Prepn of red and rose wines - by sepg skins from pulp and juice, and extracting colouring matter from the skins

摘要

Fermentation process for making wine from grapes having coloured skins comprises (a) de-stemming and crushing the grapes, (b) pressing the grapes to separate the juice and pulp from the skins, (c) placing the juice and pulp in a container having access to the ambient atmosphere (d) adding yeast to cause fermentation, (c) subjecting the skins to the action of an aq. mixture of (i) citric acid and (ii) hydrochloric, sulphuric or phosphoric acid until a substantial amount of colouring substance is transferred from the skins to the aq. soln. and sepg. the skins from the extract, (f) partially neutralizing the coloured extract by neutralizing the acid with a non-toxic material (g) allowing the yeast to ferment the juice and pulp to wine, with CO2 and heat being allowed to flow to the ambient atmos. and (h) adding the partially neultralized coloured aq. extract to the juice and pulp prior to the completion of fermentation. By removing the skins before fermentation the formation of a compact nut of skins on the liquid surface. The formation of a mat prevents heat and CO2 escaping which leads to deterioration of the final wine quality and may encourage the growth of undesirable bacterial. Previously the mat has had to be broken up physically and thus the present process requires less labour.