New Zealand’s most planted red variety is also one of its most site-sensitive, so the question for growers and winemakers has never been as simple as “Pinot Noir, yes or no?” but “which clone, on which site, for which style?”

To better understand the planting material available within New Zealand, Riversun Nursery, in conjunction with Otago Polytechnic, developed a Pinot Noir clonal trial vineyard. This site has subsequently been used by Bragato Research Institute (BRI) to conduct thorough, objective analyses of wine made from the planting material.

The trial is based at Otago Polytechnic’s Bannockburn Road site, which was planted in 2017 and comprises twelve commercially available clones grafted to 3309 on well-drained, schist-derived soils with moderate water‑holding capacity.

The aim of the trial was to help winemakers and grape growers make informed decisions when planting or replanting vineyards by combining phenological, wine analysis and sensory analysis on Central Otago Pinot Noir in 2024 and 2025.

The findings show vintage drives most of the wine-to-wine variation, yet meaningful and repeatable clonal signals emerge in ripeness, colour intensity and phenolic makeup—insights that translate directly to clonal selection and crop load decisions in cool climate New Zealand.

Methodology

Twelve clones B113, 114, 115, 667, 777, 828, 943, UCD 5, UCD 6, AM 10/5, Abel and MV6 (Figure 1) were planted in a randomised layout, 24 vines per clone, on 3309 rootstock at 2.4 × 1.33 m spacing, with consistent canopy management across the block. Harvest occurred on a single date each season to enable direct comparison of clonal maturity under identical seasonal conditions; baseline yield metrics were captured in 2022–2023, with standardised small lot winemaking in vintage 2024 and 2025. Juice analysis covered juice metrics (°Brix, pH, TA, malic, YAN), finished wine metabolites (alcohol, acids, glycerol), spectrophotometric colour plus CIELab, and GCMS quantification of β-ionone and β-damascenone, followed by controlled trained winemaker sensory panels.

Figure 1. Experimental layout of the Pinot noir clonal trial

From a vineyard standpoint, the trial confirms useful information, differences in crop load, bunch architecture, berry mass and ripening. Abel and AM 10/5 were consistently higher cropping, with larger bunches and lower ripeness at a common harvest date, an obvious flag for rigorous canopy and yield management on cooler sites or for producers chasing a more structural style; by contrast, 943 and 828  tended to have lower crops with smaller berries and bunches, and tended to ripen earlier, offering a shorter pathway to colour and sugar accumulation in marginal seasons. Berry mass clustered around ~1.4 g for most clones over four seasons (Figure 2), but B113, UCD 5 and MV6 skewed slightly heavier, while 828 and 943 were lighter; bunch weight had marked vintage variability in some Dijon clones and MV6. Morphologically, bunch length ranged from ~13 cm (943) to ~19.5 cm (Abel), with 943 showing looser, more open architecture and Abel producing more shoulders. Taken together, these vineyard patterns explain why Abel and AM 10/5 often trailed in °Brix, while 943 and 828, with their smaller berry mass and lower yields, reached higher levels of sugar maturity.

Figure 2. Average single berry mass, per clone

In the winery, despite identical ferment protocols, 943 repeatedly delivered deeper colour intensity and sat among the highest for total phenolics across both vintages, consistent with its smaller berries and greater skin contribution; MV6 was also associated with higher concentration of phenolics. Conversely, higher cropping Abel and AM 10/5 tracked lower in ripeness at harvest and presented with higher malic in juice and, post MLF, correspondingly higher lactic. The norisoprenoids were informative rather than definitive: all wines exceeded sensory thresholds for β-ionone and β-damascenone, but absolute levels varied by season and clone, with UCD 6 trending high in β-damascenone and 943 consistently strong overall. The colour story extended beyond simple intensity: hue values shifted toward more mature tones in 2025, and CIELab visualisations (Table 1) made the comparative depth of 943 and MV6 immediately obvious.

Table 1. RGB visualization of CIELab results

The sensory panels, staffed by experienced Marlborough Pinot Noir winemakers and run under controlled conditions, largely echoed the wine chemistry. In 2024, panellists rated 943, 777 and AM 10/5 higher for dark fruit aroma, while in 2025 the darker spectrum was more strongly associated with 943 and UCD 5. Visually and on palate, 667 and 943 were judged deeper in colour in 2024, with 667 also perceived as less balanced than its peers that vintage; in 2025, 943 and UCD 6 were perceived deeper in colour. When it came to overall complexity, 943 ranked higher than other clones, but only significantly in 2024 when compared to 667, 943 remained a top performer in 2025 even where statistical differences were not present.

Seasonal context, however, was the point of difference, and this is perhaps the study’s most useful take-home for planning and risk management. The first two seasons of measurement (2021/22 and 2022/23) were notably warmer than the latter two (2023/24 and 2024/25), with higher growing degree days and different heat distribution during ripening. This seasonal swing manifested in juice and wine in intuitive and nonintuitive ways: 2022–2023 generally produced higher °Brix at harvest, while 2024–2025 showed higher juice pH and lower TA, a pattern that could partly reflect sampling method differences between the juice tested direct from squeezing in Central Otago (seasons 2022 and 2023)  versus maceration derived juice (seasons 2024 and 2025) due to the well documented influence of cold maceration on acid balance. PCA cleanly separated the 2024 wines toward red fruit/floral/spice with higher glycerol, and the 2025 set toward greater phenolic structure, darker fruit, body and alcohol (Figure 3). In practical terms, clone effects were additive but secondary to the variances in the two vintages of winemaking.

Figure 3. PCA combining all wine and sensory analytes across 2024 and 2025

Taken together, the Riversun/Otago Polytechnic clonal trial offers a practical map for matching Pinot Noir clone to site and style in cool climate New Zealand. If your goal is reliably deeper colour, firmer phenolics and darker fruit, 943 is a standout across seasons, with MV6 close by in phenolic strength; expect higher alcohol in warmer years and consider moderating extraction if tannin build-up outpaces fruit. If you’re farming cooler sites or targeting more generous crops, Abel and AM 10/5 will need early and assertive crop load management to close the ripeness gap, or else plan for later picks. UCD 6 presented higher aromatic weight via β-damascenone and colour stability in 2025.

Above all, the study reinforces that clonal choice is not a magic bullet but a lever; the season plays the most important role, the site frames the possibilities, and the clone helps you tune the outcome. For those contemplating new plantings, the evidence here supports a mixed clone strategy that builds resilience against seasonal variability while giving the cellar options at blend time.

Acknowledgements: Trial vines and rootstocks were donated by Riversun Nurseries; field operations were managed by Otago Polytechnic, with winemaking and analytical work conducted at the Bragato Research Institute. Full methodological details, datasets and references are contained in the final report in the NZW Research Library.