Giampiero Scaglione

Study of the Grape Cryo-Maceration Process at Different Temperatures

This research aimed to determine the effects of cryo-maceration at different temperatures on polyphenol content during the winemaking process of Chardonnay wine. Samples of Chardonnay grapes were subjected to rapid cooling processes by direct injection of liquid CO2 to obtain final temperatures of 10.0, 8.0, 6.0 and 4.0 °C and yield different batches of grape mash. Subsequently, each batch underwent the winemaking process to produce four different wines. The wines obtained were characterized by chemical analyses. We observed higher extraction of polyphenolic compounds with low-temperature cold maceration, particularly when the temperature was reduced from 10.0 to 6.0 °C. Conversely, when the temperature was reduced below 6.0 °C, the increase in polyphenol content in wine was negligible, whereas CO2 consumption increased. Furthermore, a numerical simulation was performed to determine the pipe length, L0, after which the temperature was constant. This condition is very important because it guarantees that after the length L0, the thermodynamic exchange between liquid CO2 and is complete, eliminating the possibility of liquid CO2 pockets in the cyclone.