Commercial Services - Analyses
Smoke taint
| Prices per analysis | ||
| Analysis | Cost per analysis (excluding GST) | |
| Analysis | 1-7 samples | 8+ samples |
| 4-methylguaiacol and guaiacol in juice/wine | $97 | $85 |
| 4-methylguaiacol and guaiacol in grapes or leaves | $115 | $105 |
| Volume required | 500 gm berries OR 50 mL juice OR minimum 20 g leaf/cane matter |
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| Target response time - 10 days | ||
The tainting of grapes and wine by bushfire smoke is an industry problem, highlighted by the events of 2003 in Victoria, NSW and WA, the 2006-07 fires in Victoria and Tasmania, and the 2009 bushfires in Victoria. Guaiacol and 4-methylguaiacol have been emphasised as important compounds contributing to 'smoky' taint in juice and wines, attributed to bushfire smoke. Commercial Services has an inexpensive and rapid method to accurately measure these compounds in grapes, juice and wine, with sensitivity to levels less than the sensory threshold, approximated at 6 µg/L in wine.
The most effective time to test levels of guaiacol and 4-methyl guaiacol in grapes is as close to harvest date as possible. It should be noted, however, that a finding of low concentrations in grapes at harvest is not a guarantee that any wine made from those grapes will be free from smoke taint. Guaiacol can be released during fermentation as a result of precursors and bound forms. Research is currently underway to characterize these precursors and to develop diagnostic or predictive assays to quantify the potential for release of guaiacol during fermentation, however such assays are not currently available.