Wine & Viticulture Journal – AWRI Reports

A rose by any other name: novel wine yeast that impart floral aromas

Cordente, T., Solomon, M., Godden, P., Curtin, C., Johnson, D. A rose by any other name: novel wine yeast that impart floral aromas Wine & Viticulture Journal 31 (5), 39-40; 2016.

Abstract: While there is substantial variation amongst existing wine yeast strains in their capacity to influence wine style, some desirable flavour compounds are not produced at concentrations where they significantly impact wine style. As part of ongoing yeast strain development projects at the Australian Wine Research Institute, novel wine yeast that make ‘floral’/’rose’ aroma compounds have been generated.

Vintage 2016 – observations from the AWRI helpdesk

Coulter, A. Cowey, G., Petrie, P., Essling, M., Holdstock, M. Stockley, C., Simos, C. Johnson, D. Vintage 2016 – observations from the AWRI helpdesk Wine & Viticulture Journal 31 (4), 43-45; 2016.

Abstract: Since 1955 the AWRI has provided technical support to Australia’s grapegrowers and winemakers. The AWRI helpdesk responds to queries, conducts investigations and monitors technical trends across the nation’s wine regions, disseminating information via eBulletins, the AWRI website, webinars and face-to-face extension events. Vintage 2016 showed some similarities to vintage 2015, with an early and compressed harvest, rain close to harvest in certain areas and some concerns about bushfire smoke.

Wine yeast: Where are they from and where are we taking them?

Borneman, A., Herderich, M., Johnson, D. Wine yeast: Where are they from and where are we taking them? Wine & Viticulture Journal 31 (3), 47-49; 2016.

Abstract: Advances in DNA sequencing have allowed analysis of the genomes of large numbers of wine yeast strains for the first time. Results show that wine yeast have low genetic variation compared with the overall genetic diversity of the species Saccharomyces cerevisiae (which also encompasses brewing, baking, sake and palm wine yeasts). This new understanding will be harnessed in future yeast breeding programs.

In vino veritas – investigating technologies to fight wine fraud

Wilkes, E., Day, M., Herderich, M., Johnson, D. In vino veritas – investigating technologies to fight wine fraud Wine & Viticulture Journal 31 (2), 36-38; 2016.

Abstract: Many of the great wines of the world have been subject to claims of substitution or counterfeiting, damaging the reputation of the affected brands and countries of origin. This article describes recent work at the AWRI looking at analytical approaches to determine the origin of wine that could form an important part of global efforts to fight wine fraud.

Assessing the environmental credentials of Australian wine

Abbott, T., Longbottom, M., Wilkes, E., Johnson, D. Assessing the environmental credentials of Australian wine Wine & Viticulture Journal 31 (1), 35-37; 2016.

Abstract: Life cycle analysis (LCA) is a method for assessing the environmental impact of a product or process, taking into account all of the steps from ‘cradle to grave’. While LCA has been used to assess specific Australian wine products in the past, this is the first time the method has been used to examine the environmental impact of the Australian wine industry as a whole. An indicative carbon footprint of Australian wine was calculated and found to be relatively low, but the analysis also identified particular ‘hot spots’ where improvements could be realised.

Applying the latest understanding of grape composition

Smith, P., Schulkin, A., Kassara, S., Barter, S., Soloman, M., Cynkar, W., Capone, D., Francis, L., Bindon, K., Johnson, D. Applying the latest understanding of grape composition Wine & Viticulture Journal 30 (6), 33-38; 2015.

Abstract: A wide range of compounds that contribute to wine’s appearance, aroma, flavour and texture are derived from compounds present in grapes. Quite a lot is now known about these compounds, their origin, how to measure them and how to influence their concentration through viticultural and/or winemaking practices. This article describes how key grape-derived compounds influence wine and discusses a project that is applying the latest compositional knowledge to improve the objectivity of measures of grape quality and style.

Using copper more effectively in winemaking

Reschke, S., Tran, T., Bekker, M., Wilkes, E., Johnson, D. Using copper more effectively in winemaking Wine & Viticulture Journal 30 (5), 35-37; 2015.

Abstract: Winemakers commonly add copper to wines before packaging to remove unpleasant ‘reductive’ aromas. However, residual copper in wine can have negative consequences including unsightly deposits, increased risk of oxidation and the formation of further reductive compounds. This article reports a pilot study examining the effectiveness of making copper additions during fermentation and using the yeast present to bind up and remove the added copper from the final wine.

Vintage 2015 – observations from the AWRI helpdesk

Coulter, A., Cowey, G., Petrie, P., Essling, M., Holdstock, M., Stockley, C., Simos, C., Johnson, D. Vintage 2015 – observations from the AWRI helpdesk Wine & Viticulture Journal 30 (4), 34-37; 2015.

