The Furstentum Grand Cru lies at 400m altitude, facing due south. It is one of the last remaining vestiges of the sub-Mediterranean era that Alsace experienced. The soil is very stony and drains well because the calcareous bedrock breaks through.
The grains nobles are picked grape by grape during successive passages through the vineyard. They are in a shrivelled, concentrated state at the moment of picking, having been affected by noble rot (botrytis cinerea). This concentration masks the varietal characteristics somewhat, yet gives the wine exceptional complexity and power.
The juice is delicately extracted in an air-bag press. The slow, gentle pressing avoids crushing the stalks and pips. The fermentation proceeds at a controlled temperature in stainless-steel vats. It gets under way of its own accord thanks to the natural yeast found on the grape skins. As for the botrytis cinerea, it concentrates the grapes' sugar levels (80 to 150 g/l of residual sugar) and acidity. The resulting sweet wine is complex and very concentrated, and has enormous ageing potential.