The Australian Wine Research Institute

Manganese levels in wine
Mapping pepper
Beating Brett
Secrets of solids
Shiraz symposium
Riverland Roadshow breaks record
Allergen assistance available
Information packs help you find what you need
Time to catch up on webinars?
Recent literature

Manganese levels in wine

As has been widely reported, the Chinese government recently enforced mandatory upper limits on copper (1 mg/L), iron (8 mg/L) and manganese (2 mg/L) in wine. While the typical levels and impacts of iron and copper are well established, manganese levels in wine are less well understood, although at the levels analysed, are not believed to pose any health or quality issues. Since the introduction of the limit, the AWRI has analysed the manganese levels of more than 800 wines and some important trends in the data have been observed.

Firstly, the distribution of results was consistent for all wines irrespective of origin. This suggests that manganese levels in wine are common worldwide. Secondly, a significant number of wines exceeded the 2 mg/L limit, with higher manganese levels seen in red wine than in white wine. This may be due to the extraction process during the fermentation of red wine releasing more manganese from the grape skins and flesh. No significant differences were seen among varieties of red and white grapes; however, there does appear to be a vintage-to-vintage variation, with the median values for the 2011 season being significantly lower than those for 2009 and 2013. The median values for 2010 and 2012 fell between these two groups.

Manganese occurs naturally in soils and grapes; however one published study from Sicily (La Pera et. al. 2008) found that certain manganese-based fungicide treatments could significantly increase the concentration of manganese in wine. It should, however, be noted that the AWRI has analysed wines which exceeded the limit which have not received any such fungicide treatments. The impacts of manganese-containing viticultural products are still to be confirmed in the Australian context.

The AWRI has also tested a number of wine fining treatments for their effects on manganese concentration. To date, none tested has shown a satisfactory impact on reducing the manganese concentration of wine. Work is continuing to assess a range of other possible processing and fining options. In the mean time, the current recommendation is that all wines destined for export to China should be tested for copper, iron and manganese at one of the laboratories offering this service.

For more information, contact Dr Eric Wilkes, Group Manager Commercial Services, eric.wilkes@awri.com.au or 08 8313 6600.

Reference

La Pera, L., Dugo, G., Rando, R., Di Bella, G., Maisano, R., Salvo, F. (2008). Statistical study of the influence of fungicide treatments (mancozeb, zoxamide and copper oxychloride) on heavy metal concentrations in Sicilian red wine. Food Additives & Contaminants: Part A, 25(3), 302-313.

Mapping pepper

For the first time, the distribution of the ‘pepper’ compound rotundone has been mapped in a Shiraz vineyard. Results recently published in the Australian Journal of Grape and Wine Research highlighted a surprisingly wide concentration range of rotundone in grapes across the block. The study showed clearly the large spatial variability of the compound and that it is linked to differences in soil characteristics and topography. The topographical variation pointed towards temperature and/or solar radiation effects being involved, rather than vine vigour.

The rotundone level was measured in grape berry samples from 177 vines within a 6.1 ha block in the Grampians, a region known for producing wines of ‘peppery’ character. The results were mapped and overlaid with other map layers showing variation in soils, topography and vine vigour.

This is believed to be the first study of within-vineyard spatial variability of a key grape-derived flavour compound. It highlights the potential opportunity to use selective harvesting or targeted viticultural manipulation as a means of influencing wine style – in this case the ‘pepperiness’ of Shiraz. The study was conducted with Dr Rob Bramley of CSIRO Ecosystem Sciences and the late Nathan Scarlett of Rathbone Wine Group.

A copy of the article can be ordered online here or by contacting infoservices@awri.com.au.

Beating Brett

Several new resources on Brettanomyces have just been added to the AWRI website, bringing together knowledge from researchers and the AWRI helpdesk team. First up is a new fact sheet which provides up-to-date advice on controlling Brett in the winery. Next there’s a comprehensive list of frequently asked questions about Brett – if you can think of a question that hasn’t been covered, get in touch and we’ll add it to the list. Finally, there’s a new information pack of published papers and other resources relevant to Brett spoilage. Wines are most vulnerable to Brett growth around the end of malolactic fermentation before SO₂ is added, so stay vigilant!

Secrets of solids

Fermenting white juices containing high levels of grape solids can result in increased hydrogen sulfide production during primary fermentation. However, excessively clarifying juices may result in attenuated or stuck primary or malolactic fermentations resulting in elevated levels of volatile acidity. Well so says Winemaking 101.

While there is a lot to be said for Winemaking 101, previous work by the AWRI has revealed that fermenting on grape solids also results in significantly more polysaccharides in white wines – more than extensive skin contact, using pressings, and even more than (what many may consider a radical practice of) partially fermenting white juice on skins. Higher levels of polysaccharides are thought to positively contribute to white wine mouth-feel, and to enhance both protein and cold stability resulting in less bentonite fining and lower refrigeration costs.

While juices will naturally clarify under the action of gravity given time, vintage logistics dictate that the settling process be achieved as quickly as possible (“We have plenty of time – it’s vintage” is a phrase never said). Typically faster clarification is achieved by adding pectolytic enzymes, which within minutes, ‘mulch down’ the juice polysaccharides that inhibit settling. Alternatively, settling can be sped up by adding bentonite as its charged surface helps to agglomerate grape solids into heavy particles that precipitate more easily.

In a new project, the AWRI is investigating the effect of different types of juice clarification (natural settling, enzyme- and bentonite-assisted settling) on the macromolecular composition of white wine. The effects of the method of clarification and the time taken to achieve various levels of clarity on the polysaccharide, protein and phenolic composition are being investigated now. Industry partners are being sought to participate in a winery-scale project in 2015.

