The Evolution of New Zealand’s Sauvignon Styles

(This is an updated adaptation of previously published articles in World of Fine Wine, Slow Food, Essencia do Vinhos, Mondial Sauvignon Blanc and others. Jan. 2020

Ever a sucker for ‘shock of the new,’ I was lucky enough to stumble on to Marlborough sauvignon blanc accidentally during a blind tasting while captaining the Oxford University Blind Wine Tasting Team around 1987-88. Completely unaware that New Zealand even made wine, let alone was capable of dressing sauvignon blanc in such a wild array of psychedelic varietal characters, I was totally stumped. Eventually guessing a cool climate Sauvignon de St-Bris from Chablis, I wondered out loud whether it may have been made by someone keen on magic mushrooms.

That Marlborough sauvignon, like many after, had effortlessly Pacific Rimified Sancerre’s classic ‘cat’s pee on a gooseberry bush,’ into an outlandish fruit salad tossed full of tomato leaves, nettles, capsicums, and pepper, dressed with essence of passionfruit, gooseberry and grapefruit. Laced with an edgy, refreshingly relentless acidity and – dare I say – deliciously quimmish undercurrent, here was sauvignon let off its leash: sexy, sassy, full of irony and wit...

Most New Zealanders freely admit the overnight success of sauvignon had more to do with serendipity than industrial intent. It took the hearts and minds of those who weathered under cold, grey British skies to point out that Marlborough sauvignon was both special and pregnant with possibility. Not only was the UK market served on a silver platter, but as Australian viticulturist Dr Richard Smart has previously noted, it lucked in with ‘the right variety, the right clone, in the right place, at the right time.’

Banking off the Upper Loire sauvignon's rained out 1987 vintage and uncharacteristically over-ripe, overblown 1989, New Zealand turned a trickle of sauvignon into a varietally supercharged torrent that captured a huge chunk of the UK market. After Montana’s 1989 (rebranded now as Pernod Ricard’s Brancott Estate) won the Marquis De Goulaine Trophy for best Sauvignon Blanc at London’s 1990 International Wine & Spirit Competition, sales rocketed to over a million litres. Producing in excess of 200,000,000 litres of sauvignon today (86% of total production), New Zealand hasn’t looked back since.

Much of Marlborough’s and, by extension, New Zealand’s success has been driven by a commercial ‘formula’ that continues to lay endless golden eggs. Take a sauvignon blanc vine, graft it onto SO4 root stock, plant it in a spacious 2000 vines per hectare (versus Sancerre’s more typical 8,000). Train the vine to carry fruit on four to six canes (versus Sancerre’s one or two) and position shoots vertically on an high trellis so it can comfortably carry up to 6 - 10 tonnes per acre (versus Sancerre’s 2-4). Machine harvest, bung it in stainless steel tanks, ferment with 6gms residual sugar, bottle, and, as Kiwis say, ‘Bob’s your uncle.’

Driven by a Southern sun that cranks out 30% more UV than up north, with cool nights and a steady maritime breeze locking in high natural acidity, this classic recipe consistently delivers a magical mixture of herbs and tropical fruit. So far, no other wine producing country captures these characters as well or as consistently.

Although sauvignon has played a central role in the Upper Loire and Bordeaux for centuries, now, as the first New World region to completely embrace sauvignon, New Zealand has proved itself uniquely positioned to cast it afresh.

As to why sauvignon blanc is so well suited to Marlborough, Pernod Ricard New Zealand viticulturalist Mike Insley responded: “Climate has to be the main influence. Warm and dry enough to fully ripen commercial yields, but cool enough to retain acidity and flavour precursors (methoxypyrazines, thiols etc) usually ‘blown off’ in warmer climates. Our longer grape development phase compared to warmer climates may play a part too, where the French often talk about 100 days between flowering and harvest, Marlborough may push 120 - 130.”

Insley continued, “Our winemaking - long, cool fermentations to retain varietal intensity, the extensive use of stainless steel and refrigeration expertise borrowed from the dairy industry, has suited the development of markets looking for fresh, fruit forward wines. Marlborough style relies on purity and strength of varietal character for their drinkability and commercial success. There is relatively little "winemaker artifact" involved - little or no oak or malo lactic fermentation. The flavours in archetypal Marlborough Sauvignon are mostly created in the vineyard, then released during the winemaking process.”

New Zealand also got lucky with its original Sancerre clone, UCD 1, which accounts for 90% of plantings. Although newer clones (316, 317) brought in from Bordeaux in the 1990's provided good palate weight, they never matched its moderate productivity and varietal intensity. Slotted into ‘The Formula,’ UCD 1’s solo voice helped forge a perfect lens for viewing distinct, sub-regional, terroir derived styles. Three have emerged so far in Marlborough.

