The Australian Wine Research Institute

The Australian Wine Research Institute Blog

eNews – September 2012

3 September 2012 >

The quercetin question for young reds?

Preventing powdery mildew – new option

Wine diversity and complexity through developed yeasts

Good Manufacturing Practice code updated

Benchmarking vineyard greenhouse gas

Portal to unlock grape phenolic potential

Consumer communication tool for Chardonnay?

Attend an AWRI seminar without leaving your office!

Conference explores wine and health relationships

Simple steps: order articles featured in Technical Review

Viticulture book wins international prize

Recent literature

The quercetin question for young reds?

The AWRI’s Winemaking Services team has received recently many samples of red wine bottled early, or bottled within four months of harvest showing quercetin deposits. The deposit is also appearing in a few 2009 red wines. If you have never encountered quercetin deposits before, it could be quite a shock as they appear almost as clumps of yellow-green mould-like material in the bottom of your bottle or wine glass.

Quercetin dihydrate is one of the flavonol compounds which are natural components of grape skins and leaves. Flavonol deposits in wine have been relatively rare, but some modern viticultural practices such as increased sun exposure of fruit, machine harvesting and amount of leaf matter in grape harvests can contribute to elevated levels of these compounds in wine (Ziemelis 1982). Sangiovese seems particularly susceptible to these deposits.

Quercetin glycosides are extracted from the grape skins during fermentation. The quercetin glycosides then hydrolyse in the acidic wine conditions to release the free quercetin. The quercetin may then crystallise, incorporating some water molecules in the process and form a deposit, which precipitates out of the wine and usually ends up in the wine lees. You would never usually notice it. What happens though, if you bottle early, say within four months or so of production, is that the quercetin can remain soluble, the wine can even be sterile filtered, but then can precipitate later in bottle. The deposit looks like mould but is actually crystalline material, looking like this under the microscope:

Unfortunately we do not know of any predictive tests. Once precipitated, the wine can be refiltered to remove the crystals.

Preventing powdery mildew – new option

A new active constituent has been registered in Australia for the control of powdery mildew in grapes. Proquinazid is the same activity group (Group 13) as quinoxyfen but has a much shorter withholding period.

The restriction on use for Talendo for domestic and export wine is ‘Use no later than 28 days before harvest’. The electronic version of the ‘dogbook’ has been updated here. This product is a protectant and will not control existing powdery mildew infections (i.e. between infection and the visible stage). DuPont Australia Ltd or your chemical on-seller will provide more details.

For further information contact Marcel Essling.

Wine diversity and complexity through developed yeasts

Gaining greater control over flavour diversity and complexity of your wine has been made easier through the AWRI’s yeast breeding program. The AWRI has successfully developed non-GM commercial interspecific hybrid yeast strains capable of generating a far wider range of yeast flavour and aroma metabolites than typically observed for the predominant wine yeast, Saccharomyces cerevisiae.

Two of these hybrids have been commercialised previously by AB Mauri Yeast Australia: AWRI 1503 (S. cerevisiae x Saccharomyces kudriavzevii) and AWRI Fusion (S. cerevisiae x Saccharomyces cariocanus). Successful industrial trials on a third hybrid yeast, AWRI 1505 (S. cerevisiae x Saccharomyces bayanus) has led to the planned manufacture of an active dry yeast of this hybrid strain (re-named ‘AWRI Cerebay’) in time for the 2013 Australian vintage. Please contact Jenny Bellon to learn more about how these novel hybrids can be used to differentiate your wine from others in the marketplace.

Good Manufacturing Practice code updated

The AWRI has completed the revision of the Code of Good Manufacturing Practice for the Australian grape and wine sector, together with a small group of winemakers selected from the Wine Industry Technical Advisory Committee. The revised and expanded, 21-page second edition of the Code is available electronically on the AWRI website.

Benchmarking vineyard greenhouse gas

The three major greenhouse gases produced by agricultural activities are carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), which are absorbed and emitted from plants and soils as a result of plant and microbial metabolic activities and management practices. Reducing the potent N2O emissions from vineyard activities is the focus of a DAFF ‘Action on the Ground’ funded project led by AWRI’s Mardi Longbottom.

This project will enable measurement of the nitrous oxide emissions from a range of vineyard scenarios taking into consideration factors such as soil type, fertiliser practices, ground cover and soil moisture. Five grapegrowing regions will be included in the study to cover a broad range of conditions. The aim of this work is to establish baseline N2O emissions levels and identify and recommend those practices which have the potential to reduce production of this potent greenhouse gas.

For further information contact Mardi Longbottom.

Portal to unlock grape phenolic potential

Colour, tannin and phenolic levels in red grapes are all indicators of quality. A number of small-scale vineyard trials, conducted by the AWRI’s Tasmania Node, have highlighted the impact that soil type, clone, rootstock selection and weather patterns can have on colour, tannin and phenolics in red grapes during ripening. A sound knowledge of these aspects could be used to spread the harvest over a more extended period and to target a particular maturation window and phenolic profile in the grapes.

One particular study was carried out to determine the influence of five clones and four rootstock types on Pinot Noir maturation at a site in the Coal River Valley, Tasmania, in 2009 and 2010. Results showed that the choice of both clone and rootstock was important for colour (anthocyanins) and tannin development in the grapes. The clone type had a more significant effect than rootstock on the rate of ripening and resultant phenolics within a particular vintage. The impact of rootstock selection varied with the vintage.

Figure 1: the effect of five different clone types and four rootstocks on ripening during 2009 and 2010.

