The Australian Wine Research Institute

Ensure your export wine specifications receive a tick of approval
Did you have a difficult or slow malo this vintage? Have you considered co-inoculation?
If you are only measuring DO, you need your head read
Getting a grip on tannin composition and wine astringency
Yeast strain flavour differences keep on keeping on
Join the rush for cheap, fast analysis results
Another 30 graduate from our 30th AWAC tasting boot camp
What is that smell? Call us to find out
Recent publications from AWRI staff members

Ensure your export wine specifications receive a tick of approval

How do you know that the wine you export meets the destination country’s regulations? How confident are you that the processing aids you used are permitted in that country? The AWRI’s website can provide this information.

The AWRI website provides specific information as to what additives and processing aids are permitted in different countries. Plug in one of the 244 additives or processing aids you wish to use, and the database will tell you which countries permit its use. Alternatively, plug in the country you wish to export to (there are 15 countries/markets listed) and the database will tell you which additives or processing aids are permitted. The two databases are called Permitted additives and processing aids for winemaking and wine importing countries and Analytical specifications for the export of Australian wine. Both of these databases were updated this month. The latter contains specifications for 38 countries/markets. While the databases don’t provide a complete list of all the countries to which Australia exports wine, it includes those which have made available their winemaking regulations. Please contact the Health and Regulatory Information Manager for further information.

Did you have a difficult or slow malo this vintage? Have you considered co-inoculation?

Want to put your wine through malo (malolactic fermentation/MLF) but are worried about the risks of spoilage through a prolonged or delayed MLF? There is a solution.

Malolactic fermentation typically occurs after alcoholic fermentation (AF) and can occur spontaneously by the action of indigenous bacteria populations, or can be induced by the winemaker via inoculation with a starter culture. A prolonged or delayed MLF increases the risk of spoilage by other microorganisms, such as Lactobacillus, Pediococcus and Brettanomyces.

A recent trial on the timing of MLF inoculation in Shiraz grape must and wine has shown that a co-inoculation (yeast and bacteria together from the beginning) can reduce the time for MLF by up to 6 weeks. Four different inoculation points were compared (co-inoculation, mid-alcoholic fermentation [AF], at pressing and post-AF). Not only can co-inoculation reduce the overall total time for fermentation (AF + MLF) thus allowing wine to be stabilised earlier, but the wine volatiles profile was distinct from wines produced when bacteria were inoculated late or post-AF.

You can access the paper describing the work via the AWRI library:

Abrahamse, C.E., Bartowsky, E.J. Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition. World Journal of Microbiology and Biotechnology DOI 10.1007/s11274-011-0814-3; 2011.

If you are only measuring DO, you need your head read

We constantly see wines compromised by poor bottling practices. These wines show evidence of loss of fruit character, or have reached their shelf life within six months of bottling due to high oxygen exposure. We can help your bottling operations protect the quality of your vintage ’11 wines.

To ensure your wines are being bottled with the diligence they deserve, the total package oxygen (TPO) levels must be measured. TPO is the combination of both the dissolved oxygen in the wine, plus the oxygen in the headspace. Best practice management of TPO is achieving levels of less than 1.0 mg/L; and less than 2.5 mg/L is regarded as acceptable. In one particular audit we measured TPO at levels approaching 10 mg/L! If you thought sparkling wines aren’t affected, think again!

The AWRI’s Commercial Services has benchmarked over 20 bottling lines across Australia and New Zealand. Whilst oxygen management performance varies greatly, typically 70% of total oxygen is in the headspace. Therefore, just measuring dissolved oxygen has limited value, as it cannot quantify how well the wine was bottled. To have confidence in the quality of your bottling operations, you must measure and manage the TPO.

The AWRI’s Commercial Services is in the process of introducing a TPO accreditation to provide wineries with the confidence that their selected bottling facility has the capability to comply with best practice bottling guidelines. This accreditation will be available to bottlers who can demonstrate acceptable TPO performance and a robust QC regime.