For more information or to express interest in being involved in the 2015 trial, please contact Richard Gawel, richard.gawel@awri.com.au or 08 8313 6600.

Shiraz symposium

A one-day Symposium exploring the latest developments and innovations in cool climate Shiraz production will be presented by the AWRI and Wine Victoria in Melbourne on 11 June. The Symposium will include insights into international Shiraz production, technical presentations on flavour characters, case studies on Shiraz winemaking and a tasting of memorable cooler climate Shiraz wine styles.

The full program for the day can be accessed here. Bookings are essential, and can be made using the online registration and payment form.

When:	Wednesday, 11 June, 2014, 9.20 am – 4.30 pm
Where:	The William Angliss Institute, Auditorium, 555 La Trobe Street, Melbourne
Registration cost:	$99.00 including GST

For more information about the Symposium, please contact Mark Krstic on 0437 325 438 or mark.krstic@awri.com.au.

Riverland Roadshow breaks record

A record-breaking crowd of 81 people attended the AWRI’s Roadshow seminar in Renmark last week. AWRI Researchers were joined by Dr Mike McCarthy from SARDI and Dr. Jason Smith from NGWIC in presenting topics covering irrigation, clones, grapevine nutrition, post-harvest management and managing phenolics quality. A lively interactive session was a highlight of the day. The next region to be visited by the Roadshow team is Queensland – so the challenge is now on to the Queensland industry to set a new record!

Allergen assistance available

Allergies to wine are extremely rare; however certain countries including Australia include allergen warnings on the label of wines and wine products. It’s therefore important for wine producers to understand which processing aids may result in allergen residues as well as the rules on allergen labelling for different countries. The AWRI’s Wine allergen portal provides a comprehensive and up-to-date collection of online resources related to allergens in wine for consumers and producers.

AWRI Commercial Services also provides an allergen testing service.

If you have any questions about allergens in wine, please contact Creina Stockley on 08 8313 6600 or creina.stockley@awri.com.au.

Information packs help you find what you need

Are you looking for the latest grape and wine information? A new page on the AWRI website lists information packs with up-to-date resources on a range of useful topics. Each pack contains reference lists and fact sheets on the particular topic. Articles can be easily ordered online from the AWRI Library. Topics include: heat and cold stability, making lower alcohol wines, emerging varieties and measures of quality from vineyard to winery.

Time to catch up on webinars?

Since 2012, the AWRI has hosted more than 35 webinars on topics including: canopy management, hybrid yeast, alternatives to bentonite, rootstocks, oxygen management during winemaking and dealing with frost. If you missed a webinar when it was broadcast, you can still watch it at a time of your choice by accessing the recordings on the AWRI website. Recordings of the 2012 webinars and 2013 webinars are available. You will need to enter your name and email address for access, and you may need to download a small piece of software called a codec to allow the recordings to play on your computer. If you have any difficulties accessing the recordings, please contact Michael Downie on 08 8313 6600 or infoservices@awri.com.au.

Recent literature

The John Fornachon Memorial Library at the AWRI delivers journal articles and loans books to Australian grapegrowers and winemakers. Publications can be searched and requested via the Library catalogue – or you can email the AWRI with your request. A list of recent AWRI publications follows.

• To order AWRI staff publications and articles from Technical Review please contact the Library.
• Articles and books on specific topics can be searched for and ordered via the Library catalogue
• To request a Literature search on a specific topic contact the Library via email or telephone (08) 8313 6600.

Recent AWRI staff publications

1597 Mayr, C.M., Parker, M., Baldock, G.A., Black, C.A., Pardon, K.H., Williamson, P.O., Herderich, M.J., Francis, I.L. Determination of the importance of in-mouth release of volatile phenol glycoconjugates to the flavor of smoke-tainted wines. J. Agric. Food Chem. 62 (11): 2327-2336; 2014.

1598 Scrimgeour, N., Wilkes, E. Closure trials show volatile sulfur compound formation can still cause a stink. Aust. N.Z. Grapegrower Winemaker (602): 62, 64-67; 2014.

1599 Coulter, A. Ask the AWRI: Can ‘Brett’ affect white wines? Aust. N.Z. Grapegrower Winemaker (602): p.54; 2014.

1600 Dry, P. Souzao. Wine Vitic. J. 28 (2): p. 60; 2014.

1601 Krstic, M., Barlow, S. Vintage 2030 and beyond: Producing quality wines in warmer times. Wine Vitic. J. 28 (2): 52-57; 2014.

1602 Smith, P., Bindon, K., McRae, J., Kassara, S., Johnson, D. Tannin: impacts and opportunities along the value chain. Wine Vitic. J. 28 (2): 38-41; 2014.

1603 Cordente, A.G., Cordero-Bueso, G., Pretorius, I.S., Curtin, C.D. Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation. Fems Yeast Res. 13 (1): 62-73; 2014.

1604 Uberti, F., Danzi, R., Stockley, C., Peñas, E. Ballabio, C., Di Lorenzo, C., Tarantino, C., Restani, P. Immunochemical investigation of allergenic residues in experimental and commercially-available wines fined with egg white proteins. Food Chem. 159: 343-352; 2014.

