Published: 15 Nov 2018
Odds are most of us can tell the difference between a pint of Boag’s or Cascade. But can you taste the difference between a cuvée from Coal Valley and one from Pipers River?
Hugh McCullough is using light to find the compounds in Tasmanian sparkling wine that identify exactly where the grapes were grown.
“I’m measuring 2,500 wavelengths for each of 118 sparkling wine juice samples from around the state,” Mr McCullough said.
“Tasmanian sparkling wine regions have diverse climates and soils which impact on the flavour and feel of the wine. We are investigating what chemical compounds might be responsible for these distinctions in flavour.
“Our work will help Tasmanian sparkling winemakers protect their brands and their wine’s special identities – this research is the first step to discovering the regional attributes that make Tasmanian sparkling wines unique.”
Mr McCullough is a Masters Candidate from Plumpton College in East Essex, UK, and is collaborating with the Tasmanian Institute of Agriculture (TIA), where he has access to expertise in wine research and specialised equipment.
He is using a scientific technique called infrared spectroscopy.
“Infrared spectroscopy involves shining a beam of light into the wine juice and picking up the reflections that bounce off the different compounds,” Mr McCullough said.
“Each wine has its own unique ‘spectral fingerprint.’
“By looking very closely at the fingerprint—the different reflections—we can get an idea of the groups of compounds that make up the wine juice,” he said.
These compounds may be responsible for the delicacy of a Pipers River sparkling, or the ‘grippy’ structure of Coal Valley bubbles.
“A Pipers River sparkling wine has a more delicate flavour because the grapes are grown in cool, humid weather,” Mr McCullough said.
“Coal Valley’s ‘grippiness’ comes from a sunny, drier climate. This causes the grapes to develop thicker skins and gives the wine darker fruit flavours.”
Mr McCullough said the regional provenance of Tasmanian wine will become more important as the wine industry and production grow.
“In other wine-growing countries and states, winemakers must specify the region or zone where the wine was produced.
“However, not all of Tasmania's wine growing zones are big enough to be legally defined, so the entire state has so far been considered one region,” he said.
“As Tasmania’s wine industry grows, we need to be aware of the science behind the flavours of our regions.”
Mr McCullough’s trial is breaking new ground for Tasmanian wine with this low-cost tech.
“Infrared spectroscopy is used by other agricultural industries for quality control because it is efficient and instantaneous, but this is the first time that light waves have been used to analyse the flavour of Tasmanian wine.
“This technology may have huge potential for the wine industry.”
Mr McCullough’s research is part of a major sparkling wine research project funded by Wine Australia and led by TIA’s Dr Fiona Kerslake.
More information is available at utas.edu.au/tia/sparklingwine
This article appeared in The Examiner and The Advocate on 15 November 2018.