March 2010

Stuck on sulfur?
Message in a bottle
All about salt
Tracking tropical
Green talent
London tastes Australia
New chair

Stuck on sulfur?

If you’ve sprayed your grapes with sulfur and need to harvest now within the 30 day withholding period, the AWRI has some advice to help you.

If you are concerned about the effects of sulfur on yeast and fermentation, access our eBulletin which offers easy-to-follow advice to reduce your risk of problems. Contact Marcel Essling from the AWRI’s Viticulture team on (08) 8313 6600 for more information.

Message in a bottle

Did you know that the loss of fresh fruit characters and the development of ‘reductive’ and ‘oxidised’ characters could be the result of poor management of oxygen transmission through wine bottle closures or packaging? Commercial Services can now accurately measure the oxygen transmission rate (OTR) of your packaging non-destructively.

Brand new and proven to be highly reproducible, the method directly measures the real OTR of different closures and packaging solutions while they are in contact with wine. It can be used to check ‘problem’ bottles from a particular batch or weak points in bulk container packaging. Email AWRI Commercial Services or call on (08) 8313 6600 to test your closures, or access the Commercial Services Packaging solutions webpage for more information.

All about salt

Are you confused about salt? Do you know whether to measure sodium or chloride concentration? What’s the legal limit? Is there a link between high salt levels in petioles (leaf stems) and the amount that ends up in wine?

The AWRI’s salinity experts are here to help. They recommend that you measure chloride ion concentrations to stay within legal limits. The Australian and New Zealand Food Standards Code has set the limit at 1000 mg/L of soluble chlorides expressed as sodium chlorides that equates to 607 mg/L of choride ion.

As for petioles – taken at flowering or veraison – there’s evidence that high salt levels might indicate more salt in your grape juice. How much, however, cannot be predicted.

To find out more about salt in winemaking contact Geoff Cowey.

Tracking tropical

What’s the link between tropical aromas in Sauvignon Blanc and the precursors (or compounds) that create them? How do they change or degrade in the vineyard, during transport and in winemaking?

The AWRI’s Aroma Chemistry team has been on a mission to find out. Their discoveries have just been published – a must-read for anyone wanting to know how tropical thiol aromas are created and how precursors change from the vineyard to the winery.

For a summary access the 2009 AWRI Annual Report, or contact the AWRI Library to request the scientific publications:

Synthesis of Wine Thiol Conjugates and Labeled Analogues: Fermentation of the Glutathione Conjugate of 3-Mercaptohexan-1-ol Yields the Corresponding Cysteine Conjugate and Free Thiol. J. Agric. Food Chem. 2010, 58: 13831389.

Analysis of Precursors to Wine Odorant 3-Mercaptohexan-1-ol Using HPLC-MS/MS: Resolution and Quantitation of Diastereomers of 3-S-Cysteinylhexan-1-ol and 3-S-Glutathionylhexan-1-ol. J. Agric. Food Chem. 2010, 58: 13901395.

To find out more contact Dimi Capone, or view the AWRI’s wine thiol precursors webpage.

Green talent

Are you committed to environmentally-friendly wine production, but don’t know where to start or what to do next? The AWRI Commercial Services has a new ‘green team’ of specialists ready to help you.

Karl Forsyth can help you to adopt a range of sustainable practices from more effective wastewater management to calculating your carbon footprint. In today’s environmentally-conscious marketplace, their expertise offers you a competitive edge.

For more information email Karl Forsyth.

London tastes Australia

The AWRI delivered a ‘taster’ of its Advanced Wine Assessment Course in London, in February, in conjunction with Wine Australia’s Annual Trade Tasting, World Class Australia Event.

Hosted by Con Simos, Group Manager, Industry Development and Support at the AWRI, the short course put 26 participants through their paces with two ‘flights’ of Riesling and Shiraz wines. Some wines were repeated to test tasters’ ability to score reliably and consistently.

The day presented a new approach to tasting Australian wine and a snapshot of the AWRI’s well-regarded four-day Advanced Wine Assessment Course. Con Simos went on to showcase the AWRI’s work on flavor including revealing black pepper and eucalyptus aromas as well as other AWRI research programs in Dublin, Ireland.

New Chair

The AWRI has announced that Mr Peter Dawson has been appointed Chair of the AWRI board.

Mr Dawson has played a pivotal role in the development of one of Australia’s largest wine companies Hardy’s – and the industry as a whole. He has served on many industry advisory committees, including the board of the AWRI for the past 10 years.

Peter brings his winemaking credentials as well as stable and visionary stewardship to the board.

Read the AWRI’s media release.