Grape pomace
It is the solid part of the grape left after vinification and pressing. It is composed of the grape stalk, the skin and seeds in extremely variable proportions depending on the vintage, the state of maturation, of many environmental and cultivable circumstances and, finally, the type of vinification and pressing. It represents from about 7 to 14% of the weight of the grapes. The grape pomace is distinguished in either white or red depending on the quality of vintage of origin and whether virgin or sweet, if it was immediately separated from the must during vinification or semifermented, if it was derived from a short fermentation and finally fermented when it remains in contact with alcoholic fermentation. The virgin and semifermented pomace cannot be distilled straight away as they contain very little alcohol and need to be siloed quickly to complete, out of air contact, the sugar transformation into alcohol. If the ensilage is delayed and not well looked after, the pomace rapidly ferments with a notable rising temperature and, the alcohol produced is partly evaporated and partly transformed into acetic acid, with consequential economic and qualitative damage. The fermented pomace can be distilled straight away ensilaging, when necessary, the excess depending on the daily working capacity of the installation and finally avoiding its deterioration.
