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The appliance of science

Published:  23 July, 2008

In the wine world, Australia punches above its weight. Consider the facts: in terms of production statistics, Australia isn't really a big player on the global wine scene. While 160,000 hectares (ha) under vine may sound a lot, compare this with the Languedoc's 250,000ha, or even Sicily's 200,000ha, and it's somewhat surprising that the Aussies have a reputation as one of the giants of the wine world. What is the secret to their success? It's likely to be down to several factors, but one of the key elements seems to be that, relative to the size of its industry, Australia has a very active wine-science community working on relevant, industry-driven projects, and its winemakers have gone on to apply the fruits of this research in the pursuit of quality.

Phil Laffer, the Orlando Wyndham winemaker responsible for mega-brand Jacob's Creek, claims that the application of wine science is the single most important thing' contributing to the success of the Australian wine industry. In the early days, the emphasis was on oenological research,' he explains, which was largely to do with the problems of making quality wine in warm climates. Over the past 20 years, the emphasis has changed towards viticulture.' Figures quoted by Laffer show how seriously the Australian wine industry takes research. In 2005, the industry invested A$28 million of our money in oenological and viticultural research,' he reveals - a figure that climbs to A$80 million once government contributions are added. Laffer points out that Australia does 15% of the world's wine research but accounts for only 5% of global production.

Brian Croser, one of Australia's most prominent wine scientists, gives a rather fuller historical perspective of the role of applied science in the Australian industry. There are three defined ages of scientific contribution,' explains Croser. The pioneer vignerons of the 19th century - Busby, de Castella and Kelly - were great empiricists and borrowed from the European repertoire of scientific knowledge. They were great observers, recorders and practical adapters to the Australian conditions of the varieties and methods they brought back from Europe.' After this initial contribution, Croser reckons that during the first third of the 20th century, which was the era of fortified wine, science made little contribution, until bacterial disease became epidemic. The late 1930s through until the 1960s was the period in which the fundamental issues of pH, sulphur dioxide (SO2) and hygiene were elucidated by Perkins, Hickinbotham and Fornachon. The University of Adelaide played a big part in this, and the result was the formation of the Roseworthy Oenology Diploma course and the Australian Wine Research Institute.'

Croser continues: The '60s began the table-wine era. The commitment of the family wine companies to the education

and research processes was religious, and the quality-control methodology, which still serves the commodity wine-production business so well, was developed.' Croser highlights the control of oxidation and wine stabilisation, as well as work with yeasts and malolactic bacteria, as winemaking processes advanced in Australia through the research and educational work supported by the companies. The next phase was the viticultural era, which continues to this day. Site selection, clonal selection, canopy management, irrigation manipulation and fruit sampling all contributed to the cost reduction and quality improvement of Australian commodity grapes.' Croser points out, though, that not all viticultural progress' has been beneficial, and that

the adoption of mechanical and minimal pruning has caused lasting problems in many regions. He also adds that compensating for the negative quality effects of mechanical harvesting has become an art form in Australia'.

Wine research

So just how is wine research done in Australia? Uniquely, the Australian wine industry has its own dedicated research and extension facility, the Australian Wine Research Industry (AWRI), which celebrated its 50th birthday in 2005. When it was founded, in 1955, the Aussies made almost exclusively fortified wine, and not all that much of it (88.6 million litres, from 170 producers, of which just over a third of a million litres was exported). By 2004, 2,000 producers were making a billion litres, and these days just over half of production is exported. In this time, the AWRI has grown over tenfold in size, and it is currently on a high, with some recent successes adding to its status as one of the world's premier wine-research institutes.

It relies heavily on money from the Grape and Wine Research Development Corporation (GWRDC), a government body whose mission is to support the development of the Australian wine industry by planning and funding collective research-and-development programmes, and then facilitating the dissemination, adoption and commercialisation of the results throughout the industry. The GWRDC itself does not do research; rather, it purchases it from providers such as universities, the CSIRO and the AWRI (its major provider). The GWRDC funding comes from levies on the annual grape harvest, with a few dollars payable for each ton (this made up A$9.68 million in 2004/05), with the Australian government providing matching funds.

