• A method to quantify the relatively low levels of oxygen permeating through closures in wine bottles was developed. The assay uses a water-soluble compound to trap singlet oxygen and should allow us to estimate both oxygen permeation rates and the initial amount of oxygen in the headspace of a wine bottle within six to eight weeks.
• A red wine closure/storage study, which included screw caps with different air headspace volumes, has shown that there was no significant sensory difference, and only marginal differences in phenolic composition, between the natural cork-sealed wine and the wine bottled under screw cap with an intermediate headspace volume. The effect of a small headspace volume under screw cap was to enhance slightly a struck flint/rubbery 'reductive' aroma, while storage under a very large headspace volume conferred a slightly elevated oxidative character to the wine, which was evident at 12 months post-bottling.
• Studies of bentonite absorption in collaboration with the School of Chemical Engineering, The University of Adelaide, have indicated that there might be potential for enhanced adsorption, increased sustainability and reduced wine losses through the application of alternative contacting systems which are more efficient than the current batch method.
• An electronic library of UV/Vis spectra has been developed to assist identification of grape and wine phenolic compounds by routine HPLC analysis. More than 50 spectra of phenolic compounds and pigments commonly found in red wine have been added, including spectra of commercially available compounds, and reference standards that have been isolated or synthesised by the Tannin team such as malvidin-3-glucoside-6'-coumarate and Vitisin-B. Various approaches for the simple and efficient measurement of tannins by spectroscopic techniques have been assessed, a standard protocol for a prototype method is currently being developed and will be trialed in cooperation with Industry in the 2004/05 vintage.
• A number of polar grape skin pigments have been isolated by MLCCC and the mass spectrometric characterisation of the polar grape skin pigments has now been completed: ESI mass spectra have revealed that these pigments are anthocyanin oligomers and the presence of small amounts of such anthocyanin self-condensation products in grape skin and red wine has been demonstrated for the first time.
• A broad range of commercially available oenotannins, including grape-derived condensed tannins as well as hydrolysable tannins from oak and galls, has been sourced from Australian and overseas suppliers. The phenolic composition of these oenotannins has been profiled by HPLC analysis and, not unexpectedly, significant differences between the products have been observed. The oenotannins are subject to ongoing characterisation and serve as reference material for HPLC and spectroscopic measurements.
• The sensory assessment and analysis of phenolic compounds of red wine made in 2002 and 2003 by the Tannin team at the Hickinbotham Roseworthy Wine Science Laboratory has been completed. The data allowed us to robustly demonstrate the effects of yeast strains on red wine colour and pigment composition, and to characterise the mouth-feel effects caused by the addition of a particular grape-derived oenotannin.
• Work performed in collaboration with the School of Agriculture and Wine, The University of Adelaide through the CRC for Viticulture, has shown that fungal infection of grapes influences the protein content and extent of the potential protein instability problems of wine. Powdery mildew infection of grapevines increased protein content in Chardonnay juice and wine. In contrast, infection of Chardonnay or Semillon grapes by Botrytis cinerea in the vineyard resulted in decreased levels of proteins in the juice.
• A major study investigating consumer preference for a set of Riesling and Chardonnay wines was completed, which showed the diversity of consumer liking for these wine styles and provided data regarding the sensory properties of the wines that most influenced acceptance. Working with Provisor, the sensory analysis capacity available for AWRI research activities and also for wine industry clients has been substantially expanded.
• The compound responsible for a 'fungal must' taint evident in industry assessments of wine corks has been identified as 2-methoxy-3,5-dimethylpyrazine (MDMP). MDMP is an extremely potent compound with an unpleasant, musty, moldy aroma and an aroma detection threshold in a white wine of 2.1 ng/L. We have also prepared a deuterium-labelled analogue of MDMP and developed a stable isotope dilution assay for measuring MDMP in wines and cork extracts. Whilst the contribution of MDMP to the frequency and intensity of cork taint in bottled wine has yet to be established, it has been assessed by some wine industry personnel as second only to TCA as a cause of cork taint in Australian wine.
