This is a follow-up study to determine the effectives of grapevine-shoot extract as an alternative to sulphur dioxide (SO2) to preserve wines.
Shiraz grapes were harvested and fermented to dryness in Ganimede fermenters. No SO2 was added at crushing.
After completion of malolactic fermentation the wine was divided into three batches.
- 50 mg/l SO2 addition
- 50 mg/l total stilbene content Vineatrol addition (VIN-50)
- 100 mg/l total stilbene content Vineatrol addition (VIN-100)
Wines were stabilised for eight weeks at 0°C, racked, filtered and bottled under synthetic closure.
Wines were stored at 16°C, relative humidity of 80% for 12 months.
Wines were chemically and sensorially analysed after 12 months.
The VIN wines had better colour and more stable colour pigments on analysis than the SO2 treated wine.
The VIN-50 wine was similar in quality to the SO2 treated wine.
The VIN-100 wine scored lower on sensory analysis than the SO2 and VIN-50 wines.
Significance of the study:
The study showed that using a grapevine-shoot extract (Vineatrol) can be considered as an alternative preservative to SO2, allowing the production of low sulphur wines. The lower dose tested in this study (VIN-50) is recommended due to the negative sensory effect of the higher dose.