Project Number
WW WDT 06-02
Project title
Characterising different red grape cultivars in terms of certain wine parameters
Project leader
Du Toit, W J
Institution
University of Stellenbosch. Department of AgriSciences. Department of Viticulture and Oenology
Team members
Bindon, K
Visser, C T
Project description
In conjunction with the KWV different clones were selected from certain red cultivars from the KWV foundation unit in Stellenbosch. All clones from the same cultivar grow in the same block. Grapes were harvested at roughly the same ripeness (between 24-26 Balling). These were Pinotage (clones: PI 45, PI48), Merlot (clones MO45, MO184, MO346), Cabernet franc (clones CF 212, CF213, CF 214, CF 623) and Cabernet Sauvignon (clones SH 1, SH12 , SH 470. The pH, TA and sugar were determined and phenolic analysis on the berries included total phenolics, total tannins and total anthocyanins. Standard winemaking techniques were used and from each clone, wine was made in triplicate. Wine was put through alcoholic and malolactic fermentation. Analyses showed that there were differences regarding total acids: malic acid and alpha amino acids and ammonia between the clones at harvest. Phenolic analyses showed that anthocyanin concentrations differed between clones of Merlot, Cabernet franc and Cabernet Sauvignon, with differences in tannin concentrations observed between clones of Merlot, Cabernet Sauvignon and Shiraz. Phenolic analyses on the clone wines will include total tannins, total anthocyanins, colour intensity, modified colour intensity, total anthocyanins and sulphur dioxide resistant pigments.
Presentation(s)
Du Toit, W J, Jordaan, J, Keulder, D, Oberholster, A and Bindon, K A. 2006. Optimal ripeness and tannin additions. Winetech VinPro Information Day: Optimal Ripeness. October, South Africa.
Du Toit, W J, Jordaan, J and Bindon, K A. 2006. The effect of clone differences on grape and red wine phenolic composition. Paper presented at the 3rd International Congress of the South African Society for Viticulture and Enology. 28-30 July, Cape Town, South Africa.