Commercial Services - Analyses
Smoke taint
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. The AWRI Analytical Service 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. If you suspect your fruit has been affected by smoke taint, please contact Randell Taylor, Trace Analysis Laboratory Supervisor on telephone 08 8303 6600 or email randell.taylor@awri.com.au
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.
| Analysis | Cost per sample (excluding GST) | ||
| 1-3 samples | 4-7 samples | 8+ samples | |
| 4-methylguaiacol and guaiacol in juice/wine | $93.00 | $88.00 | $85.00 |
| 4-methylguaiacol and guaiacol in grapes or leaves/canes | $106.00 | $102.50 | $97.50 |
| 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 | ||
*A handling fee of $25 exclusive of GST applies per invoice.
Response time may vary depending on sample numbers submitted and the current workload in the laboratory and refers to working days after receipt of samples.
Berries:
Package the berries in the berry containers provided. Please advise us how many containers you require. It is preferable to freeze the berries prior to despatch and to pack them so that they will remain frozen during the journey.
Juice:
Juice can either be submitted in the provided containers or in any other plastic vessel. You will need to freeze the juice prior to despatch and it is advisable to add a protective amount of SO2 (~200 mg/L) to prevent fermentation.
Wine:
Finished wine can be submitted in bottle.