In Bunn's Vineyard, the Shiraz and Cabernet Sauvignon vines are grown without the use of chemicals to produce low yields of very concentrated grapes, using only organic and biodynamic preparations, which greatly enhance soil biology. This leads to vines which are disease resistant and wines which have a natural purity and stability and complex flavour profile.

Because of the cool climate, the grapes are harvested, typically in the second half of April when flavour and tannins are at full ripeness and the weather is favourable. They are transferred to the on-site winery and simply destemmed and crushed into small open beeswax lined fermenters. No additions of any kind are made at this, or any other stage in the process. Wines that have mutli-dimensional aromatic and complex flavour profiles can then be created from the intense fruit.

The fermentation begins spontaneously from wild yeast and proceeds for several days during which time the cap of skins is plunged by hand. While still actively fermenting, the tanks are emptied, the skins are basket pressed and the wine transferred directly to oak barriques where the fermentation runs to completion over the next few months.

French oak barriques are used for maturation with about 10% new each year. The wine stays in contact with the fine lees for the first twelve months and is racked once prior to bottling. It is not fined or filtered and no sulphur dioxide is added.