New yeast strain drops alcohol levels by over 1% ABV
Warmer climates and better vineyard techniques have meant it has never been easier to ripen grapes, but with higher sugar levels come higher alcohol levels. To combat this, researchers at the Australian Wine Research Institute have developed a strain of yeast that can produce lower-alcohol wines. During trials, an Aussie Shiraz was made with alcohol levels 1.4 percent lower than a conventionally produced wine from the same grape must. In a test with Chardonnay, the alcohol was 0.9 percent less.
There are several genetically modified yeast strains that can produce lower alcohol wines so a strain has been identified that comes from nature - Metschnikowia pulcherrima or AWRI 1149.
The results, though noteworthy, are not without some issues. The team observed that the Chardonnay samples showed higher levels of ethyl acetate, which can lead to nail polish aromas in finished wines. And while AWRI 1149 is adept at consuming sugars, it dies before the full fermentation process is complete, so a secondary yeast was employed to ferment the wine dry.