1605 Capone, D.L., Herderich, M.J., Pardon, K.H., Hayasaka, Y., Cordente, A.G., Grant-Preece, P.A., Sefton, M.A., Elsey, G.M., Jeffery, D.W. Formation of varietal thiol aroma compounds in wine: Synthetic and analytical studies of grape and wine thiol conjugates. In Hofmann, T., Meyerhof, W., Schieberle, P. (eds) Advances and Challenges in Flavor Chemistry and Biology: Proceedings of 9^th Wartburg Symposium on Flavour Chemistry and Biology, Eisnach, Germany Deutsche Forschungsanstalt für Lebensmittelchemie: Freising, Germany 242-248; 2011.

1606 Mateo, E., Torija, M.J., Mas, A., Bartowsky, E.J. Acetic acid bacteria isolated from grapes of South Australian vineyards. Int. J. Food Microbiol. 178: 98-106; 2014.

1608 Taylor, A., Day, M.P., Hill, S., Marshall, J., Patriarca, M., White, M. Atomic spectrometry update: Review of advances in the analysis of clinical and biological materials, foods and beverages. Journal of Analytical Atomic Spectrometry 29 (3): 386-426; 2014.

1609 Borneman, A.R., Zeppel, R., Chambers, P.J., Curtin, C.D. Insights into the Dekkera bruxellensis genomic landscape: Comparative genomics reveals variations in ploidy and nutrient utilisation potential amongst wine isolates. PLoS Genetics 10 (2): e1004161; 2014.

1610 Scarlett, N.J., Bramley, R.G.V., Siebert, T.E. Within-vineyard variation in the ‘pepper’ compound rotundone is spatially structured and related to variation in the land underlying the vineyard. Australian Journal of Grape and Wine Research DOI: 10.1111/ajgw.12075: 9 p.; 2014.

1611 Mayr, C., Geue, J., Holt, H., Pearson, W., Francis, I.L. Characterization of the key aroma compounds in Shiraz wine by quantitation, aroma reconstitution, and omission studies. J. Agric. Food Chem. DOI: 10.1021/jf405731v: 36 p.; 2014.

1612 Dry, P. Ask the AWRI: Bunches with ripe and unripe berries. Aust. N.Z. Grapegrower Winemaker (603): p.49; 2014.

1613 Essling, M. The role of potassium in grapevine function. Aust. N.Z. Grapegrower Winemaker (603): p.74; 2014.

1614 Contreras, A., Henschke, P., Chambers, P., Curtin, C., Varela, C. New yeast approach is aiming to produce a lower alcohol wine. Aust. N.Z. Grapegrower Winemaker (603): 82-83; 2014.

1615 Kutyna, D.R., Cordente, A.G., Varela, C. Genetic engineering of industrial Saccharomyces cerevisiae strains using a selection/counter-selection approach. Mapelli, V. (ed.) Yeast metabolic engineering: methods and protocols. Totowa, N.J.: Humana Press. Chapter 9: 157-168; 2014.

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.

Important regulatory changes for wine exported to China
Vintage 2014 – Half time report
Significant interest in low alcohol yeast
Closure benchmarking trial set to sparkle
Which paints cause taints?
Did you miss a webinar?
Two new fact sheets shed light on tannin measurement
Louisa Rose to chair the AWRI Board
Australian Wine Industry Technical Conference update
2006-2013 Final Report available online
Recent literature

Important regulatory changes for wine exported to China

On 27 February, Wine Australia released a warning to wine exporters regarding the increased scrutiny of manganese, iron and copper levels in wine by Chinese authorities. Maximum regulatory levels now being imposed by Chinese authorities are 2 mg/L for manganese, 1 mg/L for copper and 8 mg/L for iron. It is therefore recommended that all wine intended for export to China should undergo analysis to confirm that it complies with these limits. Excessive levels of copper and iron in wine have been shown to decrease the shelf life of wines and in some cases promote the formation of unpleasant sulfides, while manganese has a limited impact on wine chemistry. For all three metals there are no health concerns at these levels.

Analysis of these metals is available through reputable laboratories including AWRI Commercial Services For more information about manganese and other metals please contact winemakingservices@awri.com.au.

Vintage 2014 – Half time report

Vintage is well underway in most regions now, and so far it has been one influenced by extreme weather conditions, especially in south-eastern Australia. Heatwaves and record breaking daytime temperatures, followed by 100 mm of rain in some locations, have been experienced in the first part of the 2014 vintage. Smoke taint has been by far the biggest concern this vintage and represents nearly 25% of the vintage-related calls received by the AWRI’s helpdesk so far.

As reported previously (eNews November 2013) most wine-grape varieties are highly sensitive to smoke taint from seven days post-veraison to harvest. This means if a vineyard has been exposed to smoke sometime after the point when the berries are pea size, the recommendation is to sample the vineyard two weeks prior to the harvest date and conduct a small-lot fermentation. The wine resulting from this fermentation can be subjected to sensory assessment and chemical analysis (for both volatile phenols and their glycoside precursors) in order to gauge the potential risk of any smoke taint that might arise from the smoke exposure. The AWRI’s website provides links to a range of resources on smoke taint as well as further information about the susceptibility of grape varieties. Results from a limited number of small-lot ferment samples analysed this vintage have shown that when volatile phenol results are low, glycoside precursor levels can still be above those seen in a previous study of baseline concentrations. It is therefore recommended that all analytical data (i.e. volatile phenols and their glycoside precursors) be compared with sensory results to give a true picture of any effects due to smoke.

At the other end of the weather spectrum, there have been many discussions between vineyard owners and winemakers regarding the effects of the heavy rain that hit south-eastern Australia in the second week of February. If berries have split, this increases the potential for disease, including Botrytis cinerea. Wines made from Botrytis-affected grapes may contain laccase, an enzyme which is capable of causing serious oxidative damage. Testing for laccase is strongly advised. More information on managing Botrytis-affected fruit can be found in this fact sheet.

