PRINT THIS PAGECap management during pinotage fermentations
Marais, J. (2003). Effect of Different Wine-Making Techniques on the Composition and Quality of Pinotage Wine. II. Juice/Skin Mixing Practices. S. Afr. J Enol. Vitic., 24(2), 76-79.
The effect of juice/skin mixing practices during fermentation in the production of Pinotage wines was studied over three vintages.
The fruit was harvested from the same block and split into similar sized lots. During fermentation the cap and juice were mixed by punching down, pumping over or rotor action. Each treatment was conducted both hourly and three hourly between 7 a.m. and 5 p.m. The control was the hourly punch down.
Post fermentation no malolactic fermentation or oak treatment.
Polyphenols
The wines were analysed for total flavonoids, total tannins and total anthocyanins.
In the bottled wine the punch down and rotor treatments gave similar results and the pump over lower levels. The lower level in the pump over sample may have been due to greater polymerisation through greater oxygen contact and the softer nature of the treatment.
Esters
Wines were analysed for iso-butyl acetate, iso-amyl acetate, hexyl acetate, ethyl butyrate, ethyl hexanoate, ethyl octanoate and ethyl decanoate.
The rotor treatment produced higher levels of acetate.
Wine quality
The wines were analysed at six months of age for berry/plum intensity and overall wine quality.
The highest qualities were found in the punch down and rotor treatments.
Wines made by the pump over technique were however softer in structure.
Frequency of skin/juice mixing
Differences between the one hourly and three hourly treatments were not significant.
References