The AWRI nets about a third of these levy monies, gaining additional income from its own analytical and contract services, plus some from the Cooperative Research Council for Viticulture (CRCV).

Recent AWRI projects have been extremely successful, and four that are worth highlighting in particular are those on closures, Brettanomyces, oxygen and tannins. The closures debate was rescued from empty rhetoric and the dead end of anecdotal observation and entrenched biases by the AWRI's hugely successful closure study. This began in 1999 and involved bottling a large number of bottles of the same wine - a Semillon from the Clare Valley - under a range of different closure types and then doing chemical and sensory analysis over time. Chief observations from this study have been that: (1) wines sealed with different closures look quite different as early as six months after bottling; (2) these differences are explainable by the different oxygen transmission rates of the various closure types; (3) synthetic corks allow a higher rate of oxygen transfer than natural corks, and metal-lined screwcaps provide the tightest seal of all; and (4) in some cases, the super-tight seal of tin-lined screwcaps can cause problems with rubber/struck-flint, sulphur-like odours that have a nasty habit of developing in low redox environments.

With its careful planning, its combination of up-to-date sensory and analytical work, and its rigorous statistical approach, this closure study has been a model for those who have tried to follow it. Still more work is needed on closure performance, but the AWRI has set the standard and focused attention on the vitally important subject of post-bottling wine chemistry.

If you knew Brett like I know Brett

Brettanomyces, a spoilage yeast that is commonly found in red wines, has also been the subject of an AWRI research programme that began in 2003. A forerunner of this project was a control strategy developed by the Industry Services team, helping to raise awareness of the risk factors for Brettanomyces, which has been running since 1999. This is one example where the contributions made by wine-science effort are measurable. When it is present at high enough levels, Brettanomyces, more common than most people realise, produces a negative sensory impact on wines. This is the result of a suite of compounds, with the principal culprits being the volatile phenols 4-ethylphenol and 4-eythlguiaicol, and isovaleric acid. The AWRI has carried out a survey on 4-ethylphenol in Cabernet- and Merlot-based wines from premium wine regions, demonstrating a gradual but steady decline in average concentrations from over 1,200 micrograms per litre (g/l) in 1997 vintage wines to just over 400g/l in 2002. The sensory threshold for this compound depends on the wine in question but is commonly cited as 425g/l. One of the key preventive measures in the fight against Brettanomyces has been improved use of sulphur dioxide (SO2). Data show that over the past several years, while the total SO2 levels in Australian wines have reduced or stayed the same, the all-important ratio of free:total SO2 has improved substantially, with corresponding higher levels of active free SO2.

More than just research

The tannin project is still ongoing, but it has shed some important new light on this vital aspect of red-wine chemistry, challenging some of the received wisdom in this area. It is aiming at the development of analytical methods for the quantification of tannins, and some progress towards this goal has already been made. The research programme on oxygen has just resulted in an important new publication, and includes the development of a colorimetric assay for oxygen ingress through closures.

But it would be wrong to focus solely on the research process itself. It's all very well doing research, but unless it is implemented effectively by wine growers, it's going to make little visible contribution to the industry. This is where the all-important extension arm comes into play. The application of wine science does require continual dissemination of the information by educational and research organisations,' says wine scientist John Casey. In the absence of a strong traditional culture of winemaking, the inputs of tertiary training and extension work have been vital to the Australian wine industry. That is, application of the existing body of knowledge is more important in the medium term than the fruits of [current] research.' He's got a point. There's no sense in doing research if it's not relevant to what winemakers are doing and if it doesn't get to them in a form that they can appropriate, understand and put into practice. And there's plenty already known that, if applied correctly, will enhance wine quality significantly. Another well-known Australian wine scientist, Richard Gibson, echoes this sentiment. Australia thinks it spends too little on wine research, but every dollar goes into relevant stuff - no long-winded projects seeking to elucidate the factors that create typicity in the lower Hunter region, for example,' he points out. The relationship between researchers/academics and industry is excellent, unlike in places such as Italy. The goals are clearly set, and everyone works towards them, not on private agendas.' Indeed, one of the strengths of the AWRI is that it combines its research with its extension work, and also the work of its analytical services, in a seamless fashion.

