Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Wooden barrels have been the preferred method for oak maturation for wines, but the use of alternative oak products, such as staves and oak chips have increased in South Africa due to lower production costs. This study investigated the effect of different oak products used during fermentation and ageing on the sensory profile, degree of liking and perceived quality of a South African Chenin blanc wine. The different wine treatments included an unoaked tank control wine, wines matured in 5th fill barrels, wines matured in new barrels from three different cooperages, and wines matured in 5th fill barrels with stave inserts from two different cooperages.

Young white wines should be consumed within a short time after bottling to avoid loss of their fresh, fruity attributes. Shelf-life of white wines can be extended if they are stored under suitable conditions of time and temperature prior to consumption.

The effects of different oxygen and sulphur dioxide additions to South African ‘Sauvignon blanc’ musts were investigated. Oxygen addition without SO2 protection led to lower levels of certain volatile thiols in the wines, with a corresponding decrease in certain phenols and glutathione concentrations.

A total of 52 volatile compounds were measured in varietal Cabernet Sauvignon wines from four sites in Santa Catarina State (Brazil), over two consecutive vintages (2004 and 2005).

This work gives a summary of the most important programmes about viticultural « terroirs », developed on the « Côtes du Rhône » controlled appellation area for about twenty years.