Non-conventional wine yeasts: interspecific yeast hybrids
Background
Interspecific hybrids are being generated between commercial wine yeasts and non-Saccharomyces cerevisiae species that have winemaking potential, to produce novel non-genetically modified (GM) wine yeasts which impart unique flavour characteristics. Hybrids generated to date typically share properties of both parents, including the robustness of the wine yeast, with, for example, improved low temperature growth characteristics of the non-S. cerevisiae parent. The composition of the wine made using hybrid yeasts is different to what is achieved when using S. cerevisiae wine yeasts. For example, there are differences in the concentration of aromatic compounds, such as ethyl propanoate (‘fruity’), 2-methyl butyl acetate (‘banana’), hexyl acetate (‘lolly’) and 3-methyl butanoic acid (‘cheesy’).
Progress
A number of wineries participated in trials using some of these non-conventional wine yeast strains during the 2007 vintage. Hybrid strains of Saccharomyces cariocanus/S. cerevisiae (AWRI 1502), Saccharomyces kudriavzevii/S. cerevisiae (AWRI 1503) and Saccharomyces bayanus/S. cerevisiae (AWRI 1505) were included in this trial. Wines were made from Chardonnay, Semillon, Viognier, Merlot and Cabernet Sauvigion grapes. Sensorial and chemical analysis is underway.
A selection of these wines were used in a workshop titled 'Winemaking with non-conventional yeast' at the 13th AWITC held in Adelaide during 2007. Winemakers participating in the workshop considered the hybrid yeast made wines to not only have novel flavour and aroma profiles, but to also have a more complex and rounded palate structure.
AB Mauri Yeast produced AWRI 1502 in active dried yeast form for the first time for the 2007 vintage and in sufficient quantity to carry out evaluations under winery conditions. AWRI 1503 has undergone winery trials in a dried yeast format for the past three vintages and is now being actively promoted by AB Mauri Yeast in Europe and South Africa, with emphasis on fermenting red grape varieties.
In France, the hybrid wine yeast AWRI 1503 received a 'Commendation' in the innovation awards at the 2007 SITEVI Exhibition while in South Africa, a Slaley Estate wine made with AWRI 1503 won a gold medal for the 'Best Cabernet Sauvignon' at the 2007 Stellenbosch Young wine Show. Here in Australia, a viognier wine produced by Oliver's Taranga Vineyards received a glowing review by Huon Hooke in The Sydney Morning Herald (13 November 2007) with a score of 95/100. This 'Top Aussie White' wine was described as 'marvellous and quite complex…with rich spicy, honey and apricot aromas…utterly delicious' . This wine is a blend of wines using the hybrid yeasts AWRI 1502 and AWRI 1503.
From the 2008 Australian vintage, three hybrid yeast will be commercially available from AB Mauri Yeast as Active Dried Yeast products, with AWRI 1502 being promoted as AWRI Fusion, and AWRI 1505 as AWRI Cerebay, while AWRI 1503 retains its original name.
Highlights
- Three different interspecies hybrid yeast generated at the AWRI have become commercially available to winemakers as Active Dried Yeast products; AWRI 1503, AWRI Fusion and AWRI Cerebay.
Project leader: Dr Paul Chambers
Project team members:
Publications:
1020 Bellon, J.; Rose, L.; Currie, B.; Ottawa, J.; Bell, S.; Mclean, H.; Rayment, C. Treacher, C.; Henschke, P. Summary from the Winemaking with non-conventional yeasts workshops, 13th AWITC. Aust. N.Z. Grapegrower Winemaker 528, 72–77; 2008 (click here to order).