Great insights from Blake Leja, Wanda Cole-Nicholson, Brandon Ford and Karl Kazaks last week on the 1er cru vineyards of Beaune AOP. Thanks for your contributions!
This week: Barossa
What are the sub regions and the major geographic features? What impacts do these have on the wines?
The GI's of Barossa are Barossa Valley and Eden Valley GI's. The Barossa Ranges is the major natural feature. This Range is the main source for the North Para River as well as well as Jacob's Creek. The Barossa Ranges are east of the Barossa Valley and are very windy and cool. Allowing for varieties such as Riesling to be planted. Higher elevation assists in keeping acid levels elevated.
In support of your statements: Eden valley, which is to the East of the Barossa Valley and of a higher elevation , riesling is indeed the number 1 planted grapes (over 35%). In the Barossa Valley where the altitude is slightly lower and average temperature warmer, Shiraz is the number planted grapes (over 55%) and riesling is not significant here.
I believe I may have awkwardly worded my response. I was not suggesting Barossa Valley grows Riesling. My statement was claiming that due to the elevation of the Barossa Ranges. Riesling is grown there because of the elevation.
Beyond simply elevation, the Barossa Ranges create a fairly diverse lanscape of slope angles and aspects. There are valleys galore and transverse cuts in a multitude of directions. Some hills roll on, ,while others get steeper. In each GI, there are vines planted in almost every direction. Southeast facing hills may get something like Chardonnay, while the north north facing slope just over the ridge might get a rich Cabernet. Due to runoof and erosion caused by the Ranges, Soil depth varies throughout, as it does in other regions with elevation changes. Here, though not a hard and fast rule, the deeper soils are thought to give a bit more acidicty than those that are shallow.
In addition to what has been said I would also like to add the sub region High Eden within Eden Valley. This being the highest point in Eden Valley is cool, windy with poor soils contributing to a more mineral, leaner style of wine. Chardonnay, Riesling, and Shiraz are the key players here.
Another point of Barossa that should be noted is that prevalence of older vines: some such as the centenarian and ancestor designated being 100 and 125 years old respectively. The older roots digging deeper into the soils picking up many trace elements lending a much more mature, rich, and complex character to the wine. Particularly to shiraz bringing much more minerality to balance out the dominating fruit character that Barossa tends to possess.