If you require assistance to benchmark the TPO proficiency of your bottling line, or access to our online TPO calculator, please visit our website, or contact the team at AWRI Commercial Services.

Getting a grip on tannin composition and wine astringency

Ever had to peel the inside of your cheeks from your teeth, after a sip of a particularly astringent red wine? Do you know how those puckery tannins will contribute to the mouth-feel of your wine in two, five or ten years? This is something we’re helping winemakers to get a grip on. Tannin concentrations have shown to impact greatly upon red wine astringency, but this doesn’t tell the whole story of why astringency softens as wine ages. Current investigations are delving deeper into the role of tannins in wine, in particular how their composition affects the astringency quality.

Astringency is a complex sensation that involves the binding of tannins to salivary proteins and other surfaces in the mouth. Greater concentrations of tannins have been shown to bind to more proteins and therefore the sensation of astringency is increased. Recent analysis using isothermal titration calorimetry (ITC) has shown that the composition of tannins impacts upon the strength of the protein interaction. This is particularly pronounced when comparing the binding strength of tannins from two year old wines with those from ten year old wines, with older wine tannins interacting comparatively weakly with proteins. These results may also provide some explanation as to why some wines have a harsh and puckering astringency when the tannin concentration is the same as other wines that have a smoother, more velvety astringency.

You can access the paper describing the work via the AWRI library:

McRae, J.M. Falconer, R.J. Kennedy, J.A. Thermodynamics of grape and wine tannin interaction with polyproline: implications for red wine astringency. Journal of Agricultural and Food Chemistry 58 (23) : 12510–12518; 2010.

Yeast strain flavour differences keep on keeping on

You might have read about some of our work on yeasts that bring out different flavour compounds from the grape, over traditional wine yeast, through the fermentation process. But does the effect last? Many winemakers believe that while yeast strains might have a flavour effect in a young wine, any differences disappear after a short time in bottle. This has been disproved.

We conducted a study over two vintages, on Sauvignon Blanc fermented using a number of yeast strains, and cellared for three years. Sensory differences among the wines assessed soon after bottling were still clearly evident after this extended cellar storage. Aroma volatile compositional differences in the young wines, in particular those of the potent ‘tropical’ thiols, were also found to be retained.

You can access the paper describing the work via the AWRI library:

King, E.S., Francis, I.L., Swiegers, J.H., Curtin, C. Yeast Strain-Derived Sensory Differences Are Retained in Sauvignon blanc Wines after Extended Bottle Storage. American Journal of Enology and Viticulture DOI 10.5344/ajev.2011.10079; 2011.

Join the rush for cheap, fast analysis results

Our prices have dropped – see how we do it on our CSI speedy-lab video. Also, watch out for ‘Brett’. Put your mind at ease that no unwanted flavours sneak into your wine and have our experts check it out for you.

• Reduce the costs of export approval
  • We are now offering substantially cheaper analysis for export certification testing (less than half price for some tests). The service includes testing within 24 hours of sample receipt and free delivery of samples to Wine Australia for product approval inspections. See the AWRI website for further information.
• Are you exporting your wine to a market sensitive to Vegans such as India?
  • If so, screening your wine for the presence of dairy products such as the milk protein casein, and egg residue is critical. Cost per sample is $90 (excl. GST) or $160 (excl. GST) for the two analyses combined.
• Watch out – you are now in the Brett Zone!
  • It’s that time of year… primary fermentation is complete but cooler temperatures may mean struggling malo ferments; wines have low SO₂ and are ripe for Brett attack. Wines with low SO₂, high pH and residual sugar can also be at risk. Call us for a bandaid solution.

