Most conventional wine is as free of pesticide chemicals as its organic counterpart, a five-year survey has shown.
In most cases, analysis of 1,537 wines failed to find traces of synthetic compounds used to protect grapes from bacteria, fungi and insects, while just one in 25 had levels between 0.1mg and 0.8mg per litre.
The research was done by two Toronto University scientists, David Goldberg and George Soleas, who is also quality assurance director with state-owned retailers the Liquor Control Board of Ontario. It is published in the Journal of Wine Research . Soleas said: "It seems that pesticide residues have either broken down during fermentation or been filtered out."
The scientists tested wine and grape juice destined for fermentation, covering nine major wine-producing countries or regions.
Using mass spectrometric techniques, they looked for 26 common pesticides to a level of 30 parts per billion. In 44 wine samples, levels of chemicals exceeded 0.1mg per litre, but all were within European regulatory limits.
Steve Lewis, of wholesaler Vintage Roots, said organic wines were not just about avoiding artificial pesticides, fertilisers and other chemicals but about respecting the environment.