Analysis of the grape homogenates was carried out using a brand new rapid method involving UV-Vis measurement and application of complex algorithms to determine the level of anthocyanins, phenolics and tannins in the grapes.

The AWRI is currently developing a web-based tool (the Grape Portal) that will provide opportunities for these attributes to be closely monitored and analysed during ripening. It will also allow users to track and securely store standard grape maturity measures such as pH, TA and Brix. This will help to ensure that effective and informed decisions can be made on harvesting time and logistics associated with winery processing operations.

The Grape Portal will be the second module made available to producers through a web-based interface. This follows the success of the Tannin (Wine) Portal, launched in 2010, which allows wine producers to measure the level of tannins, phenolics and colour (pigments) in their red ferments and finished wines. Both tools are supported by simple and rapid analysis methods, carried out at the winery, which provide valuable process data and allow winemakers to make informed decisions to achieve enhanced structure and mouth-feel in their wines.

Users of the Tannin Portal have benefitted from the extensive database of wines which has been built up (currently over 10,000 samples), allowing them to benchmark the attributes of their wines against others by a combination of vintage, variety and region. The Grape Portal will include this important function, as well as additional graphical tools that will allow simple generation of grape maturity trends and attribute profile charts. Further information can be obtained from Neil Scrimgeour.

Consumer communication tool for Chardonnay?

Following the success of the Pinot G Style Spectrum, which was developed as a label device to communicate wine style to consumers, the concept has been extended to Chardonnay. The AWRI is developing a simple way of translating the complex attributes of Chardonnay wine into a single linear scale that can be used to classify its style and inform consumer expectations.

A tasting was conducted with representatives from Treasury Wine Estates, Yalumba and Premium Wine Brands using a set of 20 commercial Chardonnay wines. A further evaluation of twelve of those wines was made using the AWRI’s trained sensory panel and all the wines were subjected to chemical and spectral analysis. The spectral information has been used to define a fingerprint of the compositional variables in Chardonnay which is then converted into a simple rating which correlates with the sensory characteristics of the wines.

Analysis of the resulting data confirms that Chardonnay wine style could realistically be rated and communicated via a similar labelling device to the Pinot G Style Spectrum, allowing consumers to select their Chardonnay wine based on their preferred style.

The Pinot G Style Spectrum was developed as a way of engaging with and informing consumers on the style of wine they can expect when they open a bottle. The Spectrum label device informs consumers of the expected style of the wine in the bottle at point of sale and was developed in response to industry demand from producers who were concerned that the two names being used for the same grape variety was causing confusion in the marketplace.

Figure 2: The Pinot G Style Spectrum used to classify wine style from Crisp to Luscious.

A preliminary market assessment has indicated that there is interest from producers for the Pinot G Style Spectrum technology to be extended to Chardonnay wines. The AWRI is seeking industry support for further development and refinement of this tool and a commitment to use it, once developed, for marketing purposes.

Those interested should contact Dr Eric Wilkes, Commercial Services Manager either by email or by telephone on (08) 8313 6600.

Attend an AWRI seminar without leaving your office!

The AWRI’s annual webinar program has kicked off. With 15 webinars on topics as diverse as winemaking at low pH, phosphorous acid, protein haze and cold stabilisation, the presentations are tailored to meet a wide range of industry needs and interests.

This year we have invited industry guests to present, and are pleased to announce that Tony Battaglene (WFA), Steve Guy (Wine Australia) and Lawrie Stanford (WGGA) have joined the program. There is no fee to attend an AWRI webinar, but registration is essential. Click here to register and view the program in full.

Conference explores wine and health relationships

Twenty years after the term the ‘French Paradox’ was coined, scientific studies continue to explore the complex relationship between the consumption of wine and health. This relationship has been the focus of a long standing series of international scientific meetings from 1996 to 2010 in Italy, USA, Chile, South Africa and France. The next in this series of meetings, WineHealth 2013, is to be held in Sydney, Australia from 18-21 July 2013 at the Sydney Exhibition and Convention Centre immediately following the AWITC.

This WineHealth 2013 Conference gathers world experts for a stimulating exchange of scientific information and ideas on the impacts of wine consumption on human health, and to explore the effect of wine as a unique alcoholic beverage.

The Conference also aims to provide deeper insight into the biological mechanisms involved in any beneficial effects of wine on health, and how specific molecules present in grapes and wine have biological activities that may be harnessed for health. Sociological outcomes of the use and abuse of wine, and hence public health priorities will also be presented for debate and discussion.

It is envisaged that these exchanges will contribute to the evidence base for public policy setting, provide direction for new research efforts into the health effects of wine, and offer opportunities for international collaborations. Delegates will be drawn from the dietician, nutrition and medical fraternities, from public health, as well as from industry and research.

The WineHealth 2013 conference program commences on the Thursday afternoon, immediately following the conclusion of the Australian Wine Industry Technical Conference, and then concludes on the Saturday evening, with a networking event planned for the Sunday.

For further information about WineHealth 2013, please visit the website or contact Creina Stockley or Kate Beames.

Simple steps: order articles featured in Technical Review

The AWRI’s Technical Review summarises papers and articles recently published of interest to grape and wine producers. Have you browsed through the Current Literature section of Technical Review before and found articles of interest, but thought it was too hard to obtain a copy of the full paper? The AWRI has now made it even easier for you!

Each issue of Technical Review can be downloaded from The Australian Wine Research Institute website. A simple online ordering system has recently been added to the website to allow producers to request articles listed in Technical Review’s ‘Current Literature’ and ‘AWRI Publications’.

To order an article – access the current issue of Technical Review via the following link : https://www.awri.com.au/information_services/technical_review/current-edition/.

