Emigrated from Provence to Oz and SA, then got mixed up with semillon and the varying nomenclatures.
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This from Wiki, most of which is very similar to JR in the OCW.
Crouchen or Crouchen Blanc is a variety of white grape. It has its origins in France, although it is now rarely grown there. Instead, it is more commonly found in Australia, where it is often referred to as "Clare Riesling", and in South Africa, where it is often called "Cape Riesling", "Paarl Riesling" or simply, "Riesling".
The wines made from Crouchen are generally not of a high quality and despite the confusion caused by it often being referred to as "Riesling". It is distinctly different to Rhine Riesling or Weisser Riesling.
SynonymsCrouchen is also known under the synonyms Basque, Cape Riesling, Cheri Cerratia, Clare Riesling, Cougnet, Crochenta, Crouchen Blanc, Cruchen, Cruchen Blanc, Cruchenta, Cruchenton Blanc, Grand Blanc, Kaapse Riesling, Messanges Blanc, Navarre Blanc, Paarl Riesling, Riesling, Riesling Vert, S. A. Riesling, Sable Blanc, Sales Blanc, Trouchet Blanc, and Zurizerratia.