Terra Rossa Soil of the Coonawarra Wine Region and its Dazzling Reds

South Australia is home to a special terroir, one that has a very rich geological history. In it, the Coonawarra wine region is home to an incredibly famous and unique soil, terra rossa, that has catapulted it and the wines produced here into worldwide acclaim.

Meaning ‘honeysuckle’ in the Aboriginal language, Coonawarra and the terra rossa soil can be found about 236 miles southeast from Adelaide, near the Victoria border. The location and this red soil (which is the literal meaning from Italian) are what makes the wines produced here such pure joy.

Terra rossa is a reddish, clay, silty, and well-drained soil. The color comes from hematite forming over goethite. The soil forms in layers that vary in thickness, some just inches while others much larger, atop limestone and dolomite bedrock. It has neutral pH conditions and high internal drainage which make for very unique characteristics, considering most clay-based soils aren’t terribly good at natural drainage. Terra rossa soil is also found in La Mancha, Spain, but coupled with the South Australian climate, it is a perfect terroir for producing red wines.

John Riddoch, a Scottish pioneer, first planted the vines in 1890 at Yallum in South Australia. Back then, Shiraz was the most common grape variety growing in the region. It still grows and thrives in the terra rossa soil today, however it is often overshadowed by the impeccable Cabernet Sauvignon.

Terra Rossa soil

As time moved forward, a man by the name of Samuel Wynn realized the potential this small strip of terra rossa soil held and purchased the original cellars from the Riddoch family in 1951. This was a pivotal point in Australia’s wine history, one that would change the landscape of wine production for the better.

Many factors go into making a terroir the kind of success it is, and the terra rossa soil found in South Australia is indeed true tale of success. This relatively small swatch of land sits atop a shallow limestone ridge, surrounded by swampy lands on each side. It’s like a jewel in the center of the black rendzina soil just to the west of this ridge, a place with poor drainage and less favorable conditions for growing vines. Midway between, a brown rendzina produces the opposite effect but doesn’t match the greatness of terra rossa soil. This led to a number of heated disputes until Coonawarra was entered onto the Register of Protected Names.

Add to this the climate of the Coonawarra region and it’s a prime place for certain varietals to thrive. It’s only 37 miles from the sea, rendering the climate a bit similar to that of the one in the famed Bordeaux region. With around 8 inches of rainfall in the growing season from October to April and a convenient cloud cover in January that keeps the temperatures down, it’s as if nature knows not to disturb the harmony in the grapes grown here.

It’s not always easy and breezy for this wine region though. Every once in a while, spring frosts will decimate the vineyards, wiping out much of the crops. The last notable frost was in 2007, rare yet relatively destructive. Still, the region bounced back and the terra rossa soil continued to create some of the most spectacular vines anywhere.

One grape that truly shines when rising up from the terra rossa soil is Cabernet Sauvignon. For wine aficionados the world over, choosing a bottle of Cabernet Sauvignon produced in Coonawarra is something that won’t disappoint. Grown in the terra rossa soil, this grape brings forth intense flavors of plum and blackcurrant. Margaret River is also well-known in Australia for Cabernet Sauvignon but in Coonawarra with the terra rossa soil, it has a well-balanced flavor profile.

The other notable red grape growing in terra rossa soil in Coonawarra is Shiraz. It’s an utterly sublime offering, but when standing next to Cabernet Sauvignon, it almost always gets passed up. Prior to the growth of the Coonawarra wine region, the Australian wine industry produced fortified wines. Australian wines were essentially nothing to write home about until the discovery of the terra rossa soil shook things up and woke the Land Down Under up to the incredible potential it possessed.

Because of the unique limestone bed and red clay, the wines here are among the most exceptional in the country. That limestone also bodes well for white varieties like Riesling, Chardonnay, and Sauvignon Blanc, but few turn their heads for those. Hawke’s Bay steals the show with Sauvignon Blanc anyway, and with such divine Cabernet Sauvignon and Shiraz flowing from Coonawarra, these reds absolutely steal the show. Perhaps you’ll ponder just how severe an impact this all had for the island continent’s wine industry while you pour yourself a glass of Cabernet Sauvignon or Shiraz hailing from one of the wonderful wineries in Coonawarra. Perhaps you’ll trot it out as interesting trivia while you sip and savor the richness of the flavors you’ll uncork in every bottle.