Decanter World Wine AwardsSulphur Dioxide 'good for grapes': study
- Thursday 1 September 2011
[Picture: Ben Mills] Sulphur Dioxide: good for grapes?
A study by the University of Western Australia has found that sulphur dioxide could actually have a positive effect on a grape berry's composition.
The chemical is used widely in winemaking worldwide for a variety of purposes, and is very much bête-noire of the burgeoning natural wine movement, which considers it unnecessary.
Assistant professor Michael Considine at the university told Decanter.com, 'The exciting thing is that sulphur dioxide increases the antioxidant levels and antifungal levels in the berry to improve its own defense responses. It primes the plant to help itself.'
Considine admitted there was 'irrefutable evidence that sulphur dioxide has ill-health effects on humans' including skin and respiratory problems.
But, he said, once more was understood about vines and sulphur dioxide, finding an alternative would be possible.
'If we can understand a little better how the plant is responding to sulphur dioxide than we can tailor alternatives, which would not have ill-health connotations.'
Considine suggested ozone could be a possible alternative, as well as lysozyme, which some wineries already use instead of sulphur dioxide to inhibit the malolactic fermentation.
The research was conducted on table grapes but could far-reaching consequences for wine producers in their search to further reduce sulphur levels.
Have your say!
tsen tsai
February 01 17:56
sulfur is an natural occurring element occurring in many plants and vegetable...get over it and enjoy non oxidized wine!!
John Casey
February 01 05:40
Sulfur dioxide in wine acts as an anti-oxydasic, anti-oxidant and acetaldehyde antagonist. It is an essential ingredient of merchantable wine. At levels beow the sensory threshold, there are no ill-effects on the respiratory system. After all, the human body produces and metabolises several grams of sulfur dioxide every day.
mike
December 06 08:14
JohnMc
A university professor, not a natural winemaker, suggested ozone as a possible SO2 alternative. Natural winemakers are seeking to reduce or eliminate additives, not replace them. Different methods, including taking advantage of the protective colloids present in higher solid fermentations might be considered as a 'natural' alternative to SO2 dependent methods.
Micko247
November 27 05:46
Hi JohnMc,
SO2 acts as either oxidising or reducing agent, depending on redox potential of reactants. In this case, evidence showed the effect was oxidising. Ozone and UVB have previously been shown to increase antioxidant defences in plants and fruit.
Workplace exposure limits are lower for ozone than SO2 but ozone is commercially effective below these limits, e.g. for strawberry.