• Several grape and wine components have been identified as precursors to 2,3,6-trimethylphenylbutadiene (TPB) which has been identified by us as a new wine flavour compound derived from grape glycoconjugates. Informal sensory assessment of TPB indicated that it gave complex 'bottle aged' aromas to white wines. A new stable isotope dilution assay for TPB has been developed and used to analyses more than 100 wines. TPB was found at concentrations above threshold in older, compared to younger, wines. It was found mainly in Semillon and, to a lesser extent, in Chardonnay wines.
• Two isomeric glucosidic precursors to damascenone, have been synthesised and their conversion to damascenone studied. Both are converted to damascenone rapidly and in high yield at wine pH and room temperature. The formation of damascenone from these glucosides is slower than from the corresponding aglycons, but takes only a few days.
• A novel method, which can quantify 11 important volatile sulfur compounds in a single gas chromatography-atomic emission detection (GC-AED) run has been developed. The method is rapid, accurate and precise, and gives levels of detection 1-2 orders of magnitude better than published methods.
• AWRI Honours student, Julia Crossman, was awarded the Flinders University Medal.
• The paper entitled 'Screening for potential pigments derived from anthocyanins in red wine using nanoelectrospray tandem mass spectrometry' by Yoji Hayasaka and Robert Asenstorfer was one of the most cited papers published in the Journal of Agriculture and Food Chemistry in 2002.
• The new ThermoFinnigan LCQ Deca XP Plus mass spectrometer with Surveyor HPLC Pump, PDA detector and autosampler was purchased by Provisor and installed at the Waite Campus Mass Spectrometry Facility, within the AWRI, on 13 November 2003.
• A study on the effect of sample preparation methods and storage (frozen for up to 12 months) on the laboratory assays for total soluble solids, pH and the concentrations of total anthocyanins, and total phenolics in red grapes was completed and published, thus providing industry with simple laboratory protocols supported by sound objective validation data.
• A proposed industry 'standard' laboratory method for the measurement of the concentration of total anthocyanins in red grapes was prepared.
• Continuing investigations into alternative sample presentation modes for NIR scanning confirmed the feasibility of whole fruit analysis, offering the potential to speed up greatly the testing of red grapes by such techniques.
• The NIR team commenced the development of training and teaching of the principles and use of multivariate analysis techniques (chemometrics) to other AWRI staff members as well as for industrial and external research partners.
• Improved calibrations for the FOSS WineScan were developed by the inclusion of Australian wine samples to enhance the calibrations based on European wines that are provided with the instrument. This will be of assistance to Australian producers who have a core need for such technology, in-house.
• Optimising the Yeast Assimilable Nitrogen (YAN) content of grape juice to promote fermentation conditions which enhance the production of wine with a clean, fruity aroma profile has been demonstrated by undertaking a sensory study of wines made from a Chardonnay juice supplemented with different amounts of ammonium ions. Investigations are continuing with different yeast strains and fermentation conditions to define better the optimal range of juice YAN content.
• The first data to indicate that three yeast strains characterised by micro-scale vinification (1 kg) can similarly affect the colour properties of unoaked red wines of, at least, up to eight months of age, made on a pilot winery scale, have been obtained from a red wine fermentation trial conducted in the Hickinbotham Roseworthy Wine Science Laboratory during 2003 by the Lallemand-AWRI Wine Microbiology team collaboration. The micro-scale vinification methodology, which is being used to study the impact of other fermentation parameters on wine colour properties, could expedite optimisation of red wine fermentation.
• Intervention strategies for overcoming sluggish fermentation in a difficult-to-ferment Chardonnay, inoculated with a non-conventional Saccharomyces bayanus yeast strain, were found not to further detrimentally affect wine aroma by sensory assessment and chemical analysis. This finding suggests that the winemaker has flexibility in the choice of intervention strategies, which, in this work, included (i) sequential inoculation with Saccharomyces cerevisiae AWRI 838 at approximately the half-way point of fermentation, (ii) aerobic handling (pump over and 'splash') when fermentation slowed, or (iii) sequential inoculation with S. bayanus AWRI 1375 when fermentation had stopped.
