When our wines say Barossa Valley on the label you are OK so buying a NV wine is not a risk. Glug has large stock levels of wine in barrel which is the best way for storage. A portion of this we like to freshen up and age, freshen up and further age and then re-blend. This is the evolution behind the idea of releasing three Barossa Valley wines which are versions of blending Mataro and Shiraz of different vintages.
I look back a few decades to the time Barossa wineries were puzzled when I asked for Mataro. Now at times we buy too much. Mataro has been the backbone of many Barossa Shiraz for decades because it blends well with Shiraz. It was used because there was so much planted for the long-ago fortified business, and it had to go somewhere. Then the penny dropped that it was a super-premium variety and the aged vines were of immense value. Glug is very fond of Mataro.