Another 30 graduate from our 30th AWAC tasting boot camp

Congratulations to another 30 boot camp recruits, who successfully completed our 30th AWAC held at Penfold’s Magill Estate in the last week of June. There were lots of great discussions of wines… what makes a good Shiraz? What’s the future of Chardonnay? What are the best performing alternative varietals? Check out some of the comments @The_AWRI #AWAC twitter account, now up to 600 followers.

As with previous courses, there were a few disappointing international benchmarks. Got any recommendations for us? Con wants to know, email Con at con.simos@awri.com.au. Congratulations to Peter Lehmann Wines… wine of AWAC again was the 2002 Peter Lehmann Reserve Riesling. Thanks also to our passionate guest judges who continue to drive and inspire our future wine judges and industry members who want to improve their palates. Stay tuned to find out who will be this year’s AWAC Dux. The winner will be offered a place as an associate judge at the 2012 Royal Adelaide Wine Show. Interested in attending AWAC 31? Register here.

What is that smell? Call us to find out

Got a smelly wine but you don’t know what it is? Don’t know how to restart that stuck ferment? Received some laccase results, but not sure how to interpret them? Not sure whether there is a higher incidence of cork taint in your wine? Call our winemaking help desk!

Our winemakers Con, Adrian, Geoff and Matt are at the ready to help you find out what is happening with your wine. If we can’t help you out over the phone, you can send samples to us for tasting, analysis and anything else to get to the bottom of the problem for you. We will even write up legal reports if needed for insurance claims or disputes. All this is free for winemakers who pay the Winegrapes and/or Grape Research levies. Find out more about what we offer here, or see our recent eBulletin. Call us on 08 8313 6600 or email winemakingservices@awri.com.au.

Recent publications from AWRI staff members

Research articles and books can be requested from the John Fornachon Memorial Library at infoservices@awri.com.au or phone us on (08) 8313 6600.

Abrahamse, C.E., Bartowsky, E.J. Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition. World Journal of Microbiology and Biotechnology DOI 10.1007/s11274-011-0814-3; 2011.

Curtin, C.D., Bellon, J.R., Bartowsky, E.J., Henschke, P.A., Chambers, P.J., Herderich, M.J., Pretorius, I.S. Harnessing AWRI’s yeast and bacterial research to shape ‘nextgen’ Chardonnay Part 2 : Influence of yeast, nutritional management and malolactic fermentation. Wine and ViticultureJjournal 26 (2) : 15-24; 2011.

King, E.S., Osidacz, P., Curtin, C., Bastion, S.E.P., Francis, I.L. Assessing desirable levels of sensory properties in Sauvignon Blanc wines – consumer preferences and contribution of key aroma compounds. Australian Journal of Grape and Wine Research 17 (2) : 169-180; 2011.

Pocock, K.F., Salazar, F.N., Waters, E.J. The effect of bentonite fining at different stages of white winemaking on protein stability. Australian Journal of Grape and Wine Research 17 (2) : 280-284; 2011.

Ristic, R., Osidacz, P., Pinchbeck, K.A., Hayasaka, Y., Fudge, A.L., Wilkinson, K.L. The effect of winemaking techniques on the intensity of smoke taint in wine. Australian Journal of Grape and Wine Research 17 (2) S29-S40; 2011.

Schmidt, A.A., Dillon, S., Kolouchova, R., Henschke, P.A., Chambers, P.J. Impacts of variations in elemental nutrient concentration of Chardonnay musts on Saccharomyces cerevisiae fermentation kinetics and wine composition. Applied Microbiology and Biotechnology DOI: 10.1007/s00253-011-3197-3; 2011.

Wilkinson, K.L., Ristic, R., Pinchbeck, K.A., Fudge, A.L., Singh, D.P., Pitt, K.M., Downey, M.O., Baldock, G.A., Hayasaka, Y., Parker, M., Herderich, M.J. Comparison of methods for the analysis of smoke related
phenols and their conjugates in grapes and wine. Australian Journal of Grape and Wine Research 17 (2) : S22-S28; 2011.