  • To view the content in each section click on the triangle next to each heading.
  • Click on the title of an article to access the details and abstract.
  • To order click on add to cart.
  • You can scroll through the articles in each section by clicking on the arrows located on the bottom left hand corner.
  • Click on view cart to place your order or return to the current issue by clicking on the button on the bottom right hand corner to continue reading.

Articles from previous issues of Technical Review can be searched and ordered via the following link : https://www.awri.com.au/information_services/technical_review/cl/. If you need further assistance, contact Anne or Michael from the AWRI’s Information Services team via email.

Viticulture book wins international prize

The book ‘The Grapevine: from the science to the practice of growing vines for wine’ has received international recognition by winning an Organisation Internationale de la Vigne et du Vin (OIV) prize in the viticulture section of the OIV 2012 book awards. The book is written by four of Australia’s leading viticulture scientists — Dr Patrick Iland, the AWRI’s Dr Peter Dry, Dr Tony Proffitt and Professor Steve Tyerman.

Each year, the OIV awards prizes to books that have made a significant contribution to the knowledge of a particular discipline and that are judged to be the best books published in each discipline for that year. ‘The Grapevine: from the science to the practice of growing vines for wine’ was judged as providing a comprehensive review of the literature and its application to the practice of viticulture.

The authors provide an up-to-date, thoughtful, comprehensive and interesting account of the scientific principles relating to the practice of viticulture. The book is of interest to a wide range of people including scientists, students and practitioners and to anyone involved in viticulture and winemaking as, while it focuses on theory, it also contains practical aspects of growing vines for wine.

Further information about the book can be found on the publisher’s website.

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 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

Bindon, K.A., Smith, P.A. Comparison of the affinity and selectivity of insoluble fibres and commercial proteins for wine proanthocyanidins Food Chemistry http://dx.doi.org/10.1016/j.foodchem.2012.08.016: 1-42; 2012.

Bindon, K.A., Bacic, A., Kennedy, J.A. Tissue-specific and developmental modification of grape cell walls influences the adsorption of proanthocyanidins. Journal of Agricultural and Food Chemistry DOI: 10.1021/jf301552t: 1-45; 2012.

Callegari S., Gregory P.A., Sykes M.J., Bellon J.R, Andrews S., McKinnon R.A, de Barros Lopes MA. Polymorphisms in the mitochondrial ribosome recycling factor EF-G2mt/MEF2 compromise cell respiratory function and increase Atorvastatin toxicity. PLoS Genetics 8 (6): 1-12; 2012.

Capone, D.L., Sefton, M.A., Jeffery, D.W. Analytical investigations of wine odorant 3-Mercaptohexan-1-ol and its precursors. Qian, M.C., Shellhammer, T.H. (Editors) Flavor chemistry of wine and other alcoholic beverages.: ACS Symposium Series 1104: 15-35; 2012.

Capone, D.L., Francis, I.L., Herderich, M.J., Johnson, D.L. Managing eucalyptus aromas. Wine & Viticulture Journal 27 (4): 22-27; 2012.

Carew, A., Smith, P., Dambergs, B. Yeast selection impacts phenolics in Pinot Noir. Australian & New Zealand Grapegrower & Winemaker (581): 70-72; 2012.

Cox, C.M., Favero, A.C., Dry, P.R., McCarthy, M.G., Collins, C. Rootstock effects on primary bud necrosis, bud fertility, and carbohydrate storage in shiraz. American Journal Enology and Viticulture 63 (2) : 277-283 ; 2012.

Cozzolino, D., Curtin, C. The use of attenuated total reflectance as tool to monitor the time course of fermentation in wild ferments. Food Control, 26 (2), 241-246; 2012.

Dry, P. Petit Manseng. Wine & Viticulture Journal 27 (3): p. 63; 2012.

Dry, P. Negro Amaro. Wine & Viticulture Journal 27 (4): p. 65; 2012.

Essling, M. Assessing sun-smart protection. Australian & New Zealand Grapegrower & Winemaker (581): 36-37; 2012.

Henschke, P.A., Varela, C., Schmidt, S., Siebert, T., Kalouchova, R., Curtin, C.D., Francis, I.L., Torrea, D., Ancin-Azpilicueta, C., Vilanova, M., Ugliano, M. Albarino – Chardonnay: Modulating wine style with DAP. Practical Winery & Vineyard 33 (3): 14-22; 2012.

Herderich, M.J., Siebert, T.E., Parker, M., Capone, D.L., Jeffery, D.W., Osidacz, P., Francis, I.L. Spice up your life: analysis of key aroma compounds in Shiraz. Qian, M.C., Shellhammer, T.H. (Editors) Flavor chemistry of wine and other alcoholic beverages.: ACS Symposium Series 1104: 3-13; 2012.

Herderich, M.J., Curtin, C., Hayasaka, Y., Mercurio, M. Metabolomics and the quest for understanding wine quality. Oeno2011- Actes de colloques du 9e symposium international d’oenologie de Bordeaux, Dunod, Paris, 609-614; 2012.

Holdstock, M. Constant observation key to avoiding dilemma of stuck ferments. Australian & New Zealand Grapegrower & Winemaker (582): 66-67; 2012.

Krstic, M. Precision management technologies prove their value in selective harvesting in Australia’s major production regions. Wine & Viticulture Journal 27 (4): 34-36; 2012.

Muhlack, R. Reduce vintage costs and improve process control with new ferment simulation tool. Australian & New Zealand Grapegrower & Winemaker (582): 62-65; 2012.

