Monitoring Smoke Taint
Laboratory Services
Where to get my grapes/wine tested.
Today, there are two main NATA-accredited laboratories offering testing for smoke taint as a service to Victorian Wine businesses.
They each use slightly different methods for testing so results, whilst comparable are not interchangeable. Information on these differences can be found here. Due to these differences, we recommend that you are consistent in which laboratory you use in order to achieve consistency in interpreting your results against previous background levels. In times of real crisis, the best laboratory may be the one that is available.
Please note that there are often plant health and quarantine considerations for despatch of Victorian grape samples. Further information can be found here and in grape growing regions where phylloxera is present, here.
Preparing Samples & Where to Send Them
Timely analysis is critical but can be complicated, especially when smoke exposure continues between the time of sampling and harvest. We are fortunate in Australia to have a choice of laboratories that are able to test grapes for smoke taint indicator compounds and provide detailed client reports.
The following links outline each laboratory’s sampling and preparation recommendations:
Sample Receival Sites
During the devastating bushfire season of 2020, Wine Victoria, Agriculture Victoria, laboratories, regional associations, and wineries worked quickly to assemble a network of sample receipt sites across the state. These depots managed and coordinated vine heath protocols and documentation, plus despatch to the laboratories. These depots managed and coordinated vine health protocols and documentation, as well as dispatch to the laboratories. During the next large-scale fires, or trigger events, industry cooperation will again be necessary. Refer to your growers association about the coordination and management of sample dispatch sites.
Interpreting Results
What do the numbers mean?
Receiving your laboratory report is the easy part. Knowing what they mean and how to respond is trickier.
Unfortunately, there is no absolute guide to how a wine might taste or smell based on laboratory results, although work in this area is underway. The best – or sometimes the least worst – thing to do with exposed grapes depends on many factors. It can even be a variety, block or even wine style specific decision. Wine Victoria recommends that business managers consider the following to help navigate commercial relationships and assist with decision making:
- Wine style: The choice between sparkling, white, red and fortified winemaking can have a very large difference in the perceived taint level of the final wine and enable (or rule out) some very useful winemaking options to minimise it. For example, grapes harvested as early as possible for sparkling wine can potentially be a better option than harvesting red varieties at a later time for table-wine production.
- Harvest method: Harvesting by hand, or using different types of machinery, can influence the taint level in the final wine. It’s generally regarded that maceration should be kept to a minimum and temperatures kept as cool as possible when harvesting fruit that may be smoke affected.
- Release date of the wine: Perceived taint tends to become worse over time, so early release and/or fast selling wine styles can be a better option.
- Route to Market: Consider innovative methods of getting your wine to consumers, leverage existing relationships, individualised and focused marketing campaigns, with a faster release and consumption in mind.
Sensory Assessment Best Practice
Although laboratory testing remains the primary indicator for most (but not all) commercially related considerations, there is still a very important role for the sensory assessment of wines of concern. These are some of the most important assessments when it comes to the more subjective and vexxed questions around market acceptability to ensure value and quality for customers.
Some of the best advice on establishing trained sensory panels and industry best practice can be downloaded here.
A helpful video ‘Smoke sensory assessment procedure’ can also be seen here.
Small-lot Ferments
Although some businesses see value in them, small-lot (bucket) ferments can be limited in their accuracy and reliability and frustrating in their turnaround time for results. Nevertheless, they can be useful in decision making, some guidelines to carrying them out can be found here.
