How a new yeast can bring down ABV by 2%

hen Antoine Gobert started his thesis under the supervision of Hervé Alexandre at the Dijon University Institute of Vine and Wine in 2016, studies into the ability of yeast to produce less alcohol were few and far between.

“One publication listed strains with potential. I took that publication and carried out my own screening using the yeasts available in the laboratory”, says the researcher, now employed by Sofralab, which had funded his thesis. Gobert eliminated all the strains that had the same alcohol yield as Saccharomyces cerevisiae.

“I also looked at how they performed in sequential inoculation. I made sure that they didn't interfere with the end of fermentation and that they produced fault-free wines”. After a year, he chose the non-Saccharomyces Starmerella bacillaris yeast. “At the time, we were getting decreases of between 1 and 1.5% ABV. After a whole host of tests in 3-litre bioreactors, with controlled agitation, oxygenation and nutrition, I managed to achieve 2.5% ABV”. Sofralab will test its new ‘Starbella’ yeast on a large scale during the next winemaking season. The company will offer it to several partner wineries and is fine-tuning its production and drying method in order to officially launch it before the 2023 harvest.