Sulphur free red wines through the use of grapevine-shoot extract

This is a follow-up study to determine the effectives of grapevine-shoot extract as an alternative to sulphur dioxide (SO₂) to preserve wines.

Project layout:

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.

Results:

• 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 SO_2, 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.

Reference: http://www.sciencedirect.com/science/article/pii/S0308814617315881

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