Rojas, I.B., Smith, P.A., Bartowsky, E.J. Influence of yeasts on volatile fermentation-derived compounds, colour and phenolics composition in Cabernet Sauvignon wine. World Journal of Microbiology and Biotechnology DOI 10.1007/s11274-012-1142-y: 1-11; 2012.

Tran, T.M.T., Stanley, G.A., Chambers, P.J., Schmidt, S.A. A rapid, high-throughput method for quantitative determination of ethanol tolerance in Saccharomyces cerevisiae. Annals of Microbiology DOI: 10.1007/s13213-012-0518-4: 1-; 2012.

Ugliano, M., Dieval, J-B. , Siebert, T.E., Kwiatkowski, M., Aagaard, O., Vidal, S., Waters, E.J. Oxygen consumption and development of volatile sulphur compounds during bottle aging of two shiraz wines. Influence of pre- and postbottling controlled oxygen exposure. Journal of Agricultural and Food Chemistry DOI:10.1021/jf3014348: 1-10; 2012.

Varela, C., Kutyna, D.R. Solomon, M., Black, C.A., Borneman, A., Henschke, P.A., Pretorius, I.S., Chambers, P.J. Evaluation of gene modification strategies to develop low-alcohol wine yeasts. Applied and Environmental Microbiology doi:10.1128/AEM.01279-12: 1-38; 2012.

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.

AWRI 2012 Webinar Series

9 August 2012 >

2012 AWRI Webinar series

Webinar is an interactive tool enabling you to participate in a live seminar from your desk using a computer with Internet access.

The AWRI’s webinars cover a range of winemaking, winery management, viticulture, and wine and health topics. Each webinar consists of a presentation followed by a Q&A session and is held on a Tuesday or Thursday at 11:30am Australia Central Daylight Time (Adelaide, GMT+9:30).

Register now to participate in our upcoming webinars:

Presentation: Vineyard characteristics used in assessment schemes: theory and practice
Presenter: Peter Dry
Date: 21/08/2012

Presentation: Effective oxygen management at bottling
Presenter: Warren Roget
Date: 23/08/2012

Presentation: Winemaking with non-conventional yeast
Presenter: Jenny Bellon
Date: 28/08/2012

Presentation: How can irrigation management strategies be used to manipulate wine quality?
Presenter: Marcel Essling
Date: 4/09/2012

Presentation: Protein haze in white wines: new solutions to an old problem
Presenter: Matteo Marangon
Date: 11/09/2012

Presentation: Practical management of ‘Brett’ in the winery
Presenter: Chris Curtin
Date: 20/09/2012

Presentation: Harmonising maximum residue limits in agrochemicals: Phosphorous acid and beyond
Presenter: Tony Battaglene (Winemakers’ Federation of Australia)
Date: 25/09/2012

Presentation: Cold Stability, how to manage and measure it
Presenter: Eric Wilkes
Date: 4/10/2012

Presentation: Tips for successful wine exporting
Presenter: Steve Guy (Wine Australia)
Date: 9/10/2012

Presentation: Putting the texture back into white wine – the role of white wine phenolics
Presenter: Richard Gawel
Date: 16/10/2012

Presentation: Crafting diverse wine styles through an understanding of how grape composition affects wine composition
Presenter: Paul Smith
Date: 23/10/2012

Presentation: The Pinot G Style Spectrum; a novel tool to communicate wine style to consumers
Presenter: Peter Godden
Date: 30/10/2012

Presentation: Making better wine for health
Presenter: Creina Stockley
Date: 6/11/2012

Presentation: Winemaking at low pH: avoiding stuck fermentations in whites and sparkling wines
Presenter: Simon Schmidt
Date: 13/11/2012

Further information or to register
For further information or to register, please visit our website at https://www.awri.com.au/industry_support/courses-seminars-workshops/webinars/.

Registration confirmation

After registration, you will receive a confirmation email with details on how to join the session.

System requirements
You will need a computer with Internet connection and audio is connected via your computer’s microphone and speakers (Voice over IP – VOIP). A headset is highly recommended. You can also access the audio via a toll free number.

Agrochemical update August 2012

8 August 2012 >

All changes to the AWRI publication ‘Agrochemicals registered for use in Australian viticulture’ (aka ‘Dog Book’) are shown on the electronic version available from the AWRI website. Amendments are highlighted by a red asterix (*).

New active

PROQUINAZID

APVMA 64165

Talendo has been granted registration by the Australian Pesticides and Veterinary Medicines Authority (APVMA) for control of Powdery Mildew in grapevines.

Talendo is a DuPont Australia Ltd product. It contains the active constituent proquinazid which is a Group 13 fungicide that should be used as a protectant treatment only.

Restriction on use for export grapes: Use no later than 28 days before harvest.

Resistance management strategy: DO NOT apply more than two consecutive sprays of a Group 13 fungicide. DO NOT apply more than three Group 13 sprays per season.

New products

AZOXYSTROBIN

APVMA 66965

Azoxystrobin 250 SC has been granted registration for use against Powdery Mildew, Downy Mildew and Botrytis in grapevines by the APVMA. This Agspray Pty Ltd product is a Group 11 fungicide with azoxystrobin as active constituent.

Restriction on use for export grapes: Use no later than 80% capfall.

TEBUCONAZOLE

APVMA 67455

Laguna Xtreme 800 WG has been granted registration for use against Powdery Mildew in grapevines by the APVMA. This Sipcam Australia Pty Ltd product is a Group 3 fungicide with tebuconazole as active constituent.

Restriction on use for export grapes: Use no later than 80% capfall.

This information is provided to inform the Australian grape and wine sector of agrochemical information, and should not be interpreted as an endorsement.

