The results of a DNA test, released by Wine Australia last week, are making trouble for 20 or so Australian wine estates.
Last year, after an inspection of vines, doubts were raised about whether a grape held in the Monash germplasm collection in South Australia really was Petit Manseng, as it was labelled.
DNA tests were done to compare the Monash specimens with references specimens held at INRAE in Montpellier, France. It turned out the grape was actually Gros Manseng.
Both Petit and Gros Manseng originate from the Basque region of South West France. The main differences between the two are the size of the grapes, and the fact that Gros Manseng produces a higher crop yield, but noticeably less elegant wine than Petit Manseng. Vines labelled as Petit Manseng were imported into Australia in 1979 by the CSIRO (Commonwealth Scientific and Research Organisation), and then released to grape growers. Vines were transferred to the Monash collection in 2013.
Dr Ian Dry from CSIRO told ABC News in Australia that the grapes had been obtained in good faith from the French National Institute for Agricultural Research and that DNA testing didn’t exist at the time.
“Unbeknownst to us, we have distributed something we called Petit Manseng over a number of years,” said Dr Dry.
This is not the first time that grape varieties in Australia have been mislabelled. In 2009, the CSIRO tested Albariño vines from the Barossa Valley, and discovered they were actually Savagnin Blanc.
The CSIRO has so far tested 1,500 grape varieties in its collection. “The major varieties are completely safe,” Dr Dry went on.
There are just over 20 wineries in Australia that make Petit Manseng, mostly in the state of Victoria. According to a statement from Wine Australia, only very small parcels of Petit Manseng have been exported in the past five years. From the 2020 vintage, the wines must be labelled as Gros Manseng.
Wine Australia also said that it’s possible that individual wineries have imported true Petit Manseng, and they are preparing to work with all affected wineries to help them identify their varieties.