In 2007 and again in 2009 we did not make any wine because the vineyard was blanketed with smoke from bushfires. Noxious chemicals in smoke bind to grape skins. When the grapes are crushed, especially if the juice is allowed to remain in contact with the skins for an extended period as is generally the case when making Pinot, these chemicals contaminate the wine imparting to it an acrid back-taste reminiscent of old ashtrays.
So when Prof Ian Porter from La Trobe University asked if we would like to help with a study to establish how much smoke it takes to contaminate wine to the point where it becomes noticeably unpleasant, we readily agreed. The Department of Airs and Waters and Whatnot – D, um, DWL, DSE that was – were planning to burn large tracts of bushland near out vineyard, but very kindly (thank you Brendan Purcell) arranged to delay the burn-offs until after we’d picked our grapes. At Ian’s suggestion, we left a couple of rows unpicked so we could take grape samples before, during and after their exposure to smoke. I then made small batches of wine from these grapes which the Australian Wine Research Institute is in the process of analysing. This is the first time before, during and after samples have been secured and it is hoped the results will establish what level of smoke exposure makes wine unpalatable.