The volcanic KaiserstuhlIn the Tertiary era, some 19 to 16 million years ago, the volcanic section of the Kaiserstuhl emerged. This period represents the high point and the final flowering of volcanic activity here in the Upper Rhine region, activity which had been going on for some 30 million years and evidence of which is still visible today in the form of deeply eroded volcanic chimneys. Magma had emerged about 25 million years ago, at the end of the Oligocene era, but solidified just below the earth’s surface. Shifts in tectonic plates subsequently weakened the crust boundaries and enabled the magma to be thrust upwards by the pressure from below. Only one major volcano is still visible from that era in today’s Upper Rhine: the Kaiserstuhl. At its emergence, the Kaiserstuhl probably reached a maximum height of some 1000 metres above sea level; now, millions of years later, it boasts a peak of 556.6 metres, at the Death’s Head, or Totenkopf.
To the north of the predominantly volcanic area there is an area of sedimentary rock, much older than the igneous rock to its south, but still visible as a hill, while the sedimentary valley floor all around has sunk to a lower level.
The Blankenhornsberger Doktorgarten vineyard occupies part of the volcanic Kaiserstuhl. It exhibits no loess deposits, so the vines are growing directly on eroded volcanic soil. The blackish soil takes up the warmth of the sun in the day, and emits warmth long into the evening. The grapes ripen correspondingly quickly and fully. The Kaiserstuhl igneous soils are have a feature that we believe makes them unique in the world: there are limestone layers in the volcanic soil (identifiable by the white streaks they leave on the rock) and these contribute to our optimal growing conditions for all the major pinot varieties.