Technical Review: August 2012 issue now available online

7 August 2012 >

The August 2012 issue of Technical Review is now available for viewing online and for downloading. Access is available only to Australian winemakers and grapegrowers who pay the Wine Grapes or Grape Research levies.

The new online Technical Review allows you to browse the list of the latest articles on grape and wine production by keyword, view article summaries and order journal articles from the AWRI Library.

To access the issue, click here.

eNews – July 2012

2 July 2012 >

AWRI in review

Transport taints

Phenolics – friend or foe?

Brilliance beyond bentonite

Leveraging Lactobacillus

The ABC of MRLs

AWRI website makeover

Out of the ordinary

AWAC alumni grows

International influence

Olympic odyssey

Recent literature

AWRI in review

As most of our industry colleagues would be aware, the AWRI receives the majority of its funding from a combination of levies collected from winemakers and grapegrowers, with matching funds from the Australian government. The body who is responsible for the prudent investment of these funds, the Grape and Wine Research and Development Corporation, has recently undertaken a formal review of the current investment agreement between the GWRDC and the AWRI. The review, which was undertaken in May, was welcomed and embraced by the AWRI and involved a large number of industry personnel. Whilst the review findings are not yet finalised, a sincere thanks goes to those industry members who contributed to the process.

Transport taints

Over the past 12 months, the AWRI’s Winemaking Services team has received an increase in the number of wines submitted with taints presumed to have occurred during transport overseas in flexitanks. Appropriate sampling of wine before and after transport will assist in identifying the culprit.

There are several reasons as to why wineries choose to transport their wine overseas in bulk. The wine is typically transported in flexible tanks (wine bladder), more commonly known as flexitanks. Occasionally, some of these wines appear to be tainted when they arrive at their destination. The taint is usually a hydrocarbon one, but can be a chloroanisole or chlorophenol taint. It might be that the flexitanks are exposed to a tainted environment and that the taint goes through the bag to taint the wine. Alternatively, the flexitank wine bladder might have previously been exposed to a taint, which it then releases into the wine during transport. Either way, it is difficult to prove the wine became tainted during transport unless the right samples are submitted for analysis.

Samples of the wine from the flexitank, once it is filled, should be taken and kept as ‘holdback’ samples. Then, once the wine arrives at the destination, further samples should be taken from the tank. In this way, if the wine appears to be tainted after unloading, the ‘holdback’ and ‘destination’ samples can be tested and the results compared.

The AWRI’s investigative team is here to help. Contact us should you require any further information or assistance.

Phenolics – friend or foe?

A new report by the AWRI contradicts widely held assumptions about phenolics in white wines – particularly their assumed effects on astringency. The collaborative research project with Orlando Wines has shed new light on the impact of phenolic compounds in white wine which may allow winemakers to better manage palate texture in their wines.

The effects of the phenolic composition, alcohol and acidity levels of white wines on their mouth-feel and bitterness were assessed by a team of researchers at the AWRI using experimental winemaking, sensory, and advanced compositional analysis. The key findings were that low pH enhanced astringency, while the presence of two major phenolics in Australian white wines either increased palate ‘oiliness’ (Grape Reaction Product [GRP]) or suppressed ‘hotness’ (caftaric acid).

The AWRI researchers made experimental wines over three vintages which clearly exhibited a range of ‘phenolic’ characters. From these wines, the researchers isolated GRP and caftaric acid. These wines and phenolic compounds were used to identify correlations with sensory ratings and explore the role played by pH and alcohol on phenolic taste and texture.

In the wines made using methods designed to alter their phenolic content (i.e. pressings, hyperoxidation, skin contact), the perception of astringency was found to be far more influenced by pH than by the total amount of phenolics. Increased skin contact led to more phenolics, as expected, but unexpectedly astringency decreased and viscosity increased, mostly due to the pH increase (caused by potassium extraction from skins). However, wines to which 30% more phenolics were added were more astringent, but overall, this significant increase in total phenolics induced a relatively small increase in astringency compared to that caused by pH. The increase in astringency resulting from adding phenolics was greater in higher pH wines, once again highlighting the importance of pH on astringency. Higher pH was also associated with higher viscosity, further emphasising the importance of pH on the perception of mouth-feel in white wines. GRP was found to increase the impression of oiliness in model wine. Palate hotness or ‘burning after taste’ is most highly associated with alcohol concentration. High phenolic levels also appeared to slightly enhance the hot palate sensation, but in a further discovery, the major phenolic in white wine, caftaric acid, actually suppressed alcohol hotness. Bitterness was generally positively associated with phenolics, although not for the two major phenolics in Australian white wines (GRP and caftaric acid). This implicates some other phenolics whose identity remains unknown in white wine.

The report detailing the research carried out is now available on the GWRDC website.

Brilliance beyond bentonite

The search for alternatives to bentonite for wine protein fining has recently produced some exciting results. The AWRI has been testing two new strategies for protein removal from juices/wines that show excellent promise to become viable tools for winemakers.

The AWRI has proven that a polysaccharide from seaweeds, carrageenan, can remove proteins from juices/wines very effectively. It was also found that juice flash pasteurisation combined with an enzymatic treatment succeeded in stabilising wines too. Following these two very different approaches, the AWRI has been able to obtain wines that did not need bentonite fining, without inducing major changes on the chemical or sensorial attributes of the wines treated.

Read the latest on the work into new solutions for preventing wine protein haze in the following publications: Australian Journal of Grape and Wine Research, 18 (2), 194-202; Grapegrower and Winemaker, 580, 71–73; Food Chemistry, DOI 10.1016/j.foodchem.2012.05.042; or contact the John Fornachon Memorial Library or Dr Matteo Marangon for more information.

