This decision is made with the help of neutron probes - sensors deep in the soil which monitor water levels and tell the vineyard manager when to turn on the tap. The Koonunga Hill vineyard contributes to Penfolds red wines such as Grange, Bin 707 Cabernet Sauvignon, Bin 389 Cabernet, Shiraz, St Henri Shiraz and Kalimna Bin 28 Shiraz. Average yield is between four and six tonnes per hectare or about 1.5 to 2.5 tons per acre. The vineyards are now established and contribute to a number of premium wines, including the Clare Estate red, a blend of Merlot, Malbec, Cabernet Sauvignon and Cabernet Franc, and the Clare Estate Chardonnay. A further 50ha of organic vineyard will be planted over the next two years, taking total area of the Clare Estate vineyards to 180ha by the end of 1995.
Summers are warm to hot and dry, with quite high evaporation.
This reduces the risk of vine disease and pest problems and explains the choice of the Clare Estate for organic viticulture. Most of the vineyard is mechanically pruned and harvested and the entire vineyard is set up on a drip irrigation system providing supplementary water when necessary in summer. Harvest generally begins in mid-February and finishes at the end of March or early April.