Abstract: The AWRI helpdesk provides technical support to Australia’s grapegrowers and winemakers and monitors technical trends across the nation’s wine regions. During vintage 2015, helpdesk enquiries were again dominated by issues related to weather events, in particular rain and bushfires. The helpdesk responds to individual queries on a confidential basis, but also provides the latest information to industry via eBulletins, the AWRI website, webinars and face-to-face extension events.

Unravelling the capricious nature of Oenococcus oeni

Borneman, A., Bartowsky, E., Costello, P., Sternes, P., Chambers, P., Herderich, M., Johnson, D. Unravelling the capricious nature of Oenococcus oeni Wine & Viticulture Journal 30 (3), 34-37; 2015.

Abstract: Exciting times lie ahead for malolactic fermentation (MLF) research and this will bring substantial benefits to winemakers. New genetic sequencing techniques are revealing the incredible diversity amongst strains of Oenococcus oeni, the bacterium primarily responsible for MLF. This new knowledge should provide extensive opportunities for Australian winemakers to choose MLF strains tailored to suit their individual conditions – optimising both fermentation efficiency and flavour release.

Microbiological stability of wine packaging in Australia and New Zealand

Tran, T., Wilkes, E., Johnson, D. Microbiological stability of wine packaging in Australia and New Zealand Wine & Viticulture Journal 30 (2), 46-49; 2015.

Abstract: One of the last processing steps that takes place before a wine reaches a consumer is the packaging process. Whether a wine goes into a cask, bottle or other vessel, the decisions and processes carried out at the point of packaging will have a significant impact on the characteristics of the wine when it is consumed. Ensuring that wines are free from microbes that can grow in the packaged product is one of the key considerations of the packaging process, and one of the more difficult to manage. This article presents knowledge gained through the conduct of microbiological audits of packaging processes across the Australian and New Zealand wine industries. It includes a brief overview of industry practices, some common misconceptions regarding the microbiology of bottling and an audit case study.

Applying spectral technology to improve winemaking efficiency

Godden, P., Scrimgeour, N., Wilkes, E., Cynkar, W., Johnson, D. Applying spectral technology to improve winemaking efficiency Wine & Viticulture Journal 30 (1), 28-32; 2015.

Abstract: Spectral technologies have been developed for the rapid and simultaneous analysis of sugar and colour levels in red grape homogenates, and of yeast assimilable nitrogen (YAN) and other compositional variables in white juice. The technologies have been extensively trialled in large wineries over several vintages, with useful data obtained in real time. This ongoing work demonstrates the significant potential of spectral analysis to replace many expensive and time-consuming traditional laboratory methods, providing winemakers with opportunities to optimise winemaking processes.

Exploring oxygen’s influence

Smith, P., Day, M., Schmidt, S., Bindon, K., Kassara, S., Schulkin, A., Kolouchova, R., Wilkes, E., Herderich, M., Johnson, D. Exploring oxygen’s influence Wine & Viticulture Journal 29 (6), 33-36; 2014.

Abstract: There are a number of unanswered questions about oxygen’s role in the winemaking process. How much oxygen gets into juice through production? What does juice exposure to oxygen do to final wine style and composition? What does oxygen exposure during fermentation do to wine style? Can oxygen be better measured during winemaking or markers for exposure be identified? This article presents results from the first stage of a research program at the AWRI investigating influences on wine style from management of oxygen during winemaking.

Staying a step ahead of ‘Brett’

Curtin, C., Borneman, A., Zeppel, R., Cordente, T., Robyn, K., Chambers, P., Herderich, M., Johnson, D. Staying a step ahead of ‘Brett’ Wine & Viticulture Journal 29 (5), 34-37; 2014.

Abstract: Brettanomyces bruxellensis (known in the wine industry as ‘Brett’) is a species of yeast that produces unpleasant medicinal and phenolic characters in wine. While there are practical steps to be taken in the winery that are currently successful at controlling ‘Brett’, there is a risk that a strain could emerge that is resistant to control strategies. For that reason, research is under way to understand this yeast at the genetic level and make sure winemakers can stay ahead of any ‘Brett’ threat.

Vintage 2014 – Trends from the AWRI helpdesk

Coulter, A., Cowey, G., Dry, P., Essling, M., Holdstock, M., Stockley, C., Simos, C., Johnson, D. Vintage 2014 – Trends from the AWRI helpdesk Wine & Viticulture Journal 29 (4), 34-36; 2014.