Leveraging Lactobacillus

Lactobacillus species are usually associated with wine spoilage, however, this species is able to conduct malolactic fermentation (MLF) in wine. In fact, a Lactobacillus plantarum strain has recently been introduced as a commercial MLF starter culture. A recent collaboration with an Italian visiting scientist is providing information on how to use these tough bacteria to our advantage.

In order to have a better understanding of how Lactobacillus strains survive in wine, a screening of Lactobacillus strains in the AWRI Wine Microorganism Culture Collection was undertaken in collaboration with an Italian visiting scientist, Mr Alessandro Moncalvo (Università Cattolica del Sacro Cuore, Piacenza). Using high throughput screening techniques developed in the AWRI Biosciences Team, Alessandro screened over 35 Lactobacillus strains (which had been collected over many years) for their ability to grow at 18-28°C; tolerance to ethanol; SO2; and pH in defined medium. As predicted, a range of phenotypes was observed. Several strains were selected for further characterisation in a red wine for their ability to survive and complete MLF. These strains are currently being identified to species level. This study will provide an important insight into how Lactobacillus survive and proliferate in wine, and will provide a better understanding to minimise their ability to spoil wine.

The ABC of MRLs

Avoid the bite of maxing out on residue levels in your wine. The AWRI’s ‘dog book’ Agrochemicals for use in Australian viticulture 2012/2013 has just been published and is also available online.

AWRI website makeover

Have you visited the AWRI’s website before? The AWRI website has had a major overhaul and information and resources for winemakers, grapegrowers, wine exporters and consumers are now easier to find and use. It is definitely worth revisting: http://www.awri.com.au.

The AWRI website contains over 12,000 pages of information. Information is easily found through the various new sections of the website:

‘Resources for Vineyards’

Why would you visit? See information and resources on: Advice and support; Agrochemicals; Analytical Services; Viti-Note Factsheets; Library and Information Services; Seminars and Workshops.

‘Resources for Wineries’

Why would you visit? See information and resources on: Advice and support; Aroma and flavor; Consultancy Services; Frequently Asked Questions; Fermentation; Laboratory establishment and methods; Library and Information Services; Online tools and databases; Packaging; Regulatory advice and support; Seminars and workshops; Sensory assessment.

‘Resources for Exporters’

Why would you visit? See information and resources on: Advice and support; Analytical services; Library and Information Services; Seminars and workshops.

‘Resources for Consumers’

Why would you visit? See information and resources on: Advice and support; Wine and health information; Library and Information Services.

Information and resources can also be found under:

About us: containing AWRI corporate information.

Research and Development: details of the AWRI’s research program and the development of research outcomes for uptake by Australian grape and wine producers.

Industry Support and Education: details of extension activities including Roadshows, seminars, workshops; resources for winemakers; winemaking advice and problem solving; online videos; and the Advanced Wine Assessment Course.

Commercial Services: details of analytical and sensory services; process optimisation; proof of performance; environmental strategy; and packaging solutions.

Information Services: find AWRI publications such as Technical Review and the Annual Report; staff publications; eBulletins; eNews; Factsheets; Grape and Wine search portal; Library Services to levy payers; and the online image collection.

Our people and employment: details of positions vacant at the AWRI and profiles of AWRI staff.

Is there something missing on our website that you would find useful? Contact us and let us know.

Out of the ordinary

Both grapegrowers and wine producers are generally enthusiastic about new grape varieties. However, wine marketers and sommeliers tend to have a more conservative approach. In order to convince wine marketers of the merits of Alternative Varieties, a special ‘Research to Practice’ workshop was presented on 12 June at the AWRI.

The audience comprised seven marketers from small to large wine companies and representatives from Barossa, Limestone Coast and Riverland regions and Wine Australia. The workshop provided a forum for discussion of the challenges faced by wine marketers in educating consumers about new varieties. For more information contact Dr Mardi Longbottom.

AWAC alumni grows

Do you want to benchmark your wine sensory ability in a rigourous, quantifiable manner? Do you know your sensory assessment strengths and weaknesses? Or, are you keen to contribute to the wine show system as a wine judge? Another 30 industry members came closer to their goals after completing the recently-held 31st AWRI Advanced Wine Assessment Course in June. Forty hours over four days including a new wine bracket, lively and interesting discussions and structured and assessed tutored tastings were a feature. Congratulations to all those who participated and are now part of the 930 who have completed the course since it first began.

The 31st AWAC settled into its new home at the Adelaide Showgrounds, also home to the Royal Adelaide Wine Show. The quality of the discussions – thanks to the great line up of guest judges and active participants – ensured the four days of the course were not only interesting and lively but of maximum value. Check out some of the comments @The_AWRI #AWAC twitter account.

Participants were also treated to the addition of a new bracket of Moscato wines, and Con Simos was joined in leading the discussion by the AWRI’s Matt Holdstock and Geoff Cowey.

Congratulations again to Peter Lehmann Wines, who followed up receiving the ‘Wine of the 30th AWAC’ with their 2003 Peter Lehmann Margaret Semillon being awarded the ‘Wine of the 31st AWAC’. The AWRI will shortly be announcing the 31st AWAC Dux who will be offered a place as an associate judge at the Royal Adelaide Wine Show.

The next AWAC course will be held in November, which promises to be even better, with some new advancements to the course now in the pipeline.

All positions in this AWAC are currently filled so if you aren’t already registered for our ballot for future AWACs, make sure you enter your name here.

