Paul Epee, Bragato Research Institute

 

January 2025 marked the beginning of the first NGV vintage. NGV prioritises safeguarding the premium wine quality for which New Zealand is renowned, while supporting vineyard profitability through innovative, efficient canopy systems that reduce vineyard operational costs. The programme investigates the performance of three novel canopy systems: six vertical cordons with 1.8 m vine spacing (6V), nine vertical cordons with 2.7 m vine spacing (9V), and 12 vertical cordons with 3.6 m vine spacing (12V). These are compared with the control or commercial standard in the vineyard block (pruned vines of 2-, 3-, or 4-cane).

A previous article (Issue 157) illustrated these canopy systems and presented results of their vineyard performances during the 2024-25 growing season. In short, the new canopy systems encouraged early-season canopy development and reduced shoot vigour, resulting in relatively less dense canopies. This means that with the new canopy systems, fewer passes for trimming and leaf plucking might be needed. Sugar accumulation was not compromised in the 6V system, indicating that grapevines can ripen the same quantity of grapes with less leaf area than they currently do on cane-pruned vines.

This article presents key results from the 2025 vintage (with some insights into the current 2026 vintage), from winemaking to the sensory evaluation of wines from the NGV trial sites. To maintain consistency with the previous article and for simplicity, only data from two sites are shown: the Paul’s Road Whitehaven site, referred to as Rapaura, and the Indevin Toi Downs site, referred to as Awatere. Both sites were planted with Sauvignon Blanc. Since the 9V and 12V systems are not yet fully developed, their performance is not presented.

 

Sugar and YAN were lower in the new canopy system in the 2025 vintage, but these results improved in the following year

Juice from control grapes had the highest sugar concentration (Table 1) because control vines had a higher leaf area to fruit mass ratio. In most cases, the difference in sugar concentration between 6V and control was less than 1.5 Brix. For example, at the Rapaura site, the control and 6V were harvested the same day and were only 0.7 Brix apart. The same trend occurred at the Awatere site with 6V, where the ripening period was extended by 12 days to achieve the same sugar level as the control (Table 1). Earlier in the 2025 vintage, it was decided not to adjust the crop level to allow the new canopy systems to express their potential under a high-cropping scenario. Interestingly, in this 2026 vintage, yields were moderate, allowing new canopy systems to reach similar sugar concentrations at almost the same time (Table 1). This means that in high-cropping years, fruit thinning might be required to ensure adequate sugar accumulation with the new canopy systems.

At most sites, titratable acidity (TA) was highest in control juice when control grapes were harvested earlier than the other treatments, including at Awatere (Table 2). Where control and 6V were harvested on the same day, as at Rapaura, TA was similar. At some sites, TA was comparable across treatments regardless of harvest date. Malic acid showed the same pattern: concentrations were generally higher in the control and lower in later-harvested treatments, but similar when treatments were harvested on the same day (Table 2).

YAN was higher in the control juice and lower in 6V, with the decrease most pronounced at the site with the highest yields and least pronounced at lower-yield sites, such as Rapaura (Table 2). At Awatere, however, YAN was slightly higher in 6V (Table 2). Apart from this exception, the new canopy systems generally had lower YAN. In the 2026 vintage, with a relatively lower crop, YAN levels improved markedly in NGV canopy systems compared to 2025, confirming an assumption that the high crop levels diluted grape nitrogen. However, it is also possible that the NGV vines are gradually adapting and adjusting to their new physiological state.

Generally, fermentation was faster for control wines, and no relationship was found between fermentation duration and initial juice sugar concentration. However, lower YAN concentrations may have led to longer fermentations.

 

Wine chemical composition was similar for control and 6V in most sites

Alcohol was generally higher in control wines, following the same trend as juice sugar. Glycerol levels were stable across treatments and trial sites, ranging from 5.0 to 7.0 g/L. Wine pH varied little between treatments. At some sites, such as Rapaura and Awatere, wine TA was highest in the control. Volatile acidity remained at very low concentrations, never exceeding 0.3 g/L.

Most thiolic compounds (3MH and 3MHA) were highest in control wines, except at one site, where all three thiols were highest in 6V. However, 4MMP had statistically similar concentrations in both treatment wines at three sites (including Rapaura). For the Awatere site, 4MMP was highest in the control (Table 3).

Methoxypyrazines were detected in higher concentrations in control wines.  (Table 3). Of the three methoxypyrazines, IBMP was detected at all sites and in all treatment wines, whereas SBMP was detected only in the Awatere wine (Table 3 note). As with YAN, it is hypothesised that the high crop level might have diluted the concentration and development of these aromatic compounds. Interestingly, though, the differences in methoxypyrazine and thiol concentrations did not always stand out in the sensory perception.

 

Sauvignon Blanc wine quality was preserved in the 6V canopy system

At the Rapaura site, all sensory attributes were statistically similar for both wine treatments, except for “stone fruit”, which was rated higher on the control (Figure 1-A). Although the control wine was rated slightly higher for typicity, it did not differ statistically from 6V (Figure 2-A).

The control wine from the Awatere site had more thiolic and greener characters than the 6V wine, whereas the 6V wine scored higher for floral aromas and balance (Figure 1-B). The typicity score of the 6V wine was similar to that of the control (Figure 2-B). In addition to the Rapaura and Awatere wines, 6V and the control wines were rated equally for typicity at two other sites.

Despite minor differences in their individual sensory attributes, both wines (control and 6V) had similar overall sensory profiles. These results show that the 6V canopy system – the only one of the three that had reached full canopy development – maintained Sauvignon Blanc quality.

Key takeaways

The 6V canopy system produced fruit with lower YAN levels and slower fermentation rates, likely due to heavy crop levels in the 2025 vintage; however, in the 2026 vintage, YAN levels were comparable to the control. Although 6V wines showed generally lower methoxypyrazine and thiol levels than the control, other metabolites remained comparable. Importantly, higher methoxypyrazine and thiol concentrations did not always translate into a more intense ‘green/herbaceous’ and ‘tropical/fruity’ aroma perception. The 6V and control wines performed similarly in sensory and typicity evaluations, confirming that this new canopy architecture may offer viticultural benefits without detriment to wine quality.