Winter, G., Van Der Westhuizen, T., Higgins, V.J., Curtin, C., Ugliano, M. Contribution of cysteine and glutathione conjugates to the formation of the volatile thiols 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) during fermentation by Saccharomyces cerevisiae. Australian Journal of Grape and Wine Research 17 (2) : 285-290; 2011.

Disclaimer: The material contained in this publication is comment of a general nature only and is not and nor is it intended to be advice on any specific technical or professional matter. In that the effectiveness or accuracy of any technical or professional advice depends upon the particular circumstances of each case, neither the AWRI nor any individual author accepts any responsibility whatsoever for any acts or omissions resulting from reliance upon the content of any articles. Before acting on the basis of any material contained in this publication, we recommend that you consult appropriate technical/professional advisers.

Challenges with botrytis, laccase and glucans – thanks to a wet harvest
Is that wine yeast up to the task? Choosing the right strain for difficult juices
Your say is important to us
Want to know how transport and harvesting affects tropical aromas in your Savvy?
Hunter Valley and Adelaide Hills – were on our way!
A positive link between wine and improved cognitive function?
Reduced costs of export approval have been well received by many
Jancis Robinson leads international wine delegation to Tasmania
AWRI contributes to new textbook
Recent publications from AWRI staff members

Challenges with botrytis, laccase and glucans – thanks to a wet harvest

If you are dealing with botrytis this vintage, you are not alone. This last month, 1 in 5 calls to our winemaking team have been about botrytis, as winemakers use all their skills this vintage to deal with the effects of processing botrytis affected fruit.

Wines made from grapes affected by Botrytis cinerea may contain laccase, an enzyme which, due to its relative stability in wine, is capable of causing serious oxidative damage. Winemaking strategies for treating botrytis infected fruit in the winery can be found here in our recent eBulletin.

AAlso be aware that botrytis can also produce and release glucans into juice and the resultant wine. Glucans are polysaccharides which are large molecules that can make the wine more difficult to filter. You can test for glucans using the polysaccharides test available on the AWRI website. Commercially available glucanases are available to break down these glucans.

Is that wine yeast up to the task? Choosing the right strain for difficult juices

Due to seasonal variation, vineyard management and differences in grape processing, grape juice composition can vary to the extent that not all yeast strains are capable of thriving in it to make quality wine. Until recently the degree to which grape juice nutrient composition could vary and how that variation affects fermentation performance was not well understood.

Recent work at the AWRI has begun to shed light on these dynamics through a survey of 100 different Chardonnay musts to determine composition and how this composition impacts on performance for different strains of wine yeast. The predominant factor limiting fermentation performance, after YAN, was juice pH. For some yeast strains low juice pH (less than 3.1) and associated low potassium levels can lead to prolonged (sub optimal) fermentation times, high residual sugar and elevated volatile acidity. This work has shown that winemakers working with low pH juices should consider insuring against fermentation difficulties and adverse quality outcomes through judicious choice of yeast strain.

You can access the paper describing the work via the AWRI library:

Schmidt SA, Dillon S, Kolouchova R, Henschke PA, Chambers PJ (2011) Impacts of variations in elemental nutrient concentration of Chardonnay musts on Saccharomyces cerevisiae fermentation kinetics and wine composition. Appl Microbiol Biotechnol DOI: 10.1007/s00253-011-3197-3

Should you require further assistance, please call the AWRI’s Winemaking and Extension Services team on 08 8313 6600 or contact us by email.

Your say is important to us

Recently, youve been given the opportunity to complete some surveys. As the industrys own innovation company, we work for you and what you have to say helps us to deliver to you more of what you really need regardless of your production size. Grape producers have been telling us about their pest and disease management strategies this season; wine industry members have been telling us what they want in our publication, Technical Review, and weve just asked wine producers to tell us about how they use water and wastewater in the production process. Improving your reality matters to us make sure you have your say.

