Jeffrey Grosset started in the wine game young, with a bottle of riesling tasted at the family dinner table propelling him to study agriculture and oenology at the age of 16, graduating by the time he was 21. Establishing Grosset Wines in 1981, he has become one of Australia’s most lauded winemakers – with riesling a notable specialty – but the heart of the Grosset operation has always been in evolving the work in the vineyard to make vital, pure wine that is intensely expressive of site. His Watervale Vineyard is comprised of two sections planted to quite different soils, with both underpinned by certified biodynamic farming overseen by vineyard manager Matthew O’Rourke.
The Watervale site was selected by Grosset after rigorous surveys, with the elevated, cool site – the equal highest in the subregion – having two distinct geologies separated by a fault line that resulted in two sections being planted to different varieties. The Springvale section is made up of “soft rock”, which was dedicated to riesling across three clones and 6.12 hectares, planted from 2000 to 2003.
“Springvale is a truly unique viticultural site due to its geology,” says vineyard manager Matthew O’Rourke. “The thin topsoil is made up of red loam over limestone, and, atypical for this subregion, the vines are deeply rooted in slate bedrock. There is a north-south fault line on the eastern border, limiting any expansion. This formation dates back many hundred million years. Rows are oriented to optimise sunshine. Riesling flourishes at this site.”
The Rockwood section is loam over brown rock, with fiano planted to the hardest rock, and the remaining made up of riesling (a single clone that is made into the very limited ‘G110’ release), shiraz and nero d’avola over a total of 10.89 hectares. “Rockwood, with its hard red rock and variable soils, is viticulturally the more challenging,” says O’Rourke. “In fact, its geology is very different to Springvale.”
The Watervale vineyard was certified organic in 2014, with biodynamic certification coming in 2019. The winery is also organically certified, along with the bottling facilities, which are both situated in nearby Auburn. “We are one of only two producers in the Clare Valley that are certified organic and biodynamic,” says O’Rourke. “The difference between what we do at Grosset and mainstream practices is dramatic. We want to show trade and consumers the difference – let them see how attractive and more beautiful the vineyard environment can be under organic and biodynamic certification. When the focus is on complexity, diversity and environmental stability, rather than simply on cost of production.”
Regular organic mulch applications are made under vine, which have resulted in a reduction of water due to reduced evaporation, cooler soil and increased water-holding capacity through boosting organic matter. Sheep are employed to keep grasses down in the cooler months, which also reduces soil compaction by limiting machinery passes. When biodynamic sprays are applied, gators (light utility vehicles) are favoured over tractors, while most other processes are completed by hand, from pruning to harvest.
The midrow sward is permanent, established between 2005 and 2010, with the soil no longer cultivated. Nitrogen-fixing clover and medics are mixed with perennial rye grass. Although the soil retains more moisture, this is supplemented by drip irrigation, with an advanced control system to irrigate precisely, including night watering, which limits evaporation and allows better uptake to set up the vines before the heat of the day.
O’Rourke has access to mains water and onsite bores, and though their water use has diminished over the years through retaining more moisture in the soil due to increased organic matter, permanent ground cover and mulching, he stresses that lack of water will be an ongoing issue, with the years consistently becoming drier. “We need a sustainable water solution for now and in the future,” he says. “This must be recycled water, which will not impact on the finite Murray River system.”
When the site was acquired in 2000, it was essentially barren land with a dozen or so remnant tress. Substantial plantings of native trees and shrubs have since been established. “After having planted around 15,000 trees and shrubs over the last decade in adjacent land, plus the regeneration of the Eyre Creek that flows through the property, there has been a massive increase in biodiversity. Most recently, we have been involved with the EcoVineyard’s project, planting more beneficial insectary focused shrubs,” says O’Rourke, noting that bat boxes have also been placed in eucalypts to add another layer of natural pest control.
“Establishing our organic and biodynamic practices has led to greater microbial activity and improved aeration and retention of moisture around the roots of the vines, affecting overall soil health,” says O’Rourke. “There is now a ‘sweetness’ to it, and the vineyard seems more alive. Greater species diversity facilitates natural pest and disease management.”
The conversion to biodynamics has also seen a palpable change in the wines. “All the wines have become clearer and brighter in our view,” says O’Rourke. “So, whatever the specific reasons, we believe it is due to the management of the vineyard. It feels to us as if the bright-coloured and healthy looking vine growth combined with a more integrated and connected complexity of species adds to the stability of the vineyard and overall calmness of the property. We are committed to biodynamic farming because we know it is better for our soil, vineyards and surrounds, employees and the flavour of our fruit.”