Abstract: The AWRI helpdesk provides technical support to Australia’s grapegrowers and winemakers and monitors technical trends across the nation’s wine regions. During vintage 2014, helpdesk enquiries were dominated by issues related to extreme weather events including frosts, heatwaves and bushfires. A regulatory issue concerning changes to the limits for copper, iron and manganese in wines exported to China also raised significant concern. The helpdesk responds to individual queries on a confidential basis, but also provides the latest information to industry via emails, the AWRI website, webinars and face-to-face extension events.

Influence of phenolics on white wine quality and style

Gawel, R., Godden, P., Williamson, P., Francis, L., Smith, P., Waters, L., Herderich, M., Johnson, D. Influence of phenolics on white wine quality and style Wine & Viticulture Journal 29 (3), 34-36; 2014.

Abstract: The importance of phenolic compounds in red wine colour and texture is well known. For white wines the story has not been as well understood. Texture in white wines is seen as positive, but coarseness and hardness are not. AWRI researchers have studied the effects of phenolics in commercial white wines, finding out about their effects on wine style, consumer liking and winemaker assessments.

Tannin: impacts and opportunities along the value chain

Smith, P., Bindon, K., McRae, J., Kassara, S., Johnson, D. Tannin: impacts and opportunities along the value chain Wine & Viticulture Journal 29 (2), 38-41; 2014.

Abstract: Studying tannins is challenging. Their behaviour is rarely predictable; results can be contradictory and experiments often seem to generate just as many questions as they answer. But if you step back and take a broader view of the tannin research conducted over the past few years, you can see that real progress has been made in understanding tannin at key points across the grape and wine value chain, with practical outcomes for growers and winemakers.

The role of trace metals in wine ‘reduction’

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

Abstract: Copper salts have traditionally been added to wines to remove unpleasant volatile sulfur aromas. However, investigations of interactions between metals and volatile sulfur compounds are now revealing that metals can also promote the formation and release of these unwanted aroma compounds, particularly in low oxygen storage environments. Winemakers can minimise the risk of ‘reductive’ aromas by managing the timing of any copper additions and taking steps to minimise metal concentrations.

Optimising fermentation through simulation

Muhalck, R., Scrimgeour, N., Wilkes, E., Godden, P., Johnson, D. Optimising fermentation through simulation Wine & Viticulture Journal 28 (6), 38-43; 2013.

Abstract: What if winemakers had advance warning of sluggish fermentation? What if winemakers could predict when a wayward ferment might arise and take steps to prevent it, before it happened? The AWRI Ferment Simulator is a powerful new weapon in the winemaker’s arsenal. lt can be used to predict ferment behaviour, test and evaluate alternative ferment management strategies, and monitor refrigeration and electricity demand so that corrective action can be taken on time and on target.

The DNA of innovation

Borneman, A., Herderich, M., Johnson, D. The DNA of innovation Wine & Viticulture Journal 28 (5), 52–56; 2013.

Abstract: Winemaking is arguably the world’s oldest biotechnology, with a history dating back more than 7000 years. The past century has seen unprecedented advances in wine research with the advent of genomics and DNA sequencing. These technologies stand to transform our understanding of wine yeast, boost efforts to combat pests, diseases and contaminants and provide greater insight into wine character, regionality and terroir. This AWRI Report explains how and why DNA sequencing technologies are relevant to grape and wine producers and outlines their potential for the future.

What’s in a label? How science is helping winemakers to respond to new EU rules concerning allergens in wine

Hoxey, L., Stockley, C., Wilkes, E., Johnson, D. What’s in a label? How science is helping winemakers to respond to new EU rules concerning allergens in wine Wine & Viticulture Journal 28 (4), 38-41; 2013.

Abstract: on 1 July 2012, new rules came into force regarding the labelling of potential allergens in wine exported to the European Union. The AWRI developed and validated a test for milk and egg residues to allow Australian producers to measure the levels of allergens in their wines and give consumers and policymakers continued confidence in Australian wine. Through national and international collaborations, work is also under way to ensure that testing is equally robust overseas.

Grape quality assessments: a survey of current practice

Longbottom, M., Simos, C., Krstic, M., Johnson, D. Grape quality assessments: a survey of current practice Wine & Viticulture Journal 28 (3), 33-37; 2013.

Abstract: There is room for improvement in winegrape assessment procedures according to a new survey, detailed in this report. With responses from grape and wine producers throughout Australia – with various roles in grape production, supply and purchase – the survey indicates that there is industry-wide support for a standardisation of assessment methods and procedures to ensure consistency, accuracy and transparency for all.

The science of texture

Gawel, R., Day, M., Schulkin, A., Smith, P., Herderich, M., Johnson, D. The science of texture. Wine & Viticulture Journal 28 (2), 30–34; 2013.

