No abstract

No abstract

No abstract

Bottle fermented sparkling wine in South Africa is known as Méthode Cap Classique which is based on the method used in France for Champagne. The use of cork, instead of a crown cap during the second fermentation in sparkling wine was investigated for its effect on the phenolic profile of wines. Phenolic acids susceptible to migration from cork into wine were studied in two-disc corks from three different commercial suppliers, coded as Cork A, Cork R and Cork C and a crown cap closure. Gallic, caftaric, caffeic and p-coumaric acids were quantified in all samples using a liquid chromatographic technique. Physicochemical parameters were also measured in the wine using a spectrophotometric technique. Total acidity and pH were not significantly different among the wines. Cork R wines were however significantly different in alcohol. Residual sugar for all samples was below the limit of detection. Gallic acid was significantly highest in Cork A wines, which indicates the contribution of Cork A to the concentration of this compound in the wine. Different cork types are assumed to release different concentrations of phenolic compounds. This may be due to differences in surface roughness of cork that would increase the surface area in contact with the wine. Therefore, corks from different origins (suppliers) could be used to bring about subtle differences to the wine.

Bottle-fermented sparkling wine producers are continuously striving to increase quality and produceniche products. One production tool that could be used is a cork closure instead of a crown cap closureduring the second fermentation and maturation on yeast lees. Anecdotal evidence suggests that thisleads to stylistic differences in the wine. Six pairs of South African bottle-fermented sparkling wines(Méthode Cap Classique), closed by either a cork or crown cap, were investigated. Analyses includedbottle pressure, infrared spectroscopy, phenolic acids, sensory attributes and CO2 kinetics. Generally,there were differences between the cork-closed and crown-capped wines. Cork-closed wines tended tohave lower pressure compared to crown-capped wines, albeit still well within legal requirements. Otherdifferences were evident in the infrared spectral data and in the polyphenol profile of the analysed wines.Levels of gallic, caftaric, caffeic and p-coumaric acids could be used collectively as marker compounds todifferentiate between cork-closed and crown-capped wines. The effect of the cork was also evident in thesensory attributes and CO2 kinetics. Cork-closed wines were judged to have smaller bubbles and a longeraftertaste. It was also shown that the cork-closed wines tended to lose CO2 from the glass slower after beingpoured than their crown-capped counterparts. The data tentatively support the anecdotal evidence thatcork can be used during the second fermentation and maturation on the yeast lees to change the style ofbottle-fermented sparkling wine.