The red grape variety is a new variety between Blauer Portugieser x Färbertraube (but the father variety is not clear). Synonyms are Schlagerrebe, Schlehenbeeriger and Schwarze Kadarka. The cross was made around 1940 by the Austrian breeder Michael Schlager at the Styrian Viticulture Institute, after which it was named Silberberg after whom it was named. Schlager was a teacher at Silberberg and director of the institute from 1938 to 1945. The breeding goal was to create a "purely German vine without any French influence". It produces dark-coloured red wines with a fruity forest berry aroma. Due to the low yield, the variety did not ultimately establish itself. However, it is permitted as a local speciality in Styria(Austria) for quality wines. In 2016, however, no stock was recorded (Kym Anderson).
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