But Brian Croser has a slightly different perspective on this issue. He reckons that the Aussie wine industry's commitment to research has been worthwhile aside from any benefits it has afforded, because of the spin-off benefit to the industry's reputation. Investment in research and education has moulded the culture of practical achievement that underpins Australian wine success and has put Australian wine quality in the global spotlight,' he explains. The research endeavour is a sufficient contributor of itself even without applicable outcomes, and the Australian wine industry would be a much-diminished entity without its contribution.' Croser adds that Australia has received disproportionate recognition for the employment of cutting-edge technology derived from its scientific research programmes. This has global commercial consequences, increasing the respect for Australian wine and its technologists. Perception has had at least equal effect on the economics of the industry as the reality of scientific achievement.'

Looking forward

What of the future? Perhaps the biggest gap in wine-science knowledge is understanding the mechanistic links between what is in the grapes and the quality of the wine, and how what is in the grapes can be usefully manipulated by vineyard management and planting decisions. A greater understanding of this would enable winemakers to get more out of their vineyards, and, perhaps more excitingly, it would enable the identification of new distinguished sites' or terroirs for the production of high-quality wines. Planting a vineyard is a risky, capital-intensive venture, and it's difficult to justify planting in a new region if all you have is homoclime analysis (a rather blunt matching of averaged climatic data) together with a look-see, back-hoe, pit-soil analysis and very little actual knowledge of the link between soils, climate and grape correlates of wine quality. Indeed, one of the ongoing AWRI projects aims to identify grape precursors of wine quality. If this is achieved, then the next logical step

would be to understand how vineyard interventions can enhance positive grape-flavour precursors and minimise negative ones. The viticultural holy grail of understanding the mechanisms of terroir would then be in sight.

This leads us back to Brian Croser. He has some strong ideas about the future direction of the Australian wine industry, which he thinks should be the pursuit of what he calls the idea of quality'. His concept is that Australia has become well known in export markets for its commodity wine, while its fine-wine culture has been largely a local phenomenon, poorly understood and appreciated outside Australia. Because of this, he feels Australia has missed out on being part of the cutting edge of fine-wine development. Now is the time for investment in the "idea of quality",' says Croser. The simple hedonistic test of what is in the glass is not sufficient for the "idea of quality", and nor is it sufficient to satisfy the emerging fine-wine opportunity in the affluent, ageing Western world. The "idea of quality" for fine wine includes the intellectual consideration of why the wine tastes as it does.' This is the familiar Croser theme of the importance of distinguished sites. The story has to rigorously support the pedigree of quality, and that inevitably turns to place of origin or terroir.

Terroir exists, and Australia has some of the world's best. We urgently need to establish a "quality at any cost" project to research and elucidate our best terroirs and develop methods to maximise the quality from them. We need to understand the effects of our oceans on the climate and on the phenology of our vineyards. We need to understand the contribution of the geology and soil to the system of supply of water and nutrients in our best terroirs. We need to understand the combinations of rootstocks and clones and the planting regimes to maximise the quality from the best vineyards in Australia. We need to be at the forefront of selective mechanical harvesting and fruit sorting to match the most fastidious of hand picking. We need to understand the microflora of our vineyards and wineries and develop methods to reliably use those microorganisms that can contribute to quality and complexity.'

It sounds a tall order, but it may well be that Australia needs to apply itself to these wine-science research goals if it is to carry on punching above its weight in the increasingly competitive global wine industry and avoid disappearing down the cul-de-sac of ever-cheaper (and less profitable) commodity wine.