Nominations open for AWRI Board positions

Levy Payers in the small (<2,000 tonnes), medium (2,001-50,000 tonnes) and large (50,001+ tonnes) producer categories are called on to nominate suitably qualified candidates for the vacant positions. This is an excellent opportunity for an interested candidate to become involved in the Australian wine industry’s own R&D organisation and, in addition to their other duties and responsibilities, provide a ‘coalface’ perspective to the direction and priorities of the AWRI’s research, development, extension and commercialisation activities.

In the event that more than one nomination is received for a particular category, an election will be held. Levy Payers in that particular category will have the opportunity to vote for their preferred candidate. If an election is necessary, it will be held in August/September 2017 and further information will be published at the time. Successful candidates will take office on 1 January 2018 for a term of three years.

The search for robust Australian malolactic bacteria strains – 2017 vintage trials

Entwine launching 2017/18 membership

This month Entwine membership renewals for 2017/18 opened online. All members are encouraged to log on to the Entwine registration page to submit their data and complete the renewal process. Membership fees have remained at $110 for vineyard and winery members. If you would like to become a member of Entwine, you can sign up here. You can also discover which companies are Entwine members across Australia by visiting the Entwine Australia member register.

This year, new for winery members of Entwine, is an online self-assessment survey of winery practices. The survey is compulsory for Members to demonstrate their ongoing participation in an approved certification program; however, Associate and Certified members are also encouraged to work through the survey. All survey respondents will receive a full report benchmarked against other winery members, later in the year.

Entwine has been embedded in the AWRI regional workshops which have been on the road in recent months. Entwine and regional datasets were recently presented in the Barossa, Langhorne Creek, Mornington Peninsula, Gippsland, Yarra Valley, Mt Barker, Pemberton, Margaret River and the Swan Valley. In addition to these, Mardi Longbottom was invited to speak to key influencers from across NSW about Entwine with a focus on the value of sustainability credentials to individual businesses, at the regional scale, and nationally. This presentation generated significant discussion especially from many in the group who had not seen the changes to Entwine in the past two years. Feedback received since the event has been very positive, with new and lapsed members signing up to the program.

To find out more about what’s new with Entwine, contact the AWRI helpdesk on mailto:helpdesk@awri.com.auor 08 8313 6600.

Brewing analyses coming soon

AWACs – two completed in June, one to come in November

Two Advanced Wine Assessment Courses (AWACs) were held at the AWRI in June with 32 participants successfully completing the course. Over the two weeks, more than 10,000 glasses were set, poured, tasted and washed. Each participant smelled, swirled and tasted over 300 wines, with all scores and comments recorded using the AWRI’s electronic scoring software ShowRunner. The next AWAC course will be held in Adelaide from 20 to 23 November 2017. If you haven’t registered your interest and experience details now is the time to do so! Find all the course details and complete your registration of interest on the AWAC webpage or contact events@awri.com.au.

Science week event reveals secrets of wine colour

Order the latest AWRI staff publications online

Accessing the latest AWRI publications is easy. Visit the AWRI Publications web page to:

• View the 10 most recent AWRI staff publications and order the articles online from the AWRI Library
• Search the staff publications database
• Read the full-text of ‘Technical Notes’ from Technical Review (PDF format)
• Read the full-text of ‘AWRI reports’ published in Wine & Viticulture Journal (PDF format).

A list of AWRI publications published since the last eNews is included below:

1915 Williamson, P.O., Francis, L., Mueller-Loose, S., Lockshin, L. Predicting wine repurchase: a case of low-retest reliability in China. Int. J. Market Res. Doi: 10.2501/IJMR-021: 19 p.; 2017.

1916 Essling, M. Ask the AWRI: Why was there more powdery mildew than usual this season? Aust. N.Z. Grapegrower Winemaker (640): 30-31; 2017.

1917 Albertin, W., Avramova, M., Cibrario, A., Ballestra, P., Dols-Lafargue, M., Curtin, C., Masneuf-Pomarède, I. [Brettanomyces bruxellensis: genetic diversity and sensitivity to sulfites] Brettanomyces bruxellensis: diversité génétique et sensibilité aux sulfites. Rev. Oenol. (163): 31-33; 2017.

1918 Rinaldo, A., Wilkes, E. The dark side of wine microbiology. WBM (March/April): 56-57; 2017.

1919 Gawel, R., Smith, P.A., Cicerale, S., Keast, R. The mouthfeel of white wine. Crit.Rev. Food Sci. Nutr. doi:10.1080/10408398.2017.1346584: 1-69; 2017.