Stuck fermentations (both primary and secondary) can be a winemaker’s worst nightmare, with a number of flow-on effects including holding up fermentation vessels and compromising wine quality. In 2013 the AWRI’s helpdesk received a large volume of calls relating to these types of problems. This eBulletin is worth revisiting for its tips on how to prevent fermentation problems this vintage.

Significant interest in low alcohol yeast

Since the AWRI’s publication of a peer-reviewed article on the capacity of Metschnikowia pulcherrima AWRI1149 to produce wines with lower alcohol when used in sequential inoculation with a wine yeast strain, there has been considerable industry interest in accessing AWRI1149.

To the best of the AWRI’s knowledge, this yeast strain is not currently commercially available; however, several companies have expressed interest in commercialising it. The AWRI will be conducting its own pilot-scale trial with AWRI1149 this vintage.

One of the interesting findings of the research was that of the five strains of M. pulcherrima tested, only one was found suitable to produce lower alcohol wines via sequential inoculation. Performance in sequential inoculations was highly strain dependent. Winemakers should therefore not assume that if one strain of M. pulcherrima is commercially available that it will necessarily share the properties of AWRI1149.

To request a copy of the peer-reviewed article, please contact the AWRI’s library on infoservices@awri.com.au. For more information on sequential inoculation or to express interest in being involved in industry trials, please contact Paul Chambers on 08 8313 6600 or paul.chambers@awri.com.au.

Closure benchmarking trial set to sparkle

In 2014, AWRI Commercial Services will be conducting the world’s first large-scale benchmarking trial for sparkling wine closures. The trial will evaluate the impact of a broad range of different closure technologies on a premium bottle-fermented Chardonnay Pinot Noir, and will run for an initial 24-month period.

The objectives of the trial are to:
• Quantify key physical chemical and sensory impacts from each closure
• Compare the shelf-life of sparkling wine under different closures.

A group of local sparkling wine producers and a number of international closure suppliers have committed to the trial, which is expected to start in the next two months. The trial is structured to enable cost effective access to relevant results and there are multiple options available to fit producers’ technical requirements and budgets.

With the growing consumer interest in sparkling wine and the ever increasing number of closure choices available, there has never been a more important time for producers to be confident in the performance and consistency of their sparkling wine closure.

The AWRI has years of evidence demonstrating how closure selection affects the shelf-life and stylistic development of still wines, but currently there is very limited information available for sparkling wines. This trial will provide a rigorous independent assessment of closure performance to give wine producers and closure suppliers the information they need to make informed decisions for their products.

A targeted industry survey has identified the top six closures that are of most interest for Australian sparkling wine producers. These six closures form the core part of the trial and include traditional, technical and alternative closure technologies. Additional closures are also being sponsored for inclusion by closure suppliers.

The analytical testing schedule includes basic wine attributes, colour development, sulfur-containing compounds, carbon dioxide (CO₂) retention, oxygen transmission rate (OTR), physical integrity and descriptive sensory analysis.

In addition, the AWRI intends to hold a number of tasting workshops in selected regions to showcase the wine’s development under the different closures. This will give small and medium wine producers the opportunity to experience the sensory impact of closure choice firsthand and will provide an overview of the trends seen throughout the trial.

If you wish to be involved in this trial or would like further information, please contact Neil Scrimgeour on 08 8313 6600 or neil.scrimgeour@awri.com.au.

Which paints cause taints?

Every vintage, the AWRI sees some wines that have been tainted by aromatic hydrocarbons from paints used on grape bins or other winery equipment. Appropriate choice of paint and sufficient curing time can go a long way towards preventing unwanted taints.

Grape bins today are typically made out of stainless-steel or high density polyethylene which can be used without the need for painting or pre-treating before use. However, bins made from non-food grade material or base steel need to be painted periodically, so they can be used in the wine industry. But which paints should you use? The paint must be suitable for contact with food, and recommended for grape bins. The main options are single pack and two pack epoxy; and both have advantages and disadvantages. It is recommended that your choice be guided by consultation with your paint supplier.

Which paints cause taints? If not applied correctly or not given enough time to dry and cure, any paint can cause a taint. Having said that, if the manufacturer’s instructions are followed for application, drying and curing time, the likelihood of a taint is significantly reduced. It is recommended that 7 to 12 days be allowed for single pack and two pack epoxy paints to fully dry and cure before use.
For more information about wine taints, please contact winemakingservices@awri.com.au.

Did you miss a webinar?

Since 2012, the AWRI has hosted more than 35 webinars on topics including: canopy management, hybrid yeast, alternatives to bentonite, rootstocks, oxygen management during winemaking and dealing with frost. If you missed a webinar when it was broadcast, you can still watch it at a time of your choice by accessing the recordings on the AWRI website. Recordings of the 2012 webinars and 2013 webinars are available. You will need to enter your name and email address for access, and you may need to download a small piece of software called a codec to allow the recordings to play on your computer. If you have any difficulties accessing the recordings, please contact Michael Downie on 08 8313 6600 or infoservices@awri.com.au.

Two new fact sheets shed light on tannin measurement

Tannin and colour measurement in grapes and wine can be challenging – and around the world different analytical methods are used. Two new fact sheets (one on grape analysis and one on wine analysis) have recently been added to the AWRI website, explaining how results from the WineCloud^TM can be compared to those from other common methods.

