South Africa is experiencing quite understandable and soul-searching difficulty as it attempts to unravel claims made by prominent wine critic Michael Fridjhon that a number of producers have added flavouring agents in locally-grown sauvignon blanc wines. The country’s Wine and Spirit Board is responsible for the research into the issue, and it has chosen to focus on the levels of pyrazines in the wines, the group of molecules largely responsible for the grassy, herbaceous qualities of many sauvignon blancs. Pyrazines are generally more prevalent in cooler region wines, and it was the surprising grassiness of certain South African sauvignon blancs from warm to hot sites, that first caught the eye of Fridjhon and others. In my view there are significant problems associated with the notion that you can fingerprint regions with anticipated levels of pyrazines. It is possible to create high levels of pyrazine in hot region sauvignon blanc by harvesting a portion or indeed whole of the crop very early, especially if the canopy is allowed to shade fruit to a significant level. It mightn’t make a very good wine, but that’s not the issue here. Similarly, it is well known that through fruit exposure and leaf removal it is possible to make dramatic reductions in pyrazine levels in cooler climate fruit. Pyrazine levels in fruit are also very closely tied to vintage conditions. Even Barossa Valley cabernet sauvignon can exhibit significant pyrazine levels in cool seasons such as 1992. In my view it is not plausible to produce an intellectually credible ‘acceptable range’ of pyrazine levels for any given region or any given vintage, without it being so broad a range not to have any meaning. I believe that South Africa’s Wine & Spirit Board would be undertaking a very substantial legal risk in publicising the results of its research, which are believed to contain such ranges, as well as the specific levels of certain wines. It would be inevitable that many people lacking in scientific knowledge of this issue would draw the wrong conclusions, and in theory it is very possible that innocent growers and makers would be unjustly accused of wrongdoing. While this conclusion is contrary to that posed by Michael Fridjhon, I entirely agree with his suggestion to me that it would have been better to investigate the suppliers of the flavourants themselves. Personally, I cannot see any real accusation made on the basis of pyrazine levels alone being made to stick, guilty or not. As we see yet again, it’s always a difficult thing for an industry to investigate its own.
