Are varietal clones ready to stand their own ground? Nick Bulleid investigates.
In November, NSW Department of Primary Industries organised a pair of shiraz clonal workshops in Canberra and the Hunter. The organisers, Darren Fahey and Adrian Englefield, invited me to take part to comment on experimental wines and lead discussion on a selection of commercially available monoclonal shiraz.
Darren’s introduction quoted Graham Gregory’s 1966 report for the (then) NSW Department of Agriculture:
The most significant feature of grapevine research throughout Europe is the tremendous emphasis that has and is still being placed on clonal selection.
Little had been done in Australia at that time, but how things have changed!
Mike McCarthy from SARDI then gave an overview of the history and clonal development in shiraz and Mark Rowley of Wine Australia some statistics on global and domestic trends.
Nick Dry, the Yalumba Nursery viticulturist, gave detailed information on shiraz/syrah clones in Australia and France. He also threw light on the origins of the familiar Australian clones – the PT clones from Griffith, the R clones from Tahbilk’s 1860 vines, the Bests material (strictly, a massale selection), Harry Tulloch’s trials, probably of isolates from the Barossa that yielded 1654, 1125, 1127 and 2626, Hans Loder’s Barossa selections, including the popular BVRC12 and BVRC30, and the recent SARDI clones one to 10.
However, it was Yalumba’s own EV and BV selections that intrigued me, these selected from the Eden and Barossa valleys respectively. Yalumba winemakers have rated wines from the EV clones as more perfumed, ‘cool climate’ in style and ‘like shiraz viognier’, while the BV clones were mostly rich, with powerful tannins – this when grown on the same site.
Clones of shiraz have the same DNA, so how can this be? Do clones remember? A crazy thought, but perhaps not. Nick said the differences were probably maintained through RNA. This begs the question: How?
My guess is that switching genes could be involved, turned on or off over the mother vine’s long experience of its environment. I asked Nick whether Yalumba had found any regression. “Not yet,” he replied – it is too soon to know.
Mike McCarthy then returned with a tasting of experimental wines made from four clones grown in Great Western, the Barossa and the Riverland in 2016. These were 1654, BVRC12, BVRC30 and R6WV28. The wines were masked within each region.
Most participants had no difficulty identifying the Great Western wines, but the other two brought some uncertainty. I had a strong preference for R6WV28 and then BVRC12 from Great Western, but thought the former suffered from being over-ripe and jammy at the other two locations. Overall, I thought BVRC12 performed well, with 1654 my least preferred.
Tracy Siebert from the AWRI gave a presentation, ‘Black pepper flavour in shiraz: does the clone have an influence?’ Her research has shown that the aroma detection threshold in red wine is 16ng/l – only about eight times that of TCA – although 20 to 25 percent of her panellists were unable to detect it at all. Region, climate and clone are clearly all important. She found rotundone to be higher in Adelaide Hills, Grampians and Canberra-region wines than five other regions and it was particularly high in 1999, 2000 and 2001 Clonakilla shiraz viognier.
In 2008, 35 SARDI clones at the Nuriootpa Research Station showed concentrations of 6ng/kg of grapes or less while nine clones in the Canberra district had between six and 17ng/kg in 2009. Two BVRC clones and 1127 were the highest.
Across the Barossa Valley, Mount Langi Ghiran and the Riverland, rotundone was highest at Langi, with the Riverland ahead of the Barossa. Levels were higher in 2015 and 2014 than in 2016. Clones R6WV28 and BVRC30 tended to be higher than BVRC12 and 1654. Bramley et al (2104) found distinct variations in rotundone across a single-vineyard block over three seasons.
Her analyses have also detected rotundone in grüner veltliner, a variety known to show white-pepper character, which I confess I’ve never found.
At present it’s not known whether rotundone has a purpose in vine physiology or is residue of another process. Its role in wine quality is yet to be fully investigated, too. Plenty of opportunities for research.
Tim Kirk from Clonakilla and Frank van de Loo from Mount Majura described their experience with clones in the Canberra region. The consensus seemed to be that 1127 performed well, BVRC30 didn’t and that Bests varied between sites.
Results from the final tasting proved elusive, as the characteristics of most wines were confounded by regional or winemaking styles, and worse by heavy-handed oak. The three Clonakilla barrel samples did show clear differences, however. The 1127 had the deepest colour and sweet raspberry and blackberry fruit, SAV19 (Tahbilk) showed the most pepper and black cherry while Bests was more evolved, with red fruit, purity and silky balance.
My overall conclusion was that, while there are consistent differences between the performances of many clones, fine tuning the ideal choice will take many years, as site will be the final arbiter.
Bramley et al. AJGWR 2016.
MORE ON SICILY
Following the fragmentation of my earlier parcel, Australia Post was kind enough to deliver my second delivery of Sicilian wines intact. And how good the wines were! Brief comments follow:
Pietrodolce Etna Bianco 2015 comes from Carricante grapes grown at 800-metres altitude on the northern slope of Mt Etna. It combines intense lemon and grassy flavours with a full, round palate and fresh acidity. Delicious and intriguing.
Pietrodolce Etna Rosso 2015 is grown at 600 metres. Don’t be fooled by the pale garnet red colour. It has a beautiful perfume of strawberry and other berries. After a soft, supple start to the palate, distinctly dry tannins take over, although the fruit lasts well beyond the dryness. No wonder nerello mascalese has been likened to nebbiolo. It would be perfect with pasta or veal.
Hauner Salina Bianco 2015, while grown on an island to the north of Sicily, is also high in origin – about 400 metres. It combines cataratto and inzolia grapes, and shows citrus characters on the nose. The palate is crisp, with a light texture and hints of pineapple appearing.
Morgante Nero d’Avola 2014 comes from around 500m in Agrigento, in western Sicily. I was so impressed by earlier vintages that I used the wine as a varietal example in my lectures at Charles Sturt Uni. It has rich, dark-berry fruit and tannins that, while soft, finish with a distinct south Italian bite. It hides its 14.5 percent alcohol well.
All four wines further demonstrate my comments on Sicilian wines in the Nov/Dec issue and are great examples. They’re imported by Trembath and Taylor.