There are a number of different methods available for the analysis of colour (anthocyanins) and phenolics in grapes. These methods all use spectroscopic techniques to measure the total anthocyanin and polyphenol content of grape homogenates. However, the extraction media used (pH and ethanol concentration) and the homogenisation processes are different for each method and therefore the extraction efficiency in each case will be different. The preparation method appears to influence all published methods for the determination of colour and phenolics in grapes.

The WineCloud^TM incorporates the AWRI’s standard method (Iland et al. 2004) for the measurement of grape anthocyanins and phenolics, and a predictive algorithm based on the methyl cellulose precipitation (MCP) method developed by the AWRI (Dambergs et al. 2012) for the measurement of tannin.

Those wishing to develop a better understanding of the anthocyanin, phenolic and tannin levels in their grapes should be aware of the impact that homogenisation method and extraction medium can have in extracting these components from the grape homogenate.
For more information on tannin measurement for grapes and wine, please contact Neil Scrimgeour on 08 8313 6600 or neil.scrimgeour@awri.com.au.

References

Dambergs, R.G., Mercurio, M.D., Kassara, S., Cozzolino, D., Smith, P.A. Rapid measurement of methyl cellulose precipitable tannins using ultraviolet spectroscopy with chemometrics – application to red wine and inter-laboratory calibration transfer. Appl. Spectrosc. 66 (6): 656-664; 2012.

Iland, P., Bruer, N.; Wilkes, E., Edward, G. Anthocyanins (colour) and total phenolics of grape berries. Chemical Analysis of Grapes and Wine: Techniques and Concepts, 1st ed.; Winetitles: Broadview, Australia, 2004; pp 44.

Louisa Rose to chair the AWRI Board

Yalumba and Hill-Smith Family Vineyards Chief Winemaker Louisa Rose has been elected the fifteenth Chair of the Board of the Australian Wine Research Institute (AWRI).

Known for her work in pioneering Viognier in Australia, Louisa Rose has more than 20 years of wine industry experience and has been Chief Winemaker at Yalumba and Hill-Smith Family Vineyards since 2006. Louisa has been highly awarded for her winemaking including being named Barossa Winemaker of the Year in 1999, International Woman in Wine by the International Wine and Spirit Competition in 2004 and Winemaker of the Year by Gourmet Traveller Wine Magazine in 2008. Louisa is an experienced wine show judge, and has chaired both Perth and Hobart wine shows. She is co-chair of the South Australian Wine Industry Council and a member of the South Australian Agribusiness council.

Louisa holds a Bachelor of Science in Physics and a Bachelor of Applied Science in Oenology. During her time at Yalumba she has been a supportive industry partner for a number of AWRI research projects, particularly in the area of non-conventional yeast.

Louisa takes over from Peter Dawson who has served as a Board member since 2002 and as Chair since 2010. The AWRI Board thanked Peter for his long-standing support of the AWRI and his exceptional contributions as Board member and Chair. A farewell function was held by the Board for Peter in December 2013.

Australian Wine Industry Technical Conference update

The AWITC recently announced that the16^th Australian Wine Industry Technical Conference & Trade Exhibition 2016 will be held at the Adelaide Convention Centre, from 23 to 28 July 2016.

The 16^th AWITC & TE 2016 will include plenary sessions, workshops, posters, social functions and an extensive trade exhibition.

Significant support for the event has recently been confirmed from two key partners – Primary Industry and Regions SA (PIRSA) and the Adelaide Convention Centre (in association with their industry partners the South Australian Tourism Commission and the Adelaide Convention Bureau).

For more information about the 2016 event, please contact Kate Beames, Conference Manager, on 08 8313 6600 or kate.beames@awitc.com.au.

2006-2013 Final Report available online

At the conclusion of the AWRI’s 2006-2013 investment agreement with the GWRDC, AWRI staff prepared a detailed report of the key outcomes from that 7-year period. This report is now available from the AWRI website.

The report is divided into 13 streams plus an Impact Summary and includes a full list of publications from the investment period.
The outcomes achieved for industry during the period reflect the success of the investment model that was in place – one that combined long-term stability with short-term adaptability and allowed the AWRI to pursue medium-term research and development projects while responding to changing industry conditions.

Recent literature

John Fornachon Memorial Library at the AWRI delivers journal articles and loans books to Australian grapegrowers and winemakers. Books can be searched and requested via the Library catalogue – or you can email the Library with your request. A list of recent AWRI publications follows.

• To order AWRI staff publications and articles from Technical Review please contact the Library
• Articles and books on specific topics can be searched for and ordered via the Library catalogue
• To request a Literature search on a specific topic contact the Library via email or telephone 08 8313 6600.

Recent AWRI staff publications

1583 Contreras, A., Hidalgo, C., Henschke, P.A., Chambers, P.J., Curtin, C., Varela, C. Evaluation of non-Saccharomyces yeast for the reduction of alcohol content in wine. Appl. Environ. Microbiol. doi:10.1128/AEM.03780-13; 2013.

1584 Viviers, M.Z., Smith, M.E., Wilkes, E., Smith, P.A. Effects of metals on the evolution of volatile sulfur compounds in wine during bottle storage. Aust. N.Z. Grapegrower Winemaker (600): 49-51; 2014.

1585 Wilkes, E. You’ve got to be a hot shot to hit the moving target of cold stability. Aust. N.Z. Grapegrower Winemaker (600): 43-46; 2014.

1586 Cowey, G. Ask the AWRI: Top tips for a successful yeast culture. Aust. N.Z. Grapegrower Winemaker (600): p. 42; 2014.

