Cold maceration in production of high quality wine

The cold maceration of grapes allows one to produce wines characterised by a deep colour and an aromatic profile strongly connected to its zone of production as well as to the variety of grapes employed (typical wines). The temperature reduction could be obtained using an heat exchanger or by direct addition of a cryogen (CO_2,liquid and/or CO_2,solid, N_2,liqiud) to the grapes crushed. Because of the very low temperature of the cryogen (T Lt 0degC), its contact with berries induces the cellular crash which promotes the later liberation of cellular components (phenols, mannoproteins, sugars, aromatic compounds) in the liquid phase. Moreover, the high cryogen content of the gaseous phase should limit remarkably the oxidation of phenolic and aromatic compounds. Some grapes parcels coming from the same vineyard were cold macerated using an heat exchanger or by addition of CO_2,solid, to verify the existence of compositional differences between wine coming from different macerations. The experimental results seem to underline cellular crash is able to improve the extraction of coloured and aromatic substances so to produce wines characterised by typical flavours and organoleptic characteristics.