Published: 27 Feb 2019
Former winemaker and now TIA researcher Dr Rocco Longo is taking the guesswork out of creating beautiful sparkling wines.
Rocco is building an instrument that will attach to a grape press and tell winemakers when it’s time to stop squeezing the juice from the grapes.
It measures the amount of phenolics coming from the seeds and skin of the grape.
“The more you press, the more phenolics you are able to extract” Rocco said.
“Phenolics are good, from one side.
“From the other side, if you produce sparkling wine or white wine you don’t want too much phenolics because they give you that gritty mouthfeel when you drink the wine.”
To stop the pressing at just the right time, winemakers currently have to taste the juice at regular intervals.
And Rocco knows just how hard this can be.
“There are so many factors that can influence the winemaker’s testing,” he said.
“Like if the winemaker is unwell that day how can they actually test the juice in a reliable manner? “Or if it’s too cold or too warm, this also can have an impact on the sensory test.”
Rocco’s device uses spectroscopy to determine the concentration of phenolic compounds in the juice.
This information is then fed back to the winemaker in real time.
Rocco grew up in Italy and studied viticulture and winemaking at the University of Turin before moving to Australia ten years ago.
He worked as an oenologist in Victoria’s Alpine Valley for more than four years and is currently pursuing postdoctoral research in pinot noir provenance and sparkling wine at TIA in Launceston.
Rocco’s device will initially be designed for sparkling wines, and will be trialled in a commercial winery.