1587 Bindon, K.A., Madani, S.H., Pendleton, P., Smith, P.A., Kennedy, J.A. Factors affecting skin tannin extractability in ripening grapes. J. Agric. Food Chem. doi.org/10.1021/jf4050606: 12 p.; 2014.

1588 Dry, P. Malvasia istriana. Wine Viti. J. 29 (1): p. 53; 2014.

1589 Viviers, M., Smith, M., Wilkes, E., Smith, P., Johnson, D. The role of trace metals in wine ‘reduction’. Wine Viti. J. 29 (1): 38-40; 2014.

1590 Francis, L. Des études multidisciplinaires à l’Australian Wine Research Institute. Revue des Oenologues et des Techniques Vitivinicoles et Oenologiques (149 Supp.): p. 9; 2013.

1591 Geffroy, O., Dufourcq, T. Carcenac, D., Siebert, T., Herderich, M. Nouvelles acquisitions sur le caractère poivré. Des vins rouges de Duras de l’AOP Gaillac. Revue des Oenologues et des Techniques Vitivinicoles et Oenologiques (149 Supp.): 49-51; 2013.

1592 Bartowsky, E., Costello, P., Krieger-Weber, S., Silvano, A., Dumont, A., Francis, L., Travis, B. Au-delà de la fermentation malolactique. Évaluation et caracterisation de l’impact sensorial des bactéries oenologiques sur le caractère fruité des vins rouges. Revue des Oenologues et des Techniques Vitivinicoles et Oenologiques (149 Supp.): 61-65; 2013.

1593 Essling, M. Ask the AWRI: Canopy damage from herbicides. Aust. N.Z. Grapegrower Winemaker (601): p. 32; 2014.

1594 Dry, P. Terroir and the topic of wine typicity. Aust. N.Z. Grapegrower Winemaker (601): p. 40; 2014.

1595 McRae, J., Smith, P. Seal the deal on pH, red wine colour and tannin during bottle ageing. Aust. N.Z. Grapegrower Winemaker (601): 51-54; 2014.

1596 Gawel, R., Schulkin, A., Smith, P.A., Waters, E.J. Taste and textural characters of mixtures of caftaric acid and Grape Reaction Product in model wine. Aust. J. Grape Wine Res. 20 (1): 25-30; 2014.

Pre-vintage reminder on Brett avoidance and control
Making the most of your smart phone or tablet in the vineyard
Refrigeration and wastewater workshops
Encouraging Chinese consumers to choose Australian wines
Nobel Prize winner to join the AWRI Board
Partnerships bring new opportunities
Well-deserved recognition for Mardi Longbottom
AWRI Annual Report available online
Recent literature

Pre-vintage reminder on Brett avoidance and control

With another vintage just around the corner (or already commenced in some of the warmer regions) it is a good time to brush up on the winemaking practices that can help to avoid Brettanomyces spoilage. As harvest is such a busy time of year and often involves new staff members, simple procedures can be overlooked in the rush. The AWRI has put together a list of tips that will help you stay on top of Brett prevention.

1. Sulfur dioxide is Brett’s worst enemy and the sooner you can make additions to harvested fruit, the better. Machine harvested fruit is particularly in need of protection, so consider a 100 g/tonne addition of potassium metabisulfite (PMS) to bins.
2. High pH favours Brett growth so if you know that your must is likely to have high pH, make an acid addition at the crusher. As soon as you know the pH of the homogenised must (make sure the sample is representative) adjust the pH if necessary. Red musts should be adjusted to below pH 3.4 whilst aiming for a titratable acidity (TA) of about 7.5 – 8.0 g/L. However, if the desirable TA cannot be achieved, then the must should be adjusted to pH 3.4 or below regardless of the amount of tartaric acid required to do so. Note that a large amount of the acid added will drop out later as potassium bitartrate (KHT), resulting in a decrease in the TA in the finished wine.
3. During fermentation, potassium ions are leached from grape skins, resulting in a pH rise. It is recommended, therefore, that pH be measured during fermentation on skins and additions should be made to maintain the pH in the range 3.4 – 3.5. If the pH of the resulting wine is greater than 3.6, then precipitation of KHT will result in an increase in pH, which is undesirable because high pH favours Brett growth. If the wine pH is less than 3.6, then precipitation of KHT results in a decrease in pH, which is more desirable.
4. Ensure that all winery and vineyard equipment such as grape bins are sanitised regularly and that wine hoses are drained of cleaning water. Water combined with sugar is an ideal breeding ground for a host of spoilage microorganisms.
5. Ensure red ferments are healthy with a sufficient yeast cell population to complete ferment; Brett growth is highly favoured in the presence of residual sugar. Keep ferments warm towards the end, particularly once off skins, and check residual sugar levels, especially if going straight to barrel.
6. Barrels can be a major source of contamination; if you have any suspect barrels you can get them tested through the AWRI’s Commercial Services https://www.awri.com.au/commercial_services/analytical_services/analyses/4ep-4eg/.
7. Whilst various forms of barrel cleaning are available, if you have a history of Brettanomyces contamination the recommended treatment is to fill barrels with hot water at 85°C for fifteen minutes or until the exterior of the barrel is hot to touch. Take the time to check that your hot water thermostat is accurate pre-vintage and make sure staff are aware of the OH&S issues associated with working with hot water.
8. Malolactic fermentation (MLF) is a critical period for avoiding Brett contamination and growth. Ensure that pH levels never get higher than 3.6 by adjusting early (see points 2 and 3), keep barrels topped and ensure that barrels are sulfured as soon as you know MLF is complete. A large SO₂ addition is better than multiple small ones, so consider an 80 mg/L addition post MLF.
9. If you take one action this vintage to control Brett, do this: add a column for molecular SO₂ (MSO₂) to your lab analysis sheet. Molecular sulfur dioxide is determined by the relationship between pH and free SO₂, and it is recommended to maintain levels above 0.6 mg/L. To calculate MSO₂, you can use the AWRI’s online calculator https://www.awri.com.au/industry_support/winemaking_resources/calculators/molecular-sulfur-dioxide/ or the AWRI winemaking calculators app https://www.awri.com.au/industry_support/winemaking_resources/winemaking-calculators-app/.