Abstract: Astringency, viscosity, oiliness, hotness and bitterness: these ‘textures’ influence white wine consumers and contribute to wine style. But what makes a wine ‘textural’? Phenolics, acidity and alcohol play important roles, but how? To find out, researchers at the AWRI measured their effect on white wine texture and analysed interactions between them. A major finding was that some phenolics reduce rather than increase astringency and hotness of white wine.

Seeing through the smoke

Parker, M., Baldock, G., Hayasaka, Y., Mayr, C., Williamson, P., Francis, I.L., Krstic, M., Herderich, M., Johnson, D. Seeing through smoke. Wine & Viticulture Journal 28 (1) : 42–46; 2013.

Abstract: As a result of bushfires and controlled burning, winemakers and grapegrowers are seeking more information about the effects of smoke on ripening grapes, wine composition and sensory qualities. What is the relationship between smoke taint and smoke exposure? How does smoke interact
with grape and vine development? Research at the AWRI has led to the development of strategies to identify smoke exposure and a deeper understanding of smoke taint. This new insight is being used to provide advice and assistance to grape and wine producers.

Beyond Bentonite

Robinson, E., Scrimgeour, N., Marangon, M., Muhlack, R., Smith, P., Godden, P., Johnson, D. Beyond Bentonite. Wine & Viticulture Journal 27 (6) : 20–26; 2012.

Abstract: Until now, bentonite treatment has been the winemaker’s best answer to troublesome haze-causing proteins. Breakthroughs in understanding the structure and properties of those proteins at the AWRI have led to the discovery of a potentially viable and practical alternative. Laboratory, pilot and industry scale trials of proctase have been successfully completed.

Aged Riesling and the development of TDN

Black, C. Francis, L. Henschke, P. Capone, D. Anderson, S. Day, M. Holt, H. Pearson, W. Herderich, M. Johnson, D. Aged Riesling and the development of TDN Wine & Viticulture Journal 27 (5) : 20–26; 2012.

Abstract: Understanding and managing aged Riesling flavour has proven to be both complex and elusive. Some older Riesling wines have been described as having an aroma of ‘kerosene’, while most winemakers will describe the wines as displaying toasty, lime/marmalade flavours. This AWRI report provides winemakers with the most up-to- date information and advice on the management of the TDN compound in aged Riesling.

Managing eucalyptus aromas

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

Abstract: As an investigative story, the hunt for what causes eucalyptus character – and the origin of its aroma compound 1,8-cineole – in wine has the makings of a classic ‘whodunnit’. The search for the ‘ culprit’ or ‘ally’, depending on your preference for or against eucalyptus characters, has thrown up false leads, and an unexpected ending. Studying the origin of 1,8-cineole, AWRI research found that the location and leaves of Eucalyptus trees play a direct role in the concentration of 1,8-cineole and occurrence of the ‘eucalypt’, ‘ fresh’ or ‘minty’ characters in wine.

Quality in a cool climate – maceration techniques in Pinot Noir production

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) : 18–26; 2012.

Abstract: Australia’s cool climate wines are gaining favour. At the 2011 Melbourne Wine Show a Tasmanian cool climate Shiraz won the Jimmy Watson Trophy, while in the past the Australian wine sector has built its reputation on ripe, robust, fruit-driven red wine styles. With higher production costs, cool climate viticulture can be challenging; consistent, high quality is essential for wines to be able to target higher price points in the market. This article explains how maceration techniques can influence the tannin and colour profiles of Pinot Noir, an important cool climate red wine varietal.

Ten years of transformation: Reflecting on the technical advances in the wine industry over the past decade

Godden, P. Johnson, D. Ten years of transformation: Reflecting on the technical advances in the wine industry over the past decade. Wine & Viticulture Journal 27 (2) : 24–26; 2012.

Abstract: With the current challenges faced by the Australian wine industry, it is easy to lose sight of the extraordinary technical advances that have been made in the last 10 years. Since 2002, many practices have changed markedly; from a technical perspective, there has been a transformation in how we do many things, with grapegrowers and wine producers working smarter and more efficiently. This article explores some of those changes, the science and technology behind them and the technical support necessary for that practice change to have occurred. Investments made in the AWRI and other agencies by grapegrowers and winemakers via their investment agency, the GWRDC, have been instrumental in the development of these game-changing processes.

Opportunities to improve winemaking profitability

O’Brien, V. Johnson, D. Opportunities to improve winemaking profitability. Wine & Viticulture Journal 27 (1) : 18–21; 2012.

Abstract: A team of process experts at The Australian Wine Research Institute is offering a paradigm shift for grape and wine producers competing in a crowded global market. The approach is highly practical and focussed on efficiency drawing on the team’s collective years of experience in technical winemaking and advanced manufacturing methods.