Rapaura’s ‘cobblestones piled under vines’ terroir defines the Wairau Valley’s northern side. Slightly higher temperatures there yield earlier ripening and lowered acidity. A mixture of young, relatively infertile alluvial soils and sieve-like, free draining river gravels produce dense, vigorous vines growing in silty pockets, next to struggling, stressed vines growing in gravel lenses, often within the same vineyard row. This plays out through marked differences in fruit exposure, yields and ripeness levels at harvest, creating a "vineyard blend" within each block.

Rapaura wines tend to be highly aromatic and less weighty on the palate than other regions. Perceptibly softer and riper because of the lower acidity, they are characterised by pronounced sweaty, passionfruit notes that reflect a greater variability of fruit at harvest.

On the Wairau Valley’s southern side, Southern Valleys rest on older, more even soils, mixing loess (wind blown silt) and clay over glacial deposits. More elevated, therefore cooler, the region gets 50% less rainfall than Rapaura, offset by soils that retain water better. The combination extends sauvignon’s growing season by a week or two, resulting in richer, crisper and more pungent characters, with a slight oiliness providing greater mid-palate weight.

The Awatere Valley, just south of Wairau, favours loess and clay with no gravel. Cooler, drier and windier than Wairau, vines there grow smaller leaves and thicker skinned, smaller berries, all of which reduce yield. The combination makes for extremely pungent, nettly, tomato plant leaf characters, denser palate weight and high acidity.

Extending the ‘formula’ to other regions, further south in Waipara and Central Otago’s cooler climates sauvignon stretches into finer grained, more tightly knit, linear styles. Overt fruitiness is often swapped for increased minerality and increased herbaceousness.

Slightly north of Marlborough, Nelson is a touch wetter, Martinborough a touch drier. Stylistically, both are closely allied to Marlborough. Depending on whether sauvignon grows on clays or gravels, Nelson’s styles tip toward Raupara or Awatere. Martinborough’s loess and gravel grown sauvignons are fuller fruited, weightier and softer.

Sauvignon styles shift dramatically further north in Hawkes Bay, crossing a vinous ‘Mason-Dixon line’ above Martinborough as pinot noir yields to red Bordeaux varieties. Increased heat there drives intense herbacousness into subtler cut grass, fresh green bean, sweet pea aromas married to fruitiness more reminiscent of mango, guava, stonefruit and apples. Textures are fatter and acids lower, with styles looking more toward Graves than Sancerre.

In hindsight, sauvignon has steadily colonised the country over the last forty years, all the while, gravitating toward styles that illustrate the soil and climates where it is grown.

New Zealanders have periodically paused to reflect on where to take sauvignon next. A little over a decade ago, the New Zealand government was started by revelations that the French, Australians and South Africans were driving fundamental research into what makes sauvignon tick. Setting aside research grants worth millions of dollars to study sauvignon over the nex decade. Initial studies focused on improvement of aromatics through better yeast selection and growing conditions. Intent on maintaining NZ’s competitive edge, other research aimed to identify aromas consumers enjoy and their underlying chemical compounds. Finally, something has been put back into the old cash cow.

What’s followed has been complicated and controversial. While many agreed that success had come almost too easy, everyone was also aware that if Marlborough’s successful formula ‘ain’t broke, don’t fix it.’ However, where the UK had/have loved Kiwi Savvy style, Americans traditionally had a hard time getting their heads around any ‘salad in a glass’ approach to sauvignon. The vast, untapped potential of the American market risked this ‘modern classic’ sugar coated being blanded away chasing the Yankee dollar.

With plenty of issues worth hashing through at mid-life, the New Zealand Society for Viticulture and Oenology hosted the country’s first sauvignon blanc seminar in November, 2004. Professor Denis Dubourdieu was invited to headline discussion in recognition of his recent groundbreaking research into sauvignon at Bordeaux University.

It was becoming increasingly clear that sauvignon is much more complex than previously thought. Leading with impressive aromatics in the glass, punchy up-front fruit, followed by a mid-palate dip and back palate rebound, sauvignon blanc (and its red cabernet cousins) are often tipped as having a large hole in the middle. Dubourdieu explained then that sauvignon grapes differ from others in that flavor disappears relatively quickly in the mouth, but comes whoosing back within seconds after swallowing though ‘retrofaction,’ as a wave of aromas re-enter the nose through the back of throat.

Dubourdieu’s break through research identified new groups of thiols (sulphide compounds), that along with methoxypyrazines (MOP), drive sauvignon’s behaviour. Thiols are inactive aromatic and flavour precursors unlocked by yeast fermentation, which explains why sauvignon grapes are not as aromatic or flavourful as the resultant wine. MOPs are responsible for the myriad of herbaceous characters found in sauvignon: capsicum, cut grass, nettles, tomato plant leaves, green bean, asparagus, etc.

