Like many of those who pioneered Australia’s emerging winemaking regions in the 1960s and 70s, Kevin and Diana weren’t winemakers by training. Although Kevin’s grandfather had produced a wine known as ‘Punchbowl’ that sold well throughout Western Australia, Kevin’s father was teetotal, and sold off the vineyards. Kevin trained as a doctor during the 1940s and began practicing in Busselton, just north of Margaret River, shortly after the end of World War II.

The journey Kevin and his wife, Diana, took into the world of wine was an indirect one. They’d bought some land in Wilyabrup and, while Kevin commuted to work in Busselton, Diana stayed home on the farm, raising sheep, cattle and six children. At a point where they were considering planting lupins on the property, they were given advice by Dr John Gladstones, the scientist widely credited for first identifying Margaret River as a promising region for wine, that they should consider planting Cabernet Sauvignon instead.

The Cullens not only didn’t need much persuading, they were clearly natural winemakers too. Within a decade of their first vintage, Diana’s wines had won gold medals and trophies at wine shows around Australia. She and Kevin travelled and tasted extensively, using their experiences to further refine their skills and build their winery’s reputation for excellence. In the late 1980s, Diana passed on the winemaking baton to her daughter Vanya, who came to London recently to host a vertical tasting of key vintages of Diana Madeline (see tasting notes below). The tasting was a double celebration of not only the 100th anniversary of Diana Cullen’s birth but also of the 50th anniversary of the plantation of the Cabernet Sauvignon vines that make up the cuvee’s backbone (another tribute to Diana, who much preferred blended wines to pure Cabernet Sauvignon).

Vanya, recently awarded the Order of Australia (OAM) in the King’s Birthday Honours for services to viticulture and oenology, took the opportunity to delve deep into how her approach to grape growing and winemaking has evolved over the past three decades. Cullen was one of the first wineries in Australia to espouse biodynamics in 2004, a move Vanya says was no great watershed, ‘The biggest shift was the conversion to organic rather than the move from organics to biodynamics’, she says. The Cullen belief in biodynamics is profound and informs every action taken in the vineyards and the winery – from harvesting decisions to the choice of oak barrels (most of which are also produced biodynamically). ‘The biodynamic planetary calendar is how we time our work in the vineyard and winery wherever we can,’ says Vanya. ‘It’s about working nature and learning all the time – having that land-to-sky feeling in the day-to-day.’

The minute attention to detail and the intimate knowledge of the vineyards required by biodynamic production is underpinned by research and observation. For instance, many years of trellising experiments in the vineyards revealed that the Scott Henry system produces the ideal tannins in Cabernet Sauvignon. ‘We found that this trellis gives the berries exposure to sunlight immediately after fruit set, starting the process of phenolic ripening early, facilitating fine, ripe tannins,’ explains Vanya.

Those tannins are then handled with care and precision in the winery to avoid overextraction. ‘We’ve never heavily worked our wines,’ says Vanya, ‘but in 2017 we made a decision to use fruit tannins as structure rather than oak, and hence have been moving towards the use of large-format oak puncheons rather than small barriques.’ Hand in hand with that has been an increasing tendency to mature a proportion of the wine in terracotta amphorae. ‘It’s only a small component, says Vanya, ‘but they give the wine increased structure from the fruit tannins, increasing the length on the palate – which is just what we want from our beautiful biodynamic Cabernet Sauvignon.’