Definition - What does Clay Soil mean?
Clay is another variation of soil used in the world of viticulture for growing high-quality grapes. There are quite a few types of clay soils, each with its own set of characteristics. Calcareous, Marl and Albarese are very well-known types of limestone-based Clay soils. Clay soils tend to retain a lot of water and are recognized for their superior nutrient and mineral properties. Some of the world's boldest wines are made from grapes grown in Clay soil.
WineFrog explains Clay Soil
Clay soil is made up of tiny particles that tend to store water for prolonged periods of time. This increases the tendency of the soil to remain cooler, the grape vines greatly benefit from this aspect in harsh weather conditions and when they are not watered.
The famous red wines produced from Clay soils include Cabernet Sauvignon from Rioja, Spain, the highly acclaimed Pinot Noir from Burgundy, the muscular Sangiovese from Chianti and last but not least the widely recognized Shiraz from Barossa, Australia.