Clos Ostler

Clos Ostler is a monopole vineyard and wine producer near Duntroon in the Waitaki Valley of New Zealand's South Island. Planted on a north-facing limestone escarpment, it was among the earliest commercial vineyards established in the Waitaki and has become closely associated with the development of the valley as a distinct cool-climate wine region.

The site is distinguished by shallow calcareous parent material and calcium-dominant Rendzic Melanic soils, part of a soil order covering about 1 per cent of New Zealand. Pinot Noir is the principal variety, with smaller plantings of Chardonnay and Pinot Gris.

Established by Jim Jerram and Jeff Sinnott, the vineyard was first planted with Pinot Noir in 2002. It was acquired in 2021 by ACG Wines Ltd, owned by the Roulet Magides family. Its critical record extends across both periods of ownership: Caroline's Pinot Noir received International Wine Challenge gold medals for six consecutive vintages beginning with 2010 and won three national and regional trophies in 2025, while the inaugural EOS Pinot Noir 2022 became the first Waitaki Valley wine to receive a Platinum medal at the Decanter World Wine Awards in 2026.

History

Jerram and Sinnott began assessing the viticultural potential of the lower Waitaki Valley in 1998, when commercial viticulture in the region was still largely undeveloped. Their evaluation included climate observations from three weather stations before the property near Duntroon was purchased in 2001. The vineyard takes its name from William Ostler, an ancestor of Jerram who settled in the district during the nineteenth century.

The first Pinot Noir vines were planted in 2002, followed by Pinot Gris and Chardonnay. Frost and the valley's low heat accumulation made the early development of the vineyard demanding, and frost protection was required during the growing season. The first two decades of Clos Ostler coincided with the Waitaki's transition from a largely untested viticultural area to a registered geographical indication. Caroline's Pinot Noir subsequently attracted repeated international review and received International Wine Challenge gold medals for six consecutive vintages beginning with 2010.

In July 2021, Jim and Anne Jerram sold the vineyard and associated wine business to ACG Wines Ltd, owned by the Roulet Magides family. The family has winegrowing roots in Neuchâtel, Switzerland, and is also involved in the ownership of Yarra Yering in Australia. Winemaking later passed to Sarah-Kate and Dan Dineen, while the vineyard continued to be managed by viticulturist Timbo Deaker. Additional Pinot Noir and Chardonnay were planted in 2024. The established vineyard occupies approximately eight hectares; the 2024 planting added a further 1.5 hectares of young vines.

Site and soils

Clos Ostler lies within the Waitaki Valley North Otago geographical indication. The region occupies a narrow area along the southern side of the Waitaki River and is influenced by both the inland climate of Otago and cooler air arriving from the Pacific Ocean. Its vineyards experience a comparatively long growing season, low heat accumulation and recurrent spring-frost risk.

The vineyard occupies a north-facing escarpment formed from marine sedimentary material deposited when the area was beneath the sea. Uplift and erosion subsequently exposed limestone along the lower Waitaki Valley. New Zealand Winegrowers dates the former seabed from which the limestone developed to approximately 38 million years ago.

The vineyard soils have been mapped within the New Zealand Soil Classification as Rendzic Melanic soils. Rendzic Melanic soils develop where limestone, calcareous sedimentary rock or calcareous rock debris occurs at shallow depth. Melanic soils collectively cover about 1 per cent of New Zealand and occur in association with lime-rich or mafic parent materials.

Soil analyses published by the estate recorded a pH of 6.9, total base saturation of 97 per cent and calcium saturation of 89 per cent in the Ostler Block. In the Kairos Block, the corresponding results were pH 6.7, base saturation of 93 per cent and calcium saturation of 83 per cent. Base saturation measures the proportion of a soil's cation-exchange capacity occupied by the base cations calcium, magnesium, potassium and sodium; calcium saturation records the proportion occupied specifically by calcium. These values therefore indicate a strongly calcium-dominated exchange complex, rather than the percentage of calcium carbonate by mass in the soil.

The soils are free-draining and relatively low in fertility. Their chemical composition is considered alongside variation in soil depth, aspect, wind exposure and water availability when vineyard parcels are assessed.

Viticulture and production

Pinot Noir is the principal variety. Planting material includes Dijon clones 115, 667 and 777, UCD6, and the New Zealand Abel selection. The grapes are harvested by hand, with vineyard parcels and clonal selections picked and fermented separately. Individual lots remain separate during maturation before the final wines are assembled.

The producer makes three Pinot Noir bottlings from the same monopole. Caroline's Pinot Noir, first made during the vineyard's original ownership, draws on several clonal and vineyard components. EOS Pinot Noir was introduced with the 2022 vintage and is selected from lots intended for elegant perfume and longer maturation in bottle. Waitaki Pinot Noir draws on clones chosen for freshness and produced in selected vintages. Audrey's Pinot Gris and a barrel-fermented Chardonnay provide two mineral white-wine expressions of the site.

Winemaking details vary by wine and vintage. Under the current ownership, blending decisions are generally made after approximately ten months of maturation. Tight-grain French oak from Tonnellerie Taransaud has been used since 2022, with the proportion of new oak determined separately for each wine and vintage.

Recognition

Caroline's Pinot Noir received International Wine Challenge gold medals for six consecutive vintages beginning with 2010. At the 2025 competition, the 2021 vintage received the New Zealand Red Wine Trophy, New Zealand Pinot Noir Trophy and North Otago Pinot Noir Trophy, in addition to a gold medal. New Zealand Winegrower described it as the final vintage made before the 2021 sale of the business.

EOS Pinot Noir 2022, the first vintage of that wine, received 97 points and a Platinum medal at the 2026 Decanter World Wine Awards. In its report on the results, Decanter identified Clos Ostler as the first Waitaki Valley producer to receive a Platinum medal at the competition.

Wine writer Jasper Morris has described Clos Ostler as one of the pioneering Waitaki producers and has reviewed several vintages of its Pinot Noir. Reviewing Caroline's Pinot Noir 2021 for JancisRobinson.com, Richard Hemming described it as "one of those wines that stops you in your tracks" and placed it among the strongest Pinot Noirs in a broad New Zealand tasting. Together, the long-running Caroline's bottling and the later EOS selection have given the vineyard recognition across successive phases of its development.

Place within the Waitaki Valley

Clos Ostler's development has closely paralleled that of the Waitaki Valley wine region. The vineyard was planted one year after the valley's first recorded commercial plantings; the Waitaki Valley North Otago geographical indication was registered in 2018 and remains one of New Zealand's smallest by planted area. New Zealand Winegrowers and Inside Burgundy have both identified Clos Ostler among the producers that established the region's early reputation. Its continuing production from one bounded vineyard provides a record of more than two decades from a site selected before the regional style or commercial prospects of the Waitaki had been established.

Clos Ostler

Bron en licentie