With years of experience in entertainment management and marketing, Mills moved to Healesville with his young children and built a house. Thirty years later, he has had primary involvement in vineyards across the Yarra Valley, and has worked at Boat O’Craigo for ten years so far. The vineyard produces grapes from two distinct sites: Healesville and Kangaroo Ground. According to Mills, the Healesville site has “alluvial soils and remnants of riverbeds and rocky alluvial reefs”, he says. It’s “southerly aspect and climate is very cool and wet” and is “suited to our white and most pinot varieties”, he says. While this climate and soil yields delicious results, the focus of this article centres around Boat O’Craigo’s other site and the unique properties of its soil. It isn’t every day that a vineyard is grown on volcanic soil, after all. And so, let us continue with this fascinating thread of complex viticulture and see where it takes us, shall we?

ABUNDANT ACREAGE

To begin, we must first dissect the components of volcanic soil and why its special properties make it prime acreage for grape growing. “Kangaroo Ground is perched high on an extinct volcano with a capping of black volcanic soil and dark brown clay with floating basalt subsoil,” says Mills. It is the ideal location for Boat O’Craigo’s red wines.

Part of what makes the volcanic soil at Kangaroo Ground so intriguing is its capability to grow grape varieties, such as grenache, that would not be considered feasible in cool climate environments. “The black soil creates a warming [effect], which allows us even in difficult wet seasons to ripen our reds like no other site in the Yarra Valley,” explains Mills. This includes shiraz, cabernet sauvignon, grenache, gamay, and two trial clones of pinots that, according to Mills, have shown “outstanding results”. The properties of the soil produce “intense flavours and colour and balance,” which contribute to the uniqueness of this particular area. While Boat O’Craigo have deemed this area the ideal place for its red varieties, Mills believes that he could grow “almost any varieties of grapes on the Kangaroo Ground site”. This is in contrast to the Healesville site, where varieties such as late ripening reds cannot grow. This means that Boat O’Craigo has the best of both worlds, and has the freedom to produce a vast range of wines for its guests.

RICHNESS UNLIKE ANY OTHER

The Yarra Valley has a long and rich history as Victoria’s first wine-growing district, which dates back nearly 180 years. Led by early settlers, the region continues to thrive to this very day. According to Mills, Boat O’Craigo has the only vineyard in the Yarra Valley with black volcanic soil. “Neighbouring properties would see some benefits, but being that we are positioned on the highest point of the extinct volcano, the soil here is at its best,” he says. “Other Yarra Valley sub-regions have red or orange volcanic soil,” he further explains.

When it comes to what the soil contributes to the wines it yields, the explanation is quite scientific. “There are numerous benefits of [Kangaroo Ground],” Mills says. “The black cap of approximately 300mm is nutrient rich. When wet, this cap is very plastic-like; when dry, [it is] crumbly and firm, providing a protective layer,” he continues. It is because of the conditions of the soil that the hill remains sturdy, even to this day, with no risk of erosion, root compactions or wet feet, as drainage is optimal. The soil’s mulch-like consistency “provides warmth during later ripening periods and protection for the subsoil” during cool, wet periods. The mineral-rich subsoil and its warming components imparts ripeness and maintains balance and acidity.