How Dr Junqi Zhu of Plant & Food Research, Marlborough is helping to predict Sauvignon Blanc yields.
Sauvignon Blanc is a voyage of discovery for New Zealand winemakers who are adding complex new strings to their fruity white winemaking bows with increased barrel fermentation, maturation and lees contact. Not to mention new wave wines fermented in large old cuves, wines matured in ceramic eggs and even the odd wine bottled without sulphur dioxide.
The International Sauvignon Blanc Celebration in Marlborough this year highlighted the diversity of the variety at the Wild Bunch tastings. This story is about these and other innovations in New Zealand today, which prove it is anything but business as usual for the country's most planted grape variety.
"You can't escape that a certain straightforward fruity style will continue but nothing stands still," says James Healy; winemaker, co-owner and founder of Marlborough's Dog Point Vineyards.
He should know, having pioneered the wine that is one of this country's most distinctive Sauvignon Blanc; Dog Point Vineyards Section 94.
The evolution in Sauvignon Blanc styles is taking place nationwide with wines such as Pegasus Bay Sauvignon Semillon and Te Mata Cape Crest Sauvignon Blanc, but nowhere more so than in Marlborough.
Like other stalwarts of Sauvignon Blanc, Healy predicts that Marlborough's regional differences will grow in importance.
"Clear distinctions may already be drawn between Sauvignons from Marlborough's Wairau Valley, Southern Valleys and Awatere Valley. These areas are home to quite different wines, although this is probably not so discernible to the average drinker because most grapes from each area are blended together. This irons out the differences, but I think there's plenty of sub-regional character that people will experiment with."
Hawke's Bay, the Wairarapa, Nelson, North Canterbury and Central Otago also offer distinctive stylistic variations on the Sauvignon Blanc theme, particularly south, where the cool climate accentuates the grape's pronounced acidity and can, depending on the region, lengthen the growing season to potentially exploit wider aromatic flavours.
So, what flavours are emerging in new wave Sauvignon Blancs today?
Savoury, lees influenced ones have led the way so far. Healy says that he and Dog Point co-founder, Ivan Sutherland, hand pick all the grapes for their Section 94 and avoid skin contact because it can create astringent wines with high levels of volatile thiol precursors.
Dog Point Section 94 is made from grapes grown on a big seam of deep silty clay soil that runs up the western side of Brancott Estate and passes into Pernod Ricard land as well.
"We chose the grapes from the Section 94 vineyard (the historic name on the original Lands and Survey maps) because it's a very good site and we knew the techniques we wanted to use; essentially taking unsettled juice and fermenting in barrel. A little like the old fashioned Bordelais style; a hot ferment and new oak," Healy says.
"You'd probably think with our experience of Marlborough Sauvignon Blanc and new oak that we'd have known better than to introduce 100% of it to our top wine; that we'd let a relatively uncluttered version of the fruit come through. That's why we didn't want to use new oak as part of the make up of the wine. The idea with Section 94 is to press the juice to barrel and ferment it with a long time there on lees, without any SO2; to have the wine really evolve in the wood."
The SO2 is added when the wine comes out of barrel and is bottled. Healy also adds that, much as natural wines are interesting, he and Sutherland are not attempting to go down that path – and never have been.
"Our ideas for Section 94 are our own but the use of barrel and the juice preparation was very French; very Bordeaux."
The winning factors for another ripple in the new wave of Sauvignon Blanc is the new 2011 Marisco Pride & Glory; 100% Sauvignon Blanc, launched last year by Marlborough winemaker Brent Marris.
The wine is part of his new Craft Series, a range of small volume, high quality wines. Its release is indicative of the evolution in New Zealand wine.
"We have gone through our child and adolescent years and now we are starting to mature into adults; pushing the boundaries to make a great wine, irrespective of the grape variety it's made from," says Marris.
Pride & Glory is made from hand picked fruit from the Waihopai Valley, which has a higher diurnal variation than the Wairau Valley, and therefore can have more pronounced aromatics, provided crop levels are kept in check. Oak type and shape also offer a new slant on Sauvignon Blanc for Marris, who fermented the Pride & Glory in 1000 litre ovals to accentuate lees influence. The limited temperature control that barrels provided means that the fruit asserts itself less intensely, although there is no question that Sauvignon Blanc's character stands out in this new wine.
"These little aspects make a fine wine; it's about making a wonderful wine, which can age rather than making Sauvignon Blanc with noticeable oak," says Marris.
He suggests styles such as this one can open up a wider market for New Zealand Sauvignon Blanc globally, provided they are widely marketed to tap into a receptive audience, paving the way for other diverse styles.
"There is a great scope of oppportunity to develop new styles of Sauvignon Blanc, which can offer a big plus for Marlborough. I think we will gain a following of people who start hunting out these styles globally from New Zealand."
The middle of the market can be equally exciting for future Sauvignon Blanc because canopy management, vineyard site selection and different regional expresions are all better understood today than in the past.
This includes wines such as Amisfield Fume Blanc, Auntsfield South Oaks Barrel Fermented Sauvignon Blanc, Babich Winemaker's Reserve Sauvignon Blanc, Churton Best End Sauvignon Blanc and Greywacke Wild Sauvignon, among others.
Marris suggests that future success rests on balanced crop levels, lower alcohol, more use of lees contact and less of residual sugar.
"I think if we go down that path with using lees contact and a touch of oak – not necessarily barrel fermentation - and also work with temperature and new yeast strains, then we can keep the fruit as natural as possible and enhance the styles of Sauvignon Blanc in the mainstream market."
Wines such as Pernod Ricard's Chosen Rows are in the top tier of new wave Sauvignons but this large wine company is breaking new ground with mid priced wines too, such as 2015 Brancott B Sauvignon Blanc, 5-10% of which was fermented in oak. Impressive as these wines are, the two that have perhaps the strongest potential to make an impact in New Zealand are the new 2015 Stoneleigh Wild Valley Sauvignon Blanc and the 2015 Brancott Terroir Series Fume; both influenced by oak, which enhances body, richness and complexity of flavour.
All of the wines in this story are the tip of a long list of high quality wines whose makers have steped outside the fruity framework to play a new sound of Sauvignon, dialling up the complexity and turning down the volume on passionfruit and gooseberry aromas.