Acknowledgement

The AWRI acknowledges support from Australia’s grapegrowers and winemakers through their investment body, Wine Australia, with matching funds from the Australian Government. The AWRI is a member of the Wine Innovation Cluster in Adelaide, South Australia.

Cool vintage means higher malic acid levels

The pH increase post-MLF will be higher than usual due to the higher starting levels of malic acid. Theoretically, each gram per litre (g/L) of malic acid contributes 1.12 g/L to the TA expressed in terms of tartaric acid. If all of the malic acid is converted to lactic acid, the TA (expressed as tartaric acid) will drop by 0.56 g/L for each g/L of malic acid that was originally present in the wine. For example, if a wine starts with 4 g/L of malic acid, the TA would be expected to drop by 2.24 g/L and the pH could increase approximately 0.2 after MLF.

Using magnetic nanoparticles for protein stabilisation

Bentonite fining to remove haze-forming proteins is a key step in the production of white and rosé wines, but has some drawbacks including wine losses and waste disposal issues. A new separation technology is showing potential as a bentonite alternative.

The technique uses magnetic nanoparticles – nanometre-scale particles that can be moved around using magnetic fields. Different coatings can be placed on these particles that allow them to bind to different compounds. In a recently published AWRI study, a coating designed to specifically bind haze-forming wine proteins was used. The coated particles were placed in heat-unstable wine, where the proteins bound to the nanoparticles’ surfaces. The particles were then able to be removed from the wine using a magnet.

Testing of the wine following the treatment found that the haze-forming proteins were removed, even from wines with very high protein content. Other components, such as wine phenolics, were unaffected. This technique therefore has potential to be used in the wine industry as an alternative to bentonite fining or could find applications in other areas such as water treatment or biotechnology.

The full paper detailing these results is accessible via the AWRI library: Mierczynska-Vasilev, A., Boyer, P., Vasilev, K., Smith, P.A. A novel technology for the rapid, selective, magnetic removal of pathogenesis-related proteins from wines. Food Chem. 232: 508-514.; 2017.

Upcoming events

In late May/early June there will be two Advanced Wine Assessment Courses and a wine show judging course to develop tasters’ wine judging skills. Both AWACs are full; however, there are still spaces left for the Wine show judging – an insider’s view of panel tastings course to be held on Friday, 9 June. This is a unique opportunity for participants to hone their wine judging skills under Australian wine show conditions, with guidance from some of Australia’s top wine show chairs.

On Thursday, 29 June Olaf Schelezki from the University of Adelaide will present a webinar entitled ‘Pre-fermentative addition of water or low alcohol wine into juice to manage alcohol levels of red wine’. Register here to attend.

The online AWRI events calendar and the Grape and wine events calendar are being continually updated – so please check back regularly to keep in touch with events in your region or contact the events team on events@awri.com.au or 08 8313 6600 if you have any queries.

Unlocking wine flavour during tasting

A long persistent palate is a hallmark of high quality wine and recent research may have identified the wine compounds responsible for this characteristic. The work showed that glycosides present in wine can break down in the mouth when a wine is tasted, contributing to lingering fruity or floral flavour. A glycoside consists of a flavour molecule bound to a sugar molecule that renders it flavourless. Previously, glycosides had been thought not to contribute to wine flavour, as it was believed they needed the action of fermentation enzymes or slow chemical reactions during ageing to break them apart and release the flavour molecule.

Sensory panellists tasted samples of glycosides from white wines and analysis showed that bacterial enzymes in saliva could unlock the bound flavour compounds in the glycosides, releasing a wave of flavour that continued after the wine was swallowed.

The amount of these glycosides in a wine could perhaps be used by winemakers as a quality marker, indicating the potential for a wine to have a long palate. The full paper detailing these results is accessible via the AWRI library: Parker, M., Black, C.A., Barker, A., Pearson, W., Hayasaka, Y., and Francis, I.L. 2017. The contribution of wine-derived monoterpene glycosides to retronasal odour during tasting. Food Chem. 232, 413-424.

ShowRunner – all-in-one wine show management software

The online entry module allows exhibitors to enter details of their wines once and then enter across multiple shows. Entry fees can also be paid online. Show organisers can monitor entries in preparation for judging and judges use iPads to enter their scores and comments. The results are generated instantly. To find out more about ShowRunner or to organise a demonstration, contact Francesca Blefari or Con Simos on events@awri.com.auor phone 08 8313 6600.