International influence

The AWRI’s Health and Regulatory Information Manager, Creina Stockley, was elected to the position of President of Commission IV – Safety and Health at the OIV (Organisation Internationale de la Vigne et du Vin) General Assembly held in Izmir, Turkey last weekend. This is a three year appointment which effectively increases Australia’s influence in the wine and health and food safety arenas, as well as maintains Australia’s membership of the OIV Bureau, the peak scientific committee of the 45 member-country OIV.

Creina has been an Australian delegate and expert to the OIV since 1999, but has been informally involved since 1991 when she commenced at The Australian Wine Research Institute. A clinical pharmacologist/toxicologist, she has been Vice-President and acting President of the Nutrition and Wine expert group (2000-2006) and is currently President of the Food Safety expert group (since 2007).

Olympic odyssey

Best wishes go to the AWRI’s Customer Services Manager Commercial Services, Matthew Cream, as he and his family prepare to fly out to London to participate in the Olympic Games. Matthew has been selected to be among the 16 trios of match officials to referee the Football.

p>After arriving in London on 19 July, Matthew will receive training and instruction prior to the first matches scheduled to start on 26 July, the day before the opening ceremony. The 16 trios of match officials will cover the 32 matches, so it is likely we’ll see Matthew officiating in two matches and perhaps another two as reserve. Matches will be held in London, Cardiff, Coventry, Manchester, Newcastle and Glasgow. Matthew has been a FIFA Assistant Referee able to officiate in international matches since 2000, with the 2005 and 2009 FIFA Confederations Cup 3rd v 4th matches being highlights. Good luck Matthew!

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 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

Bartowsky, E., Costello, P., Francis, L., Travis, B. Oenococcus oeni and Lactobacillus plantarum : Effects of MLF on red wine aroma and chemical properties. Practical winery & vineyard 33 (2) : 57-59; 2012.

Coulter, A. Laccase and rot: Is it there or is it not? Australian & New Zealand grapegrower & winemaker (579): 69-72 ; 2012.

Cowey, G. How and why identify matter other than grapes. Australian & New Zealand grapegrower & winemaker (580): 77-78 ; 2012.

Cozzolino, D., Cynkar, W.U., Shah, N., Smith, P. Multivariate data analysis applied to spectroscopy : potential application to juice and fruit quality. Food research international 44 (7) : 1888-1895 ; 2011.

Curtin, C., Kennedy, E., Henschke, P.A. Genotype-dependent sulphite tolerance of Australian Dekkera(Brettanomyces) bruxellensis wine isolates. Letters in applied microbiology 55 (1): 56-61; 2012.

Curtin, C. D. Borneman, A. R. Henschke, P. A. Godden, P. W. Chambers, P. J. Pretorius, I. S. Advancing the frontline against Brett : AWRI breakthrough offers potential to transform the battle against Brett. Practical winery & vineyard 33 (2) : 47-48, 50-54, 60; 2012.

Curtin, C. Borneman, A. Chambers, P. Pretorius, S. Winning at snakes and ladders. Practical winery & vineyard 33 (2) : 55-56; 2012.

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. Applied spectroscopy 66 (6) : 656-664 ; 2012.

Dambergs, R., Sparrow, A., Carew, A., Scrimgeour, N., Wilkes, E., Godden, P., Herderich, M., Johnson, D. Quality in a cool climate –maceration techniques in Pinot Noir production. Wine & viticulture journal 27 (3) : 18, 20-26 ; 2012.

Henschke, P.A., Varela, C., Schmidt, S., Torrea, D., Vilanova, M., Siebert, T., Kalouchova, R., Ugliano, M., Ancin-Azpilicueta, C., Curtin, C.D., Francis, L. Modulating wine style with DAP: case studies with Albariño and Chardonnay. Australian & New Zealand grapegrower & Winemaker (581): 57-58, 60-63; 2012.

Henschke, P., Bellon, J., Curtin, C., Chambers, P. Breeding for success: yeast strain development at the AWRI. Wine & Viticulture Journal 27(3): 35-39 ; 2012.

Krömer, J.O., Nunez-Bernal, D., Averesch, N.J.H., Hampe, J., Varela, J., Varela, C. Production of aromatics in Saccharomyces cerevisiae — A feasibility study. Journal of biotechnology doi.org/10.1016/j.jbiotec.2012.04.014: 1-10 ; 2012.

Longbottom, M. Mixed cost and quality effects from thinning. Australian & New Zealand grapegrower & winemaker (579): 52 ; 2012.

Marangon, M., Lucchetta, M., Duan, D., Stockdale, V.J., Hart, A., Rogers, P.J., Waters, E.J. Protein removal from a Chardonnay juice by addition of carrageenan and pectin. Australian journal of grape and wine research 18 (2) : 194-202; 2012.

Marangon, M., Pocock, K. F., Waters, E.J. The addition of bentonite at different stages of white winemaking and its effect on protein stability. Australian & New Zealand grapegrower & winemaker (580) : 71-73; 2012.

Marangon, M., van Sluyter, S.C., Robinson, E.M.C., Muhlack, R., Holt, H., Haynes, P.A., Godden, P.W., Smith,
P.A., Waters, E.J. Degradation of white wine haze proteins by a glutamic acid peptidase during juice flash pasteurization. Food chemistry doi.org/10.1016/j.foodchem.2012.05.042: 1-42; 2012.

Pretorius, I.S., Curtin, C.D., Chambers, P.J. The winemaker’s bug : from ancient wisdom to opening new vistas with frontier yeast science. Bioengineered bugs 3 (3): 147-156; 2012.