Pest and disease management: Over 160 growers have logged onto http://www.surveymonkey.com/s/2010_11Review and shared their experiences of the 2010/2011 growing season. The information collected about pest and disease management in difficult conditions is going to help regions identify what needs to be done to manage similar conditions in the future. All growers who support their region and complete the survey will be sent the collated results. The survey will be closed on 13 May and personal information is kept confidential. For more information contact Marcel Essling on 08 8313 0370.

Winery wastewater: CSIRO and the AWRI are investigating technologies that may help wineries to improve their business sustainability through improved management of water and wastewater. The first part of our project is to gain a good understanding of how wineries use water and how they manage wastewater. The project is intended to help identify technologies worthy of trials and detailed economic investigations. Click on this link to be taken to the survey: http://www.surveymonkey.com/s/winery_wastewater. For more information contact Karl Forsyth.

Technical Review: So far, weve received comments from over 150 people regarding what they want from Technical Review in the future. Click on this link to access the survey: http://www.surveymonkey.com/s/TR_reader_survey. For more information contact Rae Blair.

Want to know how transport and harvesting affects tropical aromas in your Savvy?

The effects of transport and processing on the compounds which form the tropical aromas in Sauvignon Blanc havent been well understood. Recent studies at the AWRI have revealed some interesting facts.

This study was carried out on a commercial-scale (2.5 tonne replicates) to have direct relevance to the wine industry. One of the most important findings was that a large increase in precursor concentrations was found after transportation of machine-harvested berries. This has implications for the varietal aroma profiles of wines exhibiting tropical and citrus characters.

In this same investigation, replicated experiments were carried out to ascertain the effects of different antioxidant treatments, among other aspects. Learn more about these findings from a scientific paper that has just been published; contact the AWRI library to request a copy.

Effects of Transporting and Processing Sauvignon blanc Grapes on 3-Mercaptohexan-1-ol Precursor Concentrations. J. Agric. Food Chem. 2011, 59 (9), 46594667 .Capone, D.L. and Jeffery, D.W.

For further information, contact Dimitra Capone tel. 08 8313 6689.

Hunter Valley and Adelaide Hills – were on our way!

Our Roadshow team are on their way to the Hunter Valley (18 May) and Langhorne Creek (25 May). Our presentations will address the technical production needs of each region.

The Australian Wine Research Institute will hold two seminars this month to address the issues faced by winegrape producers in the Hunter Valley and Adelaide Hills.

Producers in the Hunter Valley can attend the AWRI presentation on 18 May and those in Langhorne Creek can attend on 25 May.

The seminars are being held in response to a call for more information on how to deal with particular problems on behalf of the local associations in each region.

Amongst the presentations, AWRI Group Manager, Industry Development and Support Con Simos will present at both seminars, focusing on the options available in cold stabilising wine in the Hunter Valley, and management strategies for botrytis and downy mildew in Langhorne Creek.

He says the seminars provide a good opportunity to winemakers and grapegrowers to have their questions answered.

“The regional associations are given the opportunity to say ‘these are the issues and this is what we’d like you to talk about’,” Simos said. “And that’s what we do. It also gives us a great opportunity to interact with local members.”

Those who attend the seminars will also be given an opportunity to discuss other issues not covered in the presentations with the speakers for about one hour.

Grapegrowers, winemakers, suppliers and stakeholders are all encouraged to attend the event in their region.

Both seminars will feature presentations by AWRI viticultural consultant Peter Dry on how vine balance affects yield and quality as well as new AWRI technologies and consumer preferences.

Specific topics to be covered in the Hunter Valley include wine flavour, clones and wild ferments, while the Langhorne Creek seminar will focus on irrigation strategies, disease, health, eucalyptol and bunch rot.

The Hunter Valley seminar will take place from 9am-4pm on Wednesday 18 May at Mercure Resort Hunter Valley Gardens, Chardonnay Room. Cost is $65. Registration is due Monday 9 May.

