As a child growing up in the bustling metropolis of inner Beijing, Dr Sijing Li was very much the city girl – more interested in words than scientific phenomena.
‘I lived in a city of 21 million people. I had no experience or interest in the natural world’, she concedes.
‘My only passion was reading and collecting books. My high school had a large library and I spent almost every lunch break there, re-shelving books and helping people with their selections’, Dr Li recalls.
‘I think this experience is why I am so fond of cataloguing systems. I know exactly where to look for a particular field of knowledge. It has proven a very useful skill in my research career!’
Dr Li said because she loved reading so much, she naturally gravitated towards humanity subjects at school. When it came time to choose a university course, there was no hesitation – she enrolled in a Bachelor of Chinese History.
But after a year of studying, Dr Li discovered that although she loved history and literature, she didn’t want them to be her career.
‘I wanted something more practical, where I could quantify the value of what I created through my work.’
However, in China, there is no option to ‘swap over’ from humanities to science at university level. ‘My only option for going into a different field was to go abroad.’
Dr Li applied for a number of courses and was accepted into three programs: International and European Law at a university in The Netherlands; Economics at a Singaporean university; and Viticulture and Oenology at the University of Adelaide.
‘I chose the latter because I liked the romanticism of working in a sprawling and luscious vineyard and making delicious wines. It also sounded practical – there was a clear career path at the end of this degree. I didn’t think of it as going into science at the time, because I didn’t think winemaking was science. I thought of it more as a trade.’
Dr Li was enamoured of science from the get-go and took every opportunity on offer, including a summer school scholarship on a smoke taint project.
For her Honours project, Dr Li and her supervisors studied the process of generating alternative oak products from decommissioned oak barrels. Their project proved that there was a pool of precursors present in the previously unused wood, and upon re-toasting could generate new oak volatile compounds that could be suitable for use in winemaking. Her PhD was a part of a larger project that looked at reducing alcohol levels in Australian wines.
‘After my PhD I was fortunate enough to get a job at the National Wine and Grape Industry Centre at Charles Sturt University looking at the regional typicality of commercial Australian Shiraz wines. This time, my main focus was not on the macromolecules but on the volatile compounds in wine.’ The NWGIC is an alliance between Charles Sturt University, the NSW Department of Primary Industries and the NSW Wine Industry Association.
Dr Li said she finds working in wine science ‘endlessly fascinating’.
‘Wine is very complex from a chemistry point of view. There is so much work that goes into making a bottle of wine, and every step of the way contributes to the chemical composition of the wine. I love trying to understand these processes and trying to improve them.
‘At the same time, wine science is also sensorial. There is immense pleasure in evaluating the sensory aspects of a wine, from its colour, aroma, to its flavour, mouthfeel and aftertaste. The nature of wine makes its science both rigorous and intimate at the same time.’
Dr Li’s next project is on Smoke Taint, a partnership between the Australian Wine Research Institute (AWRI) and NWGIC and supported by Wine Australia. The project is focused on expanding the grape and wine sector’s ability to analyse smoke taint samples.
Some grape phenol glycosides and volatile phenols are reliable markers for smoke taint. Their concentrations in grapes and wine can provide winemakers and grape growers with the tools to help harvest and winemaking decisions. At the moment, only a few labs have the analytical capacity to measure these compounds.
‘The AWRI have generously agreed to help share their methodology – a great example of the collegiality within the Australian wine sector. Transferring these methods to NWGIC can afford the wine sector more analytical capacity in preparation of emergency response in the event of large-scale bushfires in the future years’, Dr Li said.
This means that the winemaker and grapegrowers may be able to get the analytical results faster. Another arm of the smoke taint project involves correlating the levels of targeted compounds in smoke exposed grapes to wine sensory outcomes. Shiraz, Chardonnay and Pinot Noir grapes containing phenol glycosides indicative of smoke exposure at very low, low, low-moderate and moderate levels have been harvested. The wines made from these grapes will go through sensory evaluations to establish links between the levels of smoke taint markers in the grapes and the perceivable sensory taint in wine.
Dr Li said this knowledge can assist harvest decisions at low to moderate levels of smoke exposure for the grape cultivars studied.