The soils are predominantly clay, rich in iron and manganese oxides, and overlays ancient weathered rock. Wind and soil create a low vigour growing environment where grape vines struggle and produce small but concentrated yields of ripe fruit with intense flavours.
The surrounding warm sea currents boost the temperature of the island by up to 2 degrees centigrade, while the afternoon sea breezes reduce the effects of excessive heat buildup, giving Waiheke Island one of the world's lowest diurnal temperature ranges for growing wine grapes. Waiheke's warm days (up to 32 degrees C) and mild nights maintain the amount and duration of temperature required to respire away both malic acid and methoxypyrazine.
The Obsidian Vineyard is positioned in the Onetangi basin, an amphitheatre-like valley with a complex array of aspects.
Block 1 - The original vineyard, is planted with a NW aspect and with the initial intent of a lyre system. The vineyard has higher plant density with a wide drivable row, alternating with a narrow row, driving the roots of the vines closer together. This block is planted with the original plantings of five different Bordeaux varieties.
Block 2 - Combines the original “North Face” (NE) and “Saddle” (NE-SW) blocks. The vines on the north face directly overlook the wetlands in the valley and are a backdrop to the cellar door.
Block 3 – “The Ridge” is completely NE facing with all vines planted on steep slopes ranging from 10 degrees to 35 degrees – no flat areas or south-facing slopes.
Block 4 – “The Terraces” is planted with Syrah in the style of the Northern Rhône. Staked at a high density and pruned in goblet style. These vines are extremely low-yielding and NW-facing.
An aerial photograph of the Obsidian vineyard in 1995 by Aerial Surveys Ltd