• Sensory assessment of red wine in which the basic organic acid composition of post-MLF wine had been restored to pre-MLF conditions has provided the first objective evidence that MLF can modify red wine palate or mouth-feel, independent of the pH and titratable acidity. Work in progress to establish the chemical nature of the MLF-induced palate change, might provide a strategy for enhancing the effect.
• Data sourced from the AWRI Analytical Service commercial database confirmed that downward trends in mean volatile acidity and bound SO₂ concentrations in Australian wines have continued, coincident with strategies to improve these measures implemented across a range of Industry Services' projects.
• A record number of ten Trouble free winemaking - causes and prevention of common wine instabilities workshops were presented, in three states.
• Data sourced from an Industry Services' targeted survey confirmed that the mean concentration of the Dekkera/Brettanomyces yeast-derived compound, 4-ethylphenol, has continued to decline in Cabernet Sauvignon-based wines sourced from five regions. This is coincident with the implementation of strategies developed under the AWRI 'Brettanomyces project' that were aimed at assisting wine producers to make wine wines with lower concentrations of this compound than previously.
• It was demonstrated there is a large genetic diversity between isolates of Dekkera/Brettanomyces yeast from Australian red wines, and apparent large differences in the SO₂ tolerance between genetically similar groups of these isolates.
• The viticulturist responded to 430 enquiries. The majority (76%) were regarding the use of agrochemicals for pest and disease control, the persistence of residues through winemaking and their effects on fermentation, and issues related to maximum residue limits in overseas markets.
• Eleven thousand copies of the AWRI's annual publication, Agrochemicals registered for use in Australian viticulture 2003/2004 were produced and duplicated on the Institute's website. The booklet was distributed with the Australian Grapegrower and Winemaker, Technical Review and in the Research to Practice™ IPM and Spray application manuals. The tables were featured in Australian Viticulture and The Grapevine Management Guide 2003/2004 (Somers et al., 2003).
• The Viticulturist and Jelka Software developed an agrochemical database. This database is similar to the currently existing MRL database except that it contains all the information related to and presented in the publication, Agrochemicals registered for use in Australian viticulture 2003/2004. The ultimate aim is to provide a searchable database to replace the static retrieval of agrochemical information currently available from the AWRI's agrochemical website.
• A common spray diary format was developed in conjunction with industry for the 2004/2005 season and was placed on the AWRI website. Along with this format are explanations of the spray diary terminology and other relevant information.
• Staff of the John Fornachon Memorial Library responded to 3,788 requests for information during 2003/2004.
• Over 4,000 new records were added to the web-accessible database of the Library (available only to Australian winemakers and grapegrowers) during the year, making a total of over 29,500 records available for searching, 24 hours per day, 7 days per week.
• AWRI published 42 papers on AWRI activities in refereed and non-refereed publications.
• AWRI staff members gave 137 oral presentations, conducted 12 workshops (including 28 presentations within 10 Trouble free winemaking – causes and prevention of common wine instabilities workshops presented in three states) and presented 13 posters.
• AWRI staff members presented 46 lectures and coordinated a six week subject to undergraduate students.
• AWRI staff members supervised/co-supervised 21 postgraduate students.
• AWRI staff members recorded and responded to 6,979 requests for information during the 2003/2004 year or, to put the statistics into perspective, 28 people contacted the AWRI seeking information on every working day of the year. This figure does not include the amount of problem samples investigated (1,262) or the request for work through the Analytical Service which conducted >56,000 individual analyses during 2003/2004.

Readers are strongly encouraged to read the Institute's 2004 Annual Report (highlights of the year) in detail rather than relying on the dot points above for information.