{\circ}\)C)** & & & \\ \hline Reference & 70 & 150 & 39 & 5.6 & 16.5 \\ Sample & & & & & \\ \hline
1 & 70 & 70 & 39 & 5.602 & 17.06133 \\
2 & 13 & 70 & 39 & ND (5.58) & 0 \\
3 & 70 & 130 & 39 & 5.605 & 16.346 \\
4 & 130 & 130 & 39 & ND & ND \\
5 & 70 & 70 & 40 & 5.459 & 16.708 \\
6 & 130 & 70 & 40 & ND & 0 \\
7 & 70 & 130 & 40 & 5.457 & 16.70835 \\
8 & 130 & 130 & 40 & ND & ND \\ \hline \hline \end{tabular} ND: Not detected.  
\end{table} 
Table 4: The results obtained (response) after the application of the experimental design. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Experience** & **Factor 1** & **Factor 2** & **Factor 3** \\ \hline
1 & \(-1\) & \(-1\) & \(-1\) \\
2 & \(+1\) & \(-1\) & \(-1\) \\
3 & \(-1\) & \(+1\) & \(-1\) \\
4 & \(+1\) & \(+1\) & \(-1\) \\
5 & \(-1\) & \(-1\) & \(+1\) \\
6 & \(+1\) & \(-1\) & \(+1\) \\
7 & \(-1\) & \(+1\) & \(+1\) \\
8 & \(+1\) & \(+1\) & \(+1\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Application of factorial design (Three factors). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**N\({}^{\circ}\)Test** & **Factor 1** & **Factor 2** & **Factor 3** \\ \hline
1 & 70 & 70 & 39 \\
2 & 130 & 70 & 39 \\
3 & 70 & 130 & 39 \\
4 & 130 & 130 & 39 \\
5 & 70 & 70 & 40 \\
6 & 130 & 70 & 40 \\
7 & 70 & 130 & 40 \\
8 & 130 & 130 & 40 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The values of the factors studied with no coding unit. The total concentration of diacetyl in the beer at a given time during and after fermentation results from the combination of the rate of formation of \(\alpha\)-acetolactate, its rate of conversion, and the rate of reduction of diacetyl to 2,3-butanediol and acetone. Any latency of high diacetyl concentration resulting from late fermentation cannot be reduced until the beer undergoes further treatment, which may require prolonged maturation or other treatments or remedial measures to bring the final diacetyl concentration within the target specification of the desired final product (0-40) microgram per liter (Figure 1). In the process of stopping fermentation the word has been cooled to about 20 \({}^{\circ}\)C, is stripped under pressure to avoid foam production. This method produces a good quality beer with less than 0.2% alcohol by volume, but it requires precise analytical control. The yeast mass and alcohol content must be monitored every 8 h. In Super high gravity production, starting at 17 \({}^{\circ}\)P, 6.5 \({}^{\circ}\)P is obtained after centrifugation at about 0.4 \({}^{\circ}\)C and dilution, before or after final filtration, with desalted water to reach the desired alcohol and saccharometric level.