Contact Melissa Romeyn from Hunter Valley Wine Industry Association on ph. (02) 4991 4533 or at info@winehuntervalley.org.au for more information.

The Langhorne Creek seminar will take place from 9am-4pm on Wednesday 25 May at Langhorne Creek Bowling Club, Sports Oval, Murray Road, Langhorne Creek. Cost is $20. Registration is due Friday 20 May.

Contact Lian Jaensch from Langhorne Creek Grape and Wine Inc. on tel. (08) 8537 3362 or at info@langhornewine.com.au for more information.

A positive link between wine and improved cognitive function?

The AWRI continues its role in coordinating or participating in studies showing the impact of wine consumption on human health. A small pilot study is underway between the AWRI and the Brain Sciences Institute of Swinburne University.

This study is funded by the National Wine Foundation and focuses on whether wine-derived resveratrol has an effect on improving cognitive function (that is, the ability to think, remember and problem solve) and changes in brain blood flow in ageing or older Australians. Dementia is a form of cognitive dysfunction whereby an individual loses the capacity to think, remember and reason due to physical changes in the brain. Dementia is associated with increased disability and an increased need for institutionalised care, especially in an ageing population over 60 years of age. While there are other risk factors for dementia, ageing is by far the most important risk factor. Globally, the population aged 60 years of age is projected to triple by 2050, while the population aged over 80 years is projected to increased by five-fold. At present, there are few options for the treatment of dementia. Interestingly, older Australians generally drink less alcohol at any one drinking session than younger Australians, but they tend to drink alcohol every day. For further information on this study, contact Creina Stockley.

Reduced costs of export approval have been well received by many

“Its heartening to see that AWRI is aware of the hardships faced by Australian Wine Exporters and actually doing something about it.”

Joe Ceravolo – Ceravolo Wines

The AWRI Commercial Services has been working hard over the last 18 months to streamline analytical workflows to do what we can to help the Australian wine industry. Our goal has been to reduce costs and turn around times, while maintaining our strict quality assurance regimes. We are now offering substantially cheaper analyses particularly for export certification testing (less than half price for some tests). See the AWRI website for further information.

Jancis Robinson leads international wine delegation to Tasmania

Interested in hearing the latest developments on cool climate viticulture, oenology and marketing? Like to hear about a major three year research program into improving cool climate Pinot Noir and sparkling wines? Keen to catch up with industry colleagues from around the world?

If so, make sure you have the 8th International Cool Climate Symposium in your diary. Co-presented by Wine Tasmania, The Australian Wine Research Institute and Tasmania Institute of Agricultural Research, this event will be held in Hobart, 31 January to 4 February 2012. Click here for more information.

AWRI contributes to new textbook

A new three volume text book entitled Handbook of enology Principles, practices and recent innovations, has been published recently by AsiaTech Publishers. It features two chapters by AWRI staff members: Creina Stockley and Eveline Bartowsky.

Creina’s 63 page chapter outlines the potential therapeutic effects of wine in moderation and discusses the viticultural and winemaking practices that influence the alcohol and phenolic content of wine – the two key therapeutic components of wine. Eveline’s 38 page chapter focuses on malolactic fermentation.

Recent publications from AWRI staff members

Research articles and books can be requested from the John Fornachon Memorial Library at infoservices@awri.com.au or phone us on (08) 8303 6600.

Bartowsky, E. (2011) Malolactic Fermentation. In Joshi, V.K. (ed) Handbook of Enology: Principles, Practices and Recent Innovations, Volume 2: Principles and Practices: Asiatech Publishers, Inc; New Delhi : 526-563.

Bindon, K.A., Kennedy, J.A. Ripening-Induced Changes in Grape Skin Proanthocyanidins Modify Their Interaction with Cell Walls. Journal of Agricultural and Food Chemistry 59 : 2696-2707; 2011.