Past and future of grape crushing

Crushing is in important step in the production of most red wines. Classically, this process was performed by foot treading but the process started to be mechanised in the early 19^th century. Since then, a range of crushing equipment has been used, with relatively gentle overlapping lobe roller crushers the most common today. Lately there has been some renewed interest in different and more intense crushing equipment because of the potential for enhanced colour extraction or reduced skin contact time. A recently published article on the evolution and future directions for crushing equipment is now available from the AWRI website.

Call for submissions on wine processing aids

Food Standards Australia New Zealand (FSANZ) recently called for submissions on an application to permit the use of four new processing aids in wine. The processing aids—chitin-glucan, PVI/PVP co-polymers, ammonium hydrogen sulfite and silver chloride—are already permitted for use in the European Union. More information about the application can be found on the FSANZ website. The closing date for submissions is 6pm (Canberra time) 7 June 2017.

Order the latest AWRI staff publications online

Accessing the latest AWRI publications is easy. Visit the AWRI Publications web page to:

• View the 10 most recent AWRI staff publications and order the articles online from the AWRI Library
• Search the staff publications database
• Read the full-text of ‘Technical Notes’ from Technical Review (PDF format)
• Read the full-text of ‘AWRI reports’ published in Wine & Viticulture Journal (PDF format).

A full list of AWRI publications published since the last eNews is included below:

1901 Hayasaka, Y., Black, C.A., Hack, J., Smith, P. Structural characterization of reaction products of caftaric acid and bisulfite present in a commercial wine using high resolution mass spectrometric and nuclear magnetic resonance techniques. Food Chem. 230: 99-107; 2017.

1902 Corsi, A.M., Cohen, J., Lockshin, L., Williamson, P. Testing lexical equivalences for wine flavours in emerging markets: do hawthorns taste like blackberries? Food Qual. Pref. doi: 10.1016/j.foodqual.2017.03.011: 28 p.; 2017.

1903 Holdstock, M. Ask the AWRI: Taints in wine. Aust. N.Z. Grapegrower Winemaker (638): p. 64; 2017.

1904 Mierczynska-Vasilev, A., Boyer, P., Vasilev, K., Smith, P.A. A novel technology for the rapid, selective, magnetic removal of pathogenesis-related proteins from wines. Food Chem. 232: 508-514.; 2017.

1905 Parker, M., Black, C.A., Barker, A., Pearson, W., Hayasaka, Y., Francis, I.L. The contribution of wine-derived monoterpene glycosides to retronasal odour during tasting. Food Chem. 232: 413-424; 2017.

1906 Nguyen, T.T., Barber, A.R., Smith, P., Luo, X., Zhang, W. Application and optimization of the highly efficient and environmentally-friendly microwave-intensified lactic acid demineralization of deproteinized Rock lobster shells (Jasus edwardsii) for chitin production. Food Bioprod. Process. 102: 367-374; 2017.

1907 Capello, M.S., Zapparoli, G., Logrieco, A., Bartowski, E.J. Linking wine lactic acid bacterial diversity with wine aroma and flavour. Int. J. Food Microbiol. 243: 16-27; 2017.

1908 Varela, C., Barker, A., Tran, T., Borneman, A., Curtin, C. Sensory profile and volatile aroma composition of reduced alcohol Merlot wines fermented with Metschnikowia pulcherrima and Saccharomyces uvarum. Int. J. Food Microbiol. 252: 1-9; 2017.

1909 Ristic, R., van der Hulst, L., Capone, D.L., Wilkinson, K.L. Impact of bottle aging on smoke tainted wines from different grape cultivars. J. Agric. Food Chem. doi: 10.1021/acs.jafc.7b01233: 27 p.; 2017.

1910 Nordestgaard, S. Gentle or intense grape crushing? Aust. N.Z. Grapegrower Winemaker (639): 77-82; 2017.

1911 Cowey, G. Ask the AWRI: Adding water to high sugar must. Aust. N.Z. Grapegrower Winemaker (639): 88-89; 2017.

1912 Longbottom, M. Fellows of the ASVO. Wine Vitic. J. 32(2): p. 10; 2017.

1913 Bindon, K., Smith, P., Schulkin, A., Dambergs, B., Kassara, S., Barter, S., Solomon, M., Cynkar, W., Capone, D., McRae, J., Francis, L., Robinson, E., Johnson, D. Exploring the potential for grape objective measures to predict wine grade and style. Wine Vitic. J. 32(2): 46-47; 2017.

1914 Dry, P. Durif. Wine Vitic. J. 32(2): p. 55; 2017.

Acknowledgement

The AWRI acknowledges support from Australia’s grapegrowers and winemakers through their investment body, Wine Australia, with matching funds from the Australian Government. The AWRI is a member of the Wine Innovation Cluster in Adelaide, South Australia.