WINETECH Technical Yearbook 2021

OENOLOGY RESEARCH | OCTOBER 2021

Adding antioxidants to Sauvignon blanc musts (PART 2)

CARIEN COETZEE: Basic Wine, Stellenbosch KEYWORDS: Antioxidants, Sauvignon blanc, volatile thiols.

MATERIALS AND METHODS Hand harvested Sauvignon blanc grapes from two different sites located in the Marlborough region in New Zealand were used in the study. It was noted that, due to suboptimal weather conditions, the bunches were of relatively poor condition with berry damage and mould. Small scale experiments were conducted and four treatments were applied in the must phase prior to pressing. Sulphur dioxide (SO 2 ) (20 mg/L) were added prior to pressing for all 2. 20 mg/L GSH. 3. 100 mg/L GSH. 4. 20 mg/L GSH + 100 mg/L ascorbic acid. The juices were inoculated with VIN7 and fermented to dryness. treatments. 1. Control.

THE ADDITION OF ANTIOXIDANTS to Sauvignon blanc must was investigated in two trials conducted by New Zealand researchers (Lyu et al ., 2021). The main findings of this study are reported in this two-part article. INTRODUCTION In part one of the two-part article, the effect of the addition of antioxidants, sulphur dioxide and glutathione (GSH), as well as two commercial inactivated dry yeast products were discussed. The additions were made to the must prior to pressing and the volatile thiols of the resulting wines measured. In part two, the effect of varying concentrations of GSH, as well as the addition of ascorbic acid are reported. Trial 2: Comparing sulphur dioxide (SO 2 ), GSH and ascorbic acid

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