Capone, D.L., Jeffery, D.W. Effects of Transporting and Processing Sauvignon blanc Grapes on 3-Mercaptohexan-1-ol Precursor Concentrations. Journal of Agricultural and Food Chemistry doi: 10.1021/jf200119z

Capone, D.L., Sefton, M.A., Jeffery, D.W. Application of a Modified Method for 3-Mercaptohexan-1-ol Determination To Investigate the Relationship between Free Thiol and Related Conjugates in Grape Juice and Wine. Journal of Agricultural and Food Chemistry doi: 10.1021/jf200116q

Cozzolino, D., Cynkar, W., Dambergs, R., Smith, P. Two-dimensional correlation analysis of the effect of temperature on the fingerprint of wines analysed by mass spectrometry electronic nose. Sensors and Actuators B 145 : 628634; 2010.

Curtin, C.D., Bellon, J.R., Bartowsky, E.J., Henschke, P.A., Chambers, P.J., Herderich, M.J., Pretorius, I.S. Harnessing AWRI’s yeast and bacteria research to shape ‘next gen’ Chardonnary Part 1: ‘Wild’ and ‘non-conventional’ yeast. Wine & Viticulture Journal January/February : 15-20; 2011.

Evans, D.E., Goldsmith, M., Dambergs, R., Nischwitz, R. A Comprehensive Revaluation of Small-Scale Congress Mash Protocol Parameters for Determining Extract and Fermentability. Journal of the American Society of Brewing Chemists 69(1) : 13-27; 2011.

Marangon, M., Lucchetta, M., Waters, E.J. Protein stabilisation of white wines using zirconium dioxide enclosed in a metallic cage. Australian Journal of Grape and Wine Research 17 : 2835; 2011.

Stockley, C. (2011) Therapeutic Value of Wine: A Clinical and Scientific Perspective. In Joshi, V.K. (ed) Handbook of Enology: Principles, Practices and Recent Innovations, Volume 1: Introduction to Vine and Wine: Asiatech Publishers, Inc; New Delhi : 146-208.

Torrea, D., Varela, C., Ugliano, M., Ancin-Azpilicueta, C., Francis, I.L., Henschke, P.A. Comparison of inorganic and organic nitrogen supplementation of grape juice Effect on volatile composition and aroma profile of a Chardonnay wine fermented with Saccharomyces cerevisiae yeast. Food Chemistry 127 : 1072-1083; 2011.

Ugliano, M., Kwiatkowski, M., Vidal, S., Capone, D.L., Siebert, T., Dieval, J., Aagaard, O., Waters, E.J. Evolution of 3-Mercaptohexanol, Hydrogen Sulfide, and Methyl Mercaptan during Bottle Storage of Sauvignon blanc Wines. Effect of Glutathione, Copper, Oxygen Exposure, and Closure-Derived Oxygen. Journal of Agricultural and Food Chemistry 59 : 2564-2572; 2011.

Varela, C., Chambers, P.J., Coulter, A., Dry, P.R., Francis, I.L., Gawel, R., Muhlack, R., Henschke, P.A., Stockley, C., Herderich, M.J., Pretorius, I.S. Controlling the Highs and Lows of Alcohol in Wine. Practical Winery and Vineyard Winter : 6-18.

Vincenzi, S., Marangon, M., Tolin, S., Curioni, A. Protein evolution during the early stages of white winemaking and its relations with wine stability. Australian Journal of Grape and Wine Research 17 : 20-27; 2011.

Disclaimer: The material contained in this publication is comment of a general nature only and is not and nor is it intended to be advice on any specific technical or professional matter. In that the effectiveness or accuracy of any technical or professional advice depends upon the particular circumstances of each case, neither the AWRI nor any individual author accepts any responsibility whatsoever for any acts or omissions resulting from reliance upon the content of any articles. Before acting on the basis of any material contained in this publication, we recommend that you consult appropriate technical/professional advisers.