Bordeaux wine almost universally used. Chaptalization is permitted, and is fairly common-place. Fermentation then takes place, usually in temperature controlled stainless steel vats. Next the must is pressed and transferred to barriques (in most cases) for a period of ageing (commonly a year). The traditional Bordeaux barrique is a 225 litre oak barrel. At some point between pressing and bottling the wine is blended. This is an integral part of the Bordeaux wine making process, as scarcely any Bordeaux wines are varietals; wine from different grape varieties is mixed together, depending on the vintage conditions, so as to produce a wine in
Margaret River (wine region) with only 200 millimetres of the annual 1160 millimetres falling between October and April. The low diurnal and seasonal temperature range means an unusually even accumulation of warmth. Overall the climate is similar to that of Bordeaux in a dry vintage. Although the region produces just three percent of total Australian grape production, it produces over 20 percent of Australia's premium wine market. The principal grape varieties are fairly evenly split between red and white; Cabernet Sauvignon, Chardonnay, Sauvignon blanc, Sémillon, Shiraz, Merlot, Chenin blanc and Verdelho. There are no official Margaret River subregions, although in 1999 viticultural scientist Dr