Keuper is soil type described by Tom Stevenson (2011), a term ‘often used when discussing wines in Alsace, Keuper is a stratigraphic name for the Upper (younger) Triassic period and can mean marl (varicoloured, saliferous grey, or gypsiferous grey) or limestone (ammonoid).’ It is supposed to have good retention of solar heat.

Karl-Heinz Wehrheim says ‘Keuper is the youngest Triassic and a river sediment. It is an excellent soil for Chardonnay and Pinot Blanc because these varieties like the balanced water and nutrient supply. Keuper is a heavy and rich soil, with a high clay and loam content particularly suitable for Burgundy grape varieties.’

Bibliography

Tom Stevenson (2011) The Sotheby’s Wine Encyclopedia 5th Edition by Tom Stevenson (Dorling Kindersley, 2011), p.17-19.