Making the most of your smart phone or tablet in the vineyard

Smart phones and tablets have rapidly transformed the way in which data and information can be obtained, collected and stored. With the increasing access that grapegrowers and viticulturists have to these tools, there are substantial resources and digital technologies available to increase productivity and efficiency and improve vineyard management.

The AWRI has developed a practical, hands-on workshop to be delivered during 2014 to assist grapegrowers in integrating smart phones and tablets into the management of their businesses. The workshop will be launched in the Barossa Valley and McLaren Vale next week.

Topics covered will include internet access, different technology platforms, data plans and coverage, tools to assist in working remotely, accessories, mobile security, apps relevant to vineyard management and viticultural businesses, and social media.

Dates and venues for the two launch workshops are :
15 January 2014, 9am-1pm – Barossa Weintal Resort, Tanunda SA
16 January 2014, 9am-1pm – McLaren Vale Visitor Centre, McLaren Vale SA

To book a place, please contact Paula Edwards on 08 8323 0056 or paula.edwards@winegrapes.com.au.

For more information, or if you think the growers in your region could benefit from attending this workshop, please contact Peter Godden on peter.godden@awri.com.au or 08 8313 6600.

Refrigeration and wastewater workshops

AWRI Commercial Services engineers are running two winery operations workshops in WA next week. The one-day workshops will focus on winery refrigeration and wastewater – key areas for reducing costs and improving environmental impact. The workshops will take place at the following dates and locations:

14 January, 9am-4.30pm – Faber Vineyard, Baskerville WA
16 January, 9am – 4.30pm – Cape Mentelle, Margaret River WA

To register, contact Jodie Panel at Wines of Western Australia by fax: 08 9284 4211, phone: 08 9284 3355 or email: reception@winewa.asn.au

If you are interested in bringing a similar workshop to your region, please contact Eric Wilkes, Group Manager – Commercial Services on eric.wilkes@awri.com.au or 08 8313 6600.

Encouraging Chinese consumers to choose Australian wines

Messages about the good quality and taste of Australian wines are most effective in encouraging Chinese consumers to choose Australian wine, compared to other communications about Australia. When consumers in China were told in a magazine article that Chinese people in general prefer the taste of Australian wines, their choice of Australian wine increased significantly over French, Italian and Chinese wines. This key result comes from a collaborative project investigating the impact of different messages about Australia on the wine purchasing behaviour of consumers in China

Apart from the taste message, the next most influential message in encouraging choice of Australian wines was one highlighting Australia’s clean unpolluted environment. An article about Australia’s great beaches and tourist attractions was the least effective, although there was still a positive response compared to a control group. Wine ratings and shelf communication were also shown to be very important for Chinese consumers when choosing a wine to buy.

The project was completed in August with over 1600 Chinese consumers of imported red wine exposed to five different messages about Australia in the form of advertorial-type articles, after which they made purchase selections in a simulated retail situation. The project was conducted by the AWRI sensory team, working with a group of wine industry advisors, as well as Larry Lockshin at UniSA and Simone Mueller-Loose at the University of Aarhus.

The second phase of this project is currently underway and involves consumers tasting Australian, Chinese and French wines under both blind and informed conditions. The results will be presented in another webinar by Patricia in February – watch this space!

Nobel Prize winner to join the AWRI Board

Winemaker and Nobel Prize-winning astronomer, Prof. Brian P. Schmidt, AC, FAA, FRS will join the AWRI Board as a special qualifications director in February 2014.

Brian is a Distinguished Professor at the Australian National University Research School of Astronomy and Astrophysics. He shared the 2011 Nobel Prize for Physics with Saul Perlmutter and Adam G. Riess for the discovery of the accelerating expansion of the Universe. He was elected Fellow of the Royal Society in 2012 and appointed a Companion (AC) in the General Division of the Order of Australia in 2013. He is a non-executive Director of Astronomy Australia, a member of the Council of the Australian Academy of Science and serves on three Government advisory boards.

Brian is also the owner operator of Maipenrai Vineyard and Winery in the Canberra District – a small producer of high quality Pinot Noir wines.

Brian gave the opening address at the 15^th AWITC where he spoke about the importance of creativity and risk-taking in science.

Partnerships bring new opportunities

The AWRI has recently confirmed its involvement in three partnerships, one Australian and two international, that will bring benefits to the Australian wine industry.

The first is a partnership with the Ramaciotti Centre for Genomics at the University of New South Wales which will apply metagenomics techniques to map the composition of wild ferments. This work aims to shed light on the contribution of microbes to wine regional character. Knowledge gained will allow winemakers to take full advantage of local wild yeast and bacteria. It will also enable new yeast and bacteria strains to be developed, drawing on existing regional diversity and the AWRI microbial germplasm collection assembled over the past 50 years.

