Coonawarra, wine region, most geographical indication at downunder

Coonawarra is a wine region, on the Limestone Coast of South Australia, that is known for the Cabernet Sauvignon wines produced on its "terra rossa" soil. Coonawarra is an Aboriginal word meaning "Honeysuckle". It is about 380 km southeast of Adelaide, close to the border with Victoria. The first vines were planted by John Riddoch at Yallum, South Australia in 1890. Only the Redman family of Rouge Homme continued to produce table wine during this period, during which Shiraz was the main grape variety grown.  Fortunes changed when Samuel Wynn recognised the potential of the strip of terra rossa soil, and bought the original Riddoch cellars in 1951. Led by Wynns and Penfolds, Coonawarra was to play a leading role in the transformation of the Australian wine industry as it changed from making fortified wines to conventional table wines. Coonawarra's terra rossa soil is one of the most famous terroirs in the New World, covering an area of just 15 km x 2 km north of Penola. It lies on a shallow limestone ridge, raising it above the swampy land either side - it is no coincidence that the Riddoch Highway follows this ridge as carters sought the firmest ground in times past. This special bright red soil is clearly visible on an aerial photo. To the west of the ridge lies black rendzina soil which is poorly drained, and so is much less favourable for vines. There is also a 'transitional', or brown rendzina, soil which grows vines quite successfully. This geological complexity led to many disputes during an eight year period before Coonawarra was entered on the Register of Protected Names. At least one vineyard (belonging to Penola High School) has the boundary pass through the middle. Being just 60 km from the sea, Coonawarra has a somewhat maritime climate not dissimilar to Bordeaux. During the growing season, there is just 219mm rainfall (Oct-Apr), out of 585mm annually. Extensive cloud cover keeps the temperature down to 19.1°C in January. Coonawarra is synonymous with classy Cabernet Sauvignon, full of plum and blackcurrant fruit. So much so, that successes with other grape varieties is overlooked. In the early days Shiraz was the most widely-planted grape, and it produces some star wines such as Wynns Coonawarra Estate Michael Shiraz (formerly Michael Hermitage). The limestone geology also suits Chardonnay, Riesling, and Sauvignon Blanc. Coonawarra has a membership organisation for wineries, the Coonawarra Vignerons Association. Some of the wineries with cellar doors include Wynns Coonawarra Estate. Other wineries who use fruit from the Coonawarra include Yalumba and Penfolds.