## 3 Results and Discussion
### Analytical Results
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameters** & \
\begin{tabular}{c} **Wine Tank with** \\ **Pneumatic Cap Breaking** \\ \end{tabular} & **Standard Deviation** &
\begin{tabular}{c} **Wine Tank with** \\ **Pump-Over System** \\ \end{tabular} & **Standard Deviation** \\ \hline Density & 1.05 g/mL & 0.06 & 1.03 g/mL & 0.05 \\ Reducing weight & 132 g/L & 6.25 & 79 g/L & 3.79 \\ Effective degree & 5.93\({}^{\circ}\) & 0.231 & 8.98\({}^{\circ}\) & 0.34 \\ O.D. 420 & 2.00 & 0.101 & 1.94 & 0.08 \\ O.D. 520 & 3.20 & 0.165 & 2.89 & 0.13 \\ O.D. 620 & 0.80 & 0.036 & 0.80 & 0.03 \\ Dye intensity & 6.00 & 0.247 & 5.63 & 0.23 \\ Tonality & 0.60 & 0.027 & 0.67 & 0.02 \\ Total polyphenols & 1.48 mg/L & 0.083 & 1.64 mg/L & 0.09 \\ pH & 3.50 & 0.139 & 3.47 & 0.17 \\ Total acidity & 7.00 g/L & 0.381 & 6.85 g/L & 0.29 \\ Pick up time & 72 h & & 96 h & \\ (hours after hat break) & 72 h & & 96 h & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Analytical evaluations carried out on musts in wine tanks equipped with the different circulation systems studied (mid-fermentation). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameters** & \
\begin{tabular}{c} **Wine Tank with** \\ **Pneumatic Cap Breaking** \\ \end{tabular} & **Standard Deviation** &
\begin{tabular}{c} **Wine Tank with** \\ **Pump-Over System** \\ \end{tabular} & **Standard Deviation** \\ \hline Density & 0.99 g/mL & 0.05 & 0.99 g/mL & 0.03 \\ Reducing weight & 0.60 g/L & 0.02 & 0.60 g/L & 0.02 \\ Effective degree & 13.88\({}^{\circ}\) & 0.73 & 13.70\({}^{\circ}\) & 0.76 \\ O.D. 420 & 2.11 & 0.08 & 2.00 & 0.10 \\ O.D. 520 & 3.70 & 0.24 & 3.00 & 0.16 \\ O.D. 620 & 1.00 & 0.03 & 1.00 & 0.04 \\ Dye intensity & 6.81 & 0.32 & 6.50 & 0.36 \\ Tonality & 0.60 & 0.02 & 0.66 & 0.03 \\ Total polyphenols & 2.01 mg/L & 0.11 & 1.85 mg/L & 0.10 \\ pH & 3.60 & 0.15 & 3.60 & 0.15 \\ Total acidity & 7.00 g/L & 0.29 & 7.00 g/L & 0.27 \\ Pick up time & 120 h & & 144 h & \\ (hours after hat break) & & & 144 h & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Analytical evaluations carried out on musts in wine tanks equipped with the different circulation systems studied. End of fermentation. the first fermenter. In addition, in the pneumatic system, the solid parts of the must were always in circulation (not forming the cap), which favoured a higher extraction. The above can be explained by the dynamics of pneumatic cap breaking applied to the primitive grapes from which the crushed grapes were obtained in the fermentation studied. In this system, the cap breakage is achieved by cracks created in the mass by air injected simultaneously from different points on the side of the tank; the air penetrates into spaces where it is much more difficult for the liquid to penetrate, causing the cracks to widen, allowing the liquid phase to rise and the cap to break in different areas. In the case of Primitivo grapes, which are characterised by very thin skins, no cellular or extracellular surfaces can be identified as barriers to the escape of liquid, so a less invasive extraction is desirable. On the other hand, the fact that, with this type of pressing, the chemical and physical characteristics of the wine obtained with the pneumatic system are comparable to those of the wine obtained with mass circulation by pumping over is certainly a positive result, both in terms of the very favourable functional and energetic performance and in terms of the margins for improvements that characterise this system. For example, the size, frequency, and sequence of the insufflations can be adapted to the characteristics of the crushed grapes undergoing fermentation, in order to obtain an optimum coupling of the resonance frequency of the liquid with that of the solid and to obtain the desired maceration.