The second is an international alliance (known informally as the ‘BAG’ alliance) with the Institute of Vine and Wine Sciences (ISVV) (Bordeaux, France) and the Hochschule Geisenheim University (HGU) (Geisenheim, Germany). This partnership will involve cooperation on research areas of mutual interest, exchange of people, projects and information as well as the sharing of infrastructure and expertise across the grape and wine value chain. The Government of South Australia is supporting the new alliance through the Premier’s Research and Industry Fund.

Four areas of priority for collaboration have recently been identified for the BAG alliance:

• Adaptation to climate change
• Management of the spoilage yeast Brettanomyces
• Grapevine trunk diseases
• Consumer behaviour in China

Projects in these four areas will launch early in 2014.

The third partnership is a continuation of the AWRI’s successful collaboration with the Institute of Masters of Wine (IMW), under which the two organisations provide support to each other’s extension and education programs.

The AWRI hosted the IMW’s Australasian seminar in November, and gave a presentation on wine faults and taints to the MW students. Members of the IMW are likely to contribute to AWRI extension events over the next two years. The collaboration also allows the AWRI to access wines that are not available in Australia and import them for use in tasting programs, most recently the successful World Chardonnay and Pinot Noir tasting. In May 2014, Peter Godden will be presenting at the IMW’s 8th Symposium, in a session on the frontiers of wine research.

Well-deserved recognition for Mardi Longbottom

AWRI Viticulturist Mardi Longbottom has received recognition of a very successful 2013 with two awards. She has won a place in the Governor’s Leadership Foundation program for 2014, with a full scholarship provided by Primary Industries and Regions SA (PIRSA). Mardi was also the recipient of the 2013 AWRI Innovation award.

The Governor’s Leadership Foundation (GLF) program contributes to the prosperity of South Australia by inspiring South Australians with leadership potential through enhancing their self-awareness, emotional intelligence, problem solving analysis and strategic foresight ability. The 10-month program is delivered through a mix of:

• seminars;
• forums;
• field trips;
• individual coaching sessions; and
• group work.

The AWRI Innovation award is awarded annually, with a shortlist drawn up based on nominations and voting by AWRI staff, and the final winner chosen by a Board sub-committee. Mardi was recognised for her success in initiating and financing several extension activities of relevance to grapegrowers, adding to the AWRI’s existing service offering to winemakers.

AWRI Annual Report available online

The AWRI’s 2013 Annual Report is now available from the AWRI website. You can download a copy in pdf format or browse through an eBook version.

Recent literature

John Fornachon Memorial Library at the AWRI delivers journal articles and loans books to Australian grapegrowers and winemakers. Books can be searched and requested via the Library catalogue – or you can email the Library with your request. A list of recent AWRI publications follows.

• To order AWRI staff publications and articles from Technical Review please contact the Library
• Articles and books on specific topics can be searched for and ordered via the Library catalogue
• To request a Literature search on a specific topic contact the Library via email or telephone 08 8313 6600.

Recent AWRI staff publications

1569 Mangoni, A.A., Stockley, C.S., Woodman, R.J. Effects of red wine on established markers of arterial structure and function in human studies: current knowledge and future research directions. Expert Rev. Clin. Pharmacol. 6 (6): 613-625; 2013.

1570 Coulter, A. Ask the AWRI: Understanding the ABCs of CMCs in stabilisation. Aust. N.Z. Grapegrower Winemaker (598): p. 72; 2013.

1571 McRae, J.M., Kassara, S., Kennedy, J.A., Water, E.J., Smith, P.A. Effect of wine pH and bottle closure on tannins. J. Agric. Food Chem. 61 (47); 2013.

1572 Kidman, C.M., Mantilla, S.O., Dry, P.R., McCarthy, M.G., Collins, C. The effect of water stress on reproductive performance of Shiraz (Vitis Vinifera L.) grafted to rootstocks. Am. J. Enol. Vitic. doi: 10.5344/ajev.2013.13069; 2013.

1573 Jolly, N. P., Varela, C., Pretorius, I. S. Not your ordinary yeast: non- Saccharomyces yeasts in wine production uncovered. FEMS Yeast Res. doi:10.1111/1567-1364.12111; 2013.

1574 Longbottom, M. Greenhouse gas abatement in viticulture. Aust. N.Z. Grapegrower Winemaker (598): 35-38; 2013.

1575 Muhlack, R., Scrimgeour, N., Wilkes, E., Godden, P., Johnson, D. Optimising fermentation through simulation. Wine Viti. J. 28 (6): 38, 40-43; 2013.

1576 Dry, P. Schönburger. Wine Viti. J. 28 (6): p. 58; 2013.

1577 Viviers, M.Z., Smith, M.E., Wilkes, E., Smith, P. Effects of five metals on the evolution of Hydrogen sulphide, Methanethiol, and Dimethyl sulphide during anaerobic storage of Chardonnay and Shiraz wines. J. Agric. Food Chem. doi.org/10.1021/jf403422x: 12 p.; 2013.

1578 Johnson, D. Fascinating story to tell. Aust. N.Z. Grapegrower Winemaker (599): p. 30; 2013.

1579 Dry, P. If the grape fits then you can grow it. Aust. N.Z. Grapegrower Winemaker (599): p. 57; 2013.

1580 Muhlack, R., Forsyth, K., Scrimgeour, N., Godden, P. There’s gotta be a buck in those organic by-products. Aust. N.Z. Grapegrower Winemaker (599): 80-82; 2013.

1581 Johnson, D. 2013 Report: Planning for the future. Aust. N.Z. Grapegrower Winemaker (598): 81-84; 2013.

1582 Tran, T., Wilkes, E. How does CMC behave in NZ wines? NZ Winegrower (83): 67-69; 2013.

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.