Scarlett, N., Bindon, K. Case study of vigour-based zonal vineyard management and phenolic variation in wine Wine & Viticulture Journal 27(3): 41-43 ; 2012.

Schmidt, S.A., Jacob, S.S., Ahn, A.B., Rupasinghe, T., Krömer, J.O., Khan, A., Varela, C. Two strings to the systems biology bow: co-extracting the metabolome and proteome of yeast. Metabolomics DOI 10.1007/s11306-012-0437-1:1-16; 2012.

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.

Agrochemical update June 2012

19 June 2012 >

Strobilurin-resistance management:

The identification of strobilurin-resistant powdery mildew in Australia has led to a new resistance management strategy for Group 11 fungicides from the CropLife Australia Fungicide Resistance Management Review Group. Growers who have applied strobilurins routinely over many seasons should be particularly aware of the new guidelines.

The latest resistance management strategy outlines:

  • Apply Group 11 and other systemic fungicides preventatively.
  • DO NOT apply more than two sprays per season of Group 11 fungicides.
  • Where Group 11 products have been routinely used for many seasons, field research indicates there is an increased risk of powdery mildew resistance to Group 111 fungicides occurring. To ensure continued protection against powdery mildew in these circumstances, mix Group 11 fungicides with a registered rate of a compound from an alternative chemical group for the control of powdery mildew in grapes.
  • Alternatively, if applied alone, Group 11 fungicides should be used in strict alternation with fungicides from an alternative chemical group for the control of powdery mildew in grapes.

The active constituents registered for use in viticulture in the Group 11 category are azoxystrobin, trifloxystrobin and pyraclostrobin.

DOG BOOK: Agrochemicals registered for use in Australian Viticulture 2012/13.

The details below list the significant changes to the published booklet.

New restriction on use:

Cyprodinil + fludioxonil

Switch

APVMA 51797, registered for control of botrytis.

The recommended restriction on use is: Use no later than E-L 29, berries pepper-corn size (4 mm in diameter). Do not use within 60 days of harvest.

Removed:
Flusilazole

Nustar DF

No longer registered by the APVMA and not permitted for use in powdery mildew control.

New targets and active combinations:
Spinetoram (Delegate) is listed for Grapevine Moth. The recommended restriction on use is: Use no later than E-L 31, berries pea-size (7 mm in diameter).

Captan + Metalaxyl (Duplex WG) is listed for Black spot, Botrytis bunch rot, Downy mildew and Phomopsis cane and leaf spot. The recommended restriction on use is: Use no later than 30 days before harvest.

New pests:
Recommended control options for Mealybug and Snail are now listed in the Recommendations section of the booklet.

Resistance management strategies:

The resistance management strategy issued by CropLife Australia for Downy mildew has changed. Sprays can now commence from E-L 12 (Shoots 10 cm). Start disease control sprays using a protectant or non-phenylamide fungicide and continue spraying at 7 – 21 days depending on disease pressure and rate of grapevine growth, typically when shoots are 10 cm (E-L 12 stage) or longer.

The resistance management strategy for Powdery mildew now includes Group 7 (carboxamide) fungicides. DO NOT apply consecutive sprays of Group 7 fungicides, including from the end of one season to the start of the following season. DO NOT apply more than 4 Group 7 sprays per season.

The 2012/2013 edition of the AWRI publication, Agrochemicals Registered for use in Australian Viticulture 2012/2013 is available on-line. To access, visit the following link: https://www.awri.com.au/industry_support/viticulture/agrochemicals/agrochemical_booklet/.

This information is provided to inform the Australian grape and wine sector of agrochemical information, and should not be interpreted as an endorsement.

Technical Review: June 2012 issue now available online

12 June 2012 >

The June 2012 issue of Technical Review is now available for viewing online and for downloading. Access is available only to Australian winemakers and grapegrowers who pay the Wine Grapes or Grape Research levies.

To access the issue, click here.

Symposium to unlock latest smoke taint research

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Tainting of grapes from wildfire and controlled burns has cost the Australian wine industry more than $300 million over the past five years.
A free, one day symposium to be held in Melbourne this month will bring together Australia’s leading smoke taint researchers and collaborators to share the latest research and advice on managing and mitigating the impact of smoke taint.

The Australian Wine Research Institute (AWRI) Victorian Node Manager, Dr Mark Krstic said the 2012 Smoke Taint Symposium would present the latest research and developments to the wider wine grape industry.

“The impact of smoke taint on grape growers and wine producers is one of the biggest challenges facing our industry,” Dr Krstic said.
“This free event provides everyone in the industry, from grape growers and vignerons to public land managers, with the opportunity to discuss past and present findings and identify any gaps in knowledge or research.”

To be held on Wednesday, 20 June, the event is jointly run by the AWRI and the Victorian Department of Primary Industries. It is open to all within the Australian wine industry, the research community and those involved in controlled burn activities.

Dr Mark Downey, Director of the Victorian Government’s Centre for Expertise in Smoke Taint (CESTR), said the Symposium would also mark the official launch of the Victorian Node of the AWRI.

“The Victorian Node is a partnership between the AWRI, the Department of Primary Industries, the Grape and Wine Research and Development Corporation (GWRDC) and Wine Victoria and has been established to support grape growers and wineries in the Greater Victoria area,” Dr Downey said.

The 2012 Smoke Taint Symposium will be held at the Mercure Melbourne Treasury Gardens in Spring Street Melbourne from 10:00 am to 3:00 pm on Wednesday, 20 June.
Registration is free and those wanting to attend can RSVP via email to mark.krstic@awri.com.au for catering purposes.