Thiols have a double-edged nature, capable of adding positive or negative characters to wine. Dubourdieu’s research put chemical forumulas to the thiols that produce positive aromatic and fruit characters: 4MMP relates to cats pee, broom and boxwood characters; 3MHA cat’s pee, sweatiness, passion fruit; 3MH grapefruit, passion fruit; 4MMPOH citrus zest; 3MMB cooked leeks; and 2FM, roasted coffee. Other, potentially more negative thiols--commonly called mercaptans--produce rotten egg, onion and burned rubber aromas in wine. Each thiol type is now known to concentrate either in grape skin or pulp; so changes in viticulture and winemaking could manipulate their balance in the final wine.

Other Dubourdieu findings indicated that methoxypyrazines remain stable over time, whereas more volatile thiol derived fruitiness diminishes.This explains why aged sauvignon can sometimes end up tasting like alcoholic, canned asparagus soup. As fruit drops away, becoming more savoury, the asparagus-like methoxypyrazines become more dominant. So, altering the balance between the two could improve sauvignon’s longevity.

It also turns out that young vines provide more intensely flavoured fruit than older vines. This may have contributed to NZ’s punchier, fruit forward styles compared to older vineyards elsewhere in the world. As New Zealand’s average vine population crosses the 30-40 year threshold, flavours may naturally shift toward the savoury, mineral characters associated with Upper Loire styles.

One of the more problematic aspects of Dubourdieu’s research established sauvignon’s vulnerability to copper fining, which can indiscriminately strip, both ‘good’ and ‘bad’ thiols of their aroma making capacity. Over the course of the last decade copper fining has been one of the main strategies used to avoid negative sulphide reduction (mercaptans) under near-anaerobic screw cap seals with their proven tendency towards reduction.

All of this has provided plenty of food for thought over time.

New Zealand viticulturist and former Dubourdieu student, Dr. Damian Martin, has previously suggested ‘the future focus of Marlborough sauvignon should work toward amplifying the difference of site, whereas previously climate had been the dominating factor.’ Others have seen sauvignon searching out soils and climates that deliver later ripening, lowered alcohol and lessened greenish characters, while delivering richer veins of ‘flavour farmed’ thiol driven, passionfruit and sweat characters. Another challenge has been to increase the shelf life and ageing potential of Marlborough sauvignon, while reducing the overtly green characters coming through with age.

Although Professor Dubourdieu hadn't specifically studied the difference between French and New Zealand sauvignons, he thought the latter were delivering a good mix between pyrazines and fruit. Alluding to an old French proverb, he believed New Zealand “must continue to do what people are criticising, because its you.” Recognizing the stylistic model as viable, he suggested any goal should be “continuing to improve quality while maintaining a balance between the greeny pyrazines and taste of tropical flavours.”

Many producers have been steadily doing this since the early 1990s. Palliser Estate’s Alan Johnson, “had drunk his fair share of early Montana styles, finding them very herbaceous, albeit powerful wines.” Recognising how highly consumers valued this style, Johnson nevertheless “felt sauvignon needed more richness and depth of flavour at mid-palate.” Along with many other producers, filling in the hole in the middle while creating more vinosity on the finish became a mission.

Experimenting with irrigation to create moderate water stress, shoot thinning and reduced bunches per canopy has intensified flavours and created richer mid-palate texture. Dialing leaf plucking first up, then back down to around 50% exposure of bunches has created a more complex mix of ripe and unripe characters. The fact that consumers haven’t noticed these evolutionary changes is very telling of how well they’ve fixed ‘The Formula’ without breaking it.

Over time, other producers have consciously toned down herbaceousness and overt fruitiness, intent on capturing some of the minerality and finesse associated with French Sancerre. Still others have ‘funked up the fruit,’ playing with lees contact and different yeasts to build in positive savoury, marmite-like sulphidic characters.

Tipping in the direction of Bordeaux, other producers employ barrel fermentation, lees stirring and extended ageing on lees to polish textures and knock both the herbal and fruitier edge off aromatics; a technique Selaks’ Darryle Woolley called (fruit) “bomb proofing.” The result is a more savoury, neutrally fruited, chardonnay-like style. Generally, warmer toned fruit from Hawkes Bay has consistently proved more sympathetic to this approach, but producers from cooler climates have demonstrated it works well in their regions as well. The most adventurous producers take this a step further with native yeast ferments. Highly complex and multi-layered, the more successful examples of this style improve, indeed only come to full fruition, with extended bottle age.

Reflecting on all this, winemaker David Pearce quoted Winston Churchill: “It may not be the end, or even the beginning of the end, but perhaps it may be the end of the beginning. “ Continuing, “As a sauvignon blanc producing industry we are coming to the end of the beginning.

Good job too. The next decades will probably be more exciting than the last and I see better viticulture and winemaking making even better wines. I’m looking forward to it.”