Smoke taint compounds
The compounds in smoke primarily responsible for taint are the free volatile phenols that are produced when wood is burnt. These compounds can also be absorbed directly by grapes and can bind to grape sugars to give glycosides that have no smoky aroma. Often these glycosides are described as smoke taint precursors. During fermentation (and also over time in barrel or bottle) these glycosides can break apart, releasing the volatile phenols into the must or wine, and allowing the smoky flavour to be perceived. These glycosides can also release the volatile phenols in the mouth during the drinking of wine, which may contribute to the perception of smoke taint.
Smoke taint analysis
AWRI Commercial Services is able to analyse grape, juice and wine samples for a range of volatile phenols and non-volatile smoke precursor compounds which may have a negative impact on wine quality. Understanding the levels of these marker compounds in fruit and/or wine may assist with making harvesting or winemaking decisions where there is a risk of smoke taint.
The AWRI recommends assessing the risk of smoke taint in grapes prior to harvest. Grape samples should be submitted for analysis of volatile phenols AND non-volatile smoke precursors (smoke taint panel). Tips for sampling, packaging and transport of grapes for smoke analysis are here: Grape sampling, processing and transport following vineyard smoke exposure.
In addition, a small-scale ferment of potentially affected grapes can be conducted at the same time. This allows wineries to conduct sensory assessment of the small-scale wines and gain further information to help determine the potential risk for smoke taint to develop in wine. A protocol for conducting small-scale ferments for this purpose is available here: Small lot fermentation method.
Juice and wine can also be analysed for smoke taint compounds.
|Prices per analysis|
|Analysis||Sample type||Cost (ex GST)|
|Volatile phenols + non-volatile precursors||wine||$247.00|
|Volatile phenols + non-volatile precursors||grapes||$295.00|
|Volume required – 500 g berries OR 100 mL wine|
For more information, please contact AWRI Commercial Services on (08) 8313 6600 or email@example.com.
Data interpretation and winemaking advice
Results from analysis of both the volatile phenols and glycoside precursors can be compared with baseline data from non-smoke affected fruit and wine to assist with determining potential risk of smoke taint. Low levels of volatile phenols and their precursors occur naturally in grapes that have not been exposed to smoke, so it’s important to assess their concentration, not just their presence or absence.
For assistance with data interpretation and winemaking advice to reduce the potential effects from smoke-related phenols, please contact the AWRI helpdesk on (08) 8313 6600 or firstname.lastname@example.org.
Further information can be obtained from the following links: