The skins and seeds of grapes are included with the juice during red wine fermentation. As the fruit macerates and fermentation commences, the CO2 created by the fermentation causes skins to rise to the top and form a cap. To extract color, tannin, and other flavor compounds present in the skins, the cap is broken-up and pushed back into the fermenting wine to increase contact between the skins, seeds and juice. Breaking up the cap also helps maintain the health of the fermentation by regulating the temperature and promoting microbial stability. The process introduces oxygen, which helps maintain a healthy fermentation. The three common techniques of cap management typically used are Punch Down, Submerged Cap and Pump Over.
