Unwanted malo leads to an Australian first

13 Oct 2017
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The release of the first uniquely Australian bacteria isolate for winemaking is proof that big gains can flow from small disappointments. And it’s a great story of sector collaboration and research extension.

A Yarra Valley winemaker was surprised and more than a little frustrated when his Chardonnay went through unplanned and unwanted malolactic fermentation, despite the fact that it was stored at a cool 12° Celsius.

Eveline Bartowsky
Eveline Bartowsky

Once the situation had been sorted out, he rang Dr Eveline Bartowsky at the Australian Wine Research Institute (AWRI) to ask if she was interested to know what had happened. She was.

‘My main role at time was leading the AWRI’s bacteria research program but I also managed the culture collection’, she said. ‘When I was out on road shows talking to winemakers I always said that if they had an interesting wine I’d be keen to look at the yeast and bacteria behind it.’

With colleagues, Dr Bartowsky isolated the bacteria strain, screened it, then characterised it further in both red and white wines. They discovered that it was very robust: tolerant not just to temperature but also to alcohol and pH.

When the AWRI subsequently asked Lallemand if it was interested in exploring the potential of one of a number of new Australian bacteria strains, the Yarra Valley ‘discovery’ was the one it chose.

Lallemand did further screening, then this year ran a trial in Shiraz so it could compare the new isolate with others in its portfolio.

‘There was great interest because there are no Australian isolates on the market despite there being such a focus on Australian terroir and creating a sense of place’, said Dr Bartowsky, who is now working at Lallemand. ‘We wanted to see if we could provide an Australian input at the bacteria or yeast level and have an impact.’

They could. Both Dr Bartowsky and Lallemand Australia’s Commercial Director Oenology & Brewing, Jason Amos, were surprised and impressed by how distinctive the wines were.

‘They were very different to those made with bacteria from our current range and that was important’, Mr Amos said.

‘It was clear that it was a robust and versatile isolate, and it’s great having an Australian isolate to add to the Australian wine story, but we had to be clear where it would fit in the mix.’

- Jason Amos, Lallemand Australia’s Commercial Director Oenology & Brewing.

Everyone involved is now convinced, and the new isolate will be available for the 2018 vintage. It has been produced, technical data sheets are being written, and the AWRI has sample wines to take out on its road shows.

Mr Amos believes an expanding range of bacteria gives winemakers a new tool to help ‘craft their style’.

‘All wineries have to decide whether or not to do malolactic fermentation, and if the answer is yes then they decide whether to use cultured bacteria or to simply let indigenous microflora dominate the fermentation. And many don’t go beyond that.’

‘However, some wineries now see that how they run malo can have an impact on the style of wines they want to produce and their ability to make diverse wines for different markets.’

‘The end story for me is the celebration of good microbiology.’