Tuffau is a soil type described by Tom Stevenson (2011) as ‘a buff-coloured, sandstone-rich, otherwise chalky limestone as found in the Loire, particularly around Touraine, and used in the construction of many of its châteaux.’
Bibliography
Tom Stevenson (2011) The Sotheby’s Wine Encyclopedia 5th Edition by Tom Stevenson (Dorling Kindersley, 2011), p.17-19.