Using yeast to modulate wine flavour
Background
The flavour-active yeast research program is focused on understanding how the metabolism of yeast interacts with the wine production environment, and ultimately how this impacts upon wine sensory properties and relates to consumer preferences.
A core aspect of our work is the characterisation of known and novel flavour-active yeast genes. This is achieved through application of advanced molecular tools and collaboration with the AWRI Flavour Chemistry team. Availability of characterised genes enables us to develop prototype flavour-enhancing wine yeasts such as the thiol-releasing strain we have described recently. Non-genetic modification (GM) strategies can then be applied to develop industry-relevant wine yeast strains with these ‘benchmark’ properties.
Progress
Non-GM strategies have been used to develop novel yeast strains with the ability to ferment robustly, while producing minimal or non-detectable quantities of hydrogen sulfide. Two have been commercialised under the names Maurivin Distinction® and Maurivin Platinum®, with the former trialled in several wineries during the 2008 Australian vintage.
Research into the benefits of co-inoculation strategies has also contributed to the development of commercialised blended yeast products: Anchor Alchemy I® and Anchor Alchemy II®. Trials conducted during the 2007 vintage confirmed previous results, highlighting chemical and sensory differences in wines resulting from co-inoculation, as opposed to post-fermentation blending of single-strain wines. Consumer sensory trials demonstrated that consumers preferred the 2007 Sauvignon Blanc trial wine made using co-inoculation, compared to the single strains themselves.
Highlights
Commercialisation of
- Maurivin Distinction®
- Maurivin Platinum®
- Anchor Alchemy I®
- Anchor Alchemy II®
Images:
Figure 1. Fermentation-derived volatile compounds in Shiraz produced from low YAN (approx. 100 mg N/L) musts supplemented with different amounts of DAP. The coloured areas illustrate trends and the ranges of concentrations of volatiles measured in experimental wines made using different red wine yeasts and across two vintages (Source: AWRI Annual Report 2008, p. 16)
Project leader: Dr Paul Chambers
Project team members:
Publications:
973 Swiegers, J.H.; Pretorius, I.S. Modulation of volatile sulfur compounds by wine yeast. Appl. Biochem. Microbiol. 74(5): 954–960; 2007 (click here to order).
997 Swiegers, J.H.; Capone, D.L.; Pardon, K.H.; Elsey, G.M.; Sefton, M.A.; Francis, I.L.; Pretorius, I.S. Engineering volatile thiol release in Saccharomyces cerevisiae for improved wine aroma. Yeast 24: 561–574; 2007 (click here to order).
854 Swiegers, J.H.; Bartowsky, E.J.; Henschke, P.A.; Pretorius, I.S. Yeast and bacterial modulation of wine aroma and flavour. Aust. J. Grape Wine Res. 11: 139–173; 2005 (click here to order).