Didn’t see that coming – how did that get there?
Power generation from grape marc – soon to be a reality
Are consumer preferences constant?
Good things come in small packages: micro-scale fermentations at WIC Winemaking Services
Experienced chemist and well respected industry technician joins the AWRI
Read up on alternative grape and vine varieties
Calcium levels in wine are traditionally not something that you would be checking in juice or wine, but a number of wines investigated by the AWRI’s Winemaking and Extension Services (WES) team recently, containing crystals, in particular calcium tartrate crystals, would suggest otherwise.
Calcium levels in wine are typically low, or have they been creeping up in recent times? While calcium occurs naturally in grapes and wines, levels can be elevated by the use of calcium salts as additives or fining agents, such as deacidification with calcium carbonate, skim milk and calcium based bentonites. It has been suggested that there is a real risk of calcium tartrate precipitation when the level of calcium is over 60 mg/L in red wines and 80 mg/L or more in white wines (Ribereua et al. 1977). Further reading on calcium and CaT deposits can be found here. If you are not aware of the calcium levels in your wines, then you might not see this potential problem coming.
Wine producers in the Riverland could soon be using power generated from grape marc. The AWRI has been working on the feasibility of extracting bioenergy from grape marc for a number of years and, in 2009, the AWRI’s Dr Richard Muhlack won an Australian Government prize awarded by the Department of Agriculture, Fisheries and Forestry (DAFF) for his work in this area. Now, a grape marc bioenergy facility will be built.
Our aim has been to examine marc and grape stalks for their calorific value and combustibility under various conditions, in order to produce reliable data on which business cases for the implementation of this technology might be based. Recently, Tarac Technologies (a partner in our 2009 DAFF bio-energy project) together with Murrumbidgee Irrigation (MI), issued an invitation to tender for design and construction of a 10MWth grape marc bioenergy facility (estimated project cost > $10m) to be located in Griffith NSW. Coincidentally, Richard Muhlack re-located from Adelaide to Griffith in November 2010, in order to manage our newly-established AWRI Riverina Node. According to the tender invitation document, Tarac and MI intend to sell surplus (renewable) electricity to other local large energy users, which would inevitably include wine Riverina wine producers. This demonstrates great confidence in grape marc bioenergy technology, and we consider this is a big win; it de-risks the technology, and hopefully will provide necessary momentum for similar developments in other wine regions. For further information contact Richard Muhlack.
Can a person’s taste preferences be altered? Are likes and dislikes static, due to genetics or early upbringing and only changing over the long-term, or can they be influenced by recent wine experiences? We’ve shown that there can be a marked change in preference after different wine encounters, especially for newer wine consumers, and confirmed that opportunities to expose consumers to wines will affect their responses.
In two linked studies we have assessed short-term changes, either due to repeated experience with different wine types or due to a wine education course. While consumers can’t be persuaded to appreciate wines they previously disliked, many can have greater enjoyment of wines with higher fruit and oak flavour than they previously demonstrated.
After two weeks of exposure to different wines, consumers had increased liking scores of wines with similar characteristics to the wine they were exposed to, whether a more complex, higher flavoured style or a lighter and sweeter type.
In the second study, many consumers changed preferences after a tasting course towards wines with greater fruit intensity and away from wines with a degree of bitterness or stronger acidity.
For more information please contact Patricia Osidacz.
Need to run a micro-scale fermentation to test for agrochemical residue, or perhaps you want to check out how that single vine new variety might perform? Replicated trials can now be performed at WIC Winemaking Services, under the care of Gemma West, an experienced and qualified winemaker.
The WIC Winemaking Service can run a series of 5 kg-scale (for red and white fruit) replicated trials, using a variety of temperature controlled rooms which enable good results even with more hostile treatments such as those in agrochemical residue trials.
Trials can be designed to include high-end chemical or sensory analysis. The new micro-fermentation capability complements WIC Winemaking Services’ current offering of replicated small- and pilot-scale winemaking.
For further information, please contact Gemma West or on telephone (08) 8313 6600.
With his appointment to the AWRI as Research Manager – Industry Applications, Eric Wilkes is looking forward to working with wine producers around Australia to assist them to adopt beneficial technologies and practices.
Eric has worked in the beverage industry since completing his PhD in chemistry at the University of Newcastle in 1997, where he held both teaching and technical positions. Initially spending four years based in the Hunter Valley with the then independent Rosemount Estates he moved to SA in 2001 to take up the role of Group Chemist with the Foster’s Wine Group based at the Wolf Blass Winery. In 2007 he accepted the role of Global Manager Analytical Services with the Foster’s Group overseeing the integration and alignment of testing and technical services across their whole beverage portfolio on three continents; and in 2010 he joined P&N Beverages in Sydney as National Technical Manager with responsibility for new product development, product QA, customer feedback and product compliance. Specialising in technical management he has extensive experience in successfully integrating new technologies and systems into wine production and improving those already in place. He is also a past committee member of the Interwinery Analysis Group and the co-author of a book on wine laboratory analysis. Eric was already well known to many AWRI staff members who have worked with him on many collaborative projects over the years, and we have always been impressed by his wealth of knowledge and experience across many areas of expertise, not to mention his affable nature; which is why we recruited him! Eric has hit the ground running in his new role, and we are sure he will turbo-charge many of our Development projects.
A recent addition to the AWRI’s Research to Practice series is ‘Alternative varieties: emerging options for a changing environment’. The AWRI’s John Fornachon Memorial Library supports staff by sourcing references to aid their research. Some of the books on alternative grape and vine varieties, added to our book collection during the course of producing the Research to Practice handbook, are listed.
- Bettiga, L.J., Christensen, L.P., Dokoozlian, N.K., Golino, D.A., McGourty, G., Smith, R.J., Verdegaal, P.S., Walker, M.A., Wolpert, J.A., Weber, E. Wine grape varieties in California. iv, 188 p., 2003.
- Bohm, J., Gato, O., Laureano, P. The grapevine varieties from Alentejo. 17 p., 1999.
- Higgs, D. Emerging varietal wines of Australia : a guide for the adventurous winelover. ix, 209 p., 2005.
- Ministère de l’agriculture et de la pêche – CTPS. Catalogue des varietes et clones de vigne cultives en France [Catalogue of selected wine grape varieties and certified clones cultivated in France]. 455 p., 2007.
- Tassie, L. Dry, P. Essling, M. Alternative varieties: emerging options for a changing environment. xiv, 142 p., 2010.
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.