Pinot Noir Research

NZ produces some excellent Pinot Noir wines and would like to produce more to meet market demand, but the Pinot Noir vine is fickle in yield and expensive to maintain and harvest. In June 2018, Rural Delivery reported that the industry was beginning research projects exploring ways of improving yield without sacrificing the quality of wine. Some findings are beginning to emerge as this research continues that will guide further, even more targeted work.

Pinot Noir (PN) is New Zealand’s leading red wine export with PN vineyards covering around 5700 ha, half of which is in Marlborough with the rest mainly in the Wairarapa, Hawkes Bay and Central Otago.  However, this area is dwarfed by the 25,000 ha of Sauvignon Blanc. Some vintners believe that the industry has become too reliant on white wine exports and see the need to diversify. The excellent reputation of NZ PNs coupled with the increasing demand internationally suggest that increased plantings of PN grapes would be a good investment. 

However, it’s not that simple, as Jim White, technical director for Cloudy Bay Vineyards in Marlborough, explains: “PN is quite demanding in terms of climate and soil, so it is not planted widely around the world, but in NZ we're lucky enough to have a few places where it’s slotted in really well and results in some really nice wines. However, it is a very fickle variety, and we get a lot of variability from season to season, not only in yield but also in style and quality of the resulting wines,” he says.

“It's also a variety that demands lots of inputs in the vineyard, a lot of hand work throughout the growing season. Early in the season there’s shoot thinning to ensure that we've got an even spread of fruit throughout the canopy. We're often removing leaves by hand because the bunches of grapes need a lot of sunlight to develop the colour and tannin in the skin. Closer to harvest we're thinning out the bunches that haven't changed colour to try to get a uniform amount of colour, which will give us uniform ripening. Then we need to harvest by hand. The net result is we get the style and quality that we want but a low yield.”

“These processes don't favour mechanization compared with varieties like Sauvignon blanc, and the problems with availability and cost of labour start to stack up against the economics of PN growing and wine making.”

Traditionally, keeping yields low to ensure high quality has worked, but the fickle nature of PN has meant that in some years the yield has been only half what was planned. The see-sawing of yield and quality has made it impossible to ensure consistent volumes of wine to service markets, frustrating growers and wine makers alike. They needed more tools and “levers to pull” to give better consistency. 

Five years ago, the industry set up a $10.3 million research programme funded by the Ministry of Business, Innovation & Employment’s Endeavour Fund and New Zealand Winegrowers, the national industry body for growers and wineries.  The programme has involved the researchers at the Bragato Research Institute, Plant & Food Research, the University of Auckland, and Lincoln University. The aim was to improve yield and consistency without detriment to quality. It involved examining consumer and expert wine taster perceptions of what constitutes high quality PN wines, the chemistry of these wines, and identifying the linkages between viticultural and winemaking factors, chemistry data and consumer perceptions.

Damian Martin, science group leader for viticulture and oenology at Plant & Food Research, says that yield per hectare of grapes was the “lever” the programme focused on initially. “We wanted to understand the yield/quality paradigm, which exists in practice but also exists as philosophy for many winegrowers. Could that paradigm be disrupted or broken? Was it absolute and there was no way to get high quality and high yield at the same time, or could in some situations both good commercial yields and quality be obtained?”

“So, we went looking for vineyards and vines within vineyards that appeared to disrupt that yield/quality interaction, and we found some - after studying about 240 individual vines each year for four years. We found that it is not the same vines that perform well each year, so there is interaction with the season and with the management of that vine each year.

“If all the stars are aligned, we get that sweet spot between yield and quality, but it doesn't happen very often, and we still have quite a few questions around that. We can identify high performing vines only retrospectively – we can't identify earlier in the year that the vine is going to have a good yield or quality potential. So, we are starting to run some experiments to see which management levers we can pull to try to push the vines towards more consistently high yield and quality targets.” 

In working to increase the proportion of high performing vines within a block or a vineyard the researchers have looked at nitrogen and carbohydrate reserves in plants and how they affect shoot and inflorescence numbers. It also seems that a precise level of nitrogen nutrition is important for optimal colour development. 

David Armour, research programme manager at the Bragato Research Institute, has been looking at quality from a consumer's point of view, and also doing some chemical profiling of PN wines. 

“Having trained professionals to do the tasting gives us much clearer clues to follow through the chemical profiling to identify what constitutes a good wine, which the average consumer can't do. We have found that colour is important but for different reasons to different tasters, depending on whether they are an expert or a consumer.”

“With chemical analysis we may getting close to understanding what separates a premium wine from a commercial wine, and this is giving us clues for the future. We can match up individual vines with desirable colour and phenolic potential, but we can't directly measure any of the key aroma compounds in grapes until they are fermented.”

The team has developed tools to accurately identify vines that have met a high-quality specification and yield for that year.  They can then start working back through the season and the management of the vine to understand how that high quality was achieved.  

 A lot of work has been done to develop New Zealand's analytical capabilities so that wine quality can be defined chemically and the transition from juice to wine can be monitored. 

So, can PN wines be produced with greater yields without a reduction in quality? 

The answer is a definite maybe.  Damian Martin says that the high reputation of New Zealand Pinot Noir is has been established by the icon producers who have an almost sacred belief that high quality and low yields are synonymous.

“But one of the things that we have shown is that, although those purists are right, we were also right in our hypothesis – it's all about the proportions.  In vineyards that are managed very carefully and manicured at an icon level where people have targeted low yields, there is a high proportion of the vines that meets the quality specification. Conversely, when the vines are more commercially managed to achieve a higher yield with more mechanisation, there are far fewer vines that meet the quality specifications, but those few vines still exist.”

“So, both parties are right. The icons approach is a risk management strategy, but there is also the possibility to get more of those high performing vines in a vineyard at a commercial production metrics. “