Touraine is the district at the very heart of France's Loire Valley wine region, both geographically and in terms of production. Named after the city of Tours at its center, it follows the course of the Loire river for roughly 60 miles (100km), from Blois and Mesland in the east to Chinon and Bourgueil in the west.
Touraine has its own generic regional appellation (simply called Touraine) which covers the entire district, as well as several titles that are more specific in terms of both location and wine style. These range from the dry, fruity reds of Saint-Nicolas de Bourgueil to the diverse whites of Vouvray and Montlouis. The Cheverny and Cour-Cheverny zones, trapped in the hinterland between Tours and Orleans, are often grouped into the wider Touraine area on maps and wine lists.
Wines made under the Touraine regional appellation may be red, white or rosé, and each color also comes in sparkling variants. The still red wines are made principally from Gamay, Cabernet Franc and Malbec (known here as Cot), with smaller proportions of Cabernet Sauvignon and Pinot Noir. Their white counterparts, which make up roughly half of all Touraine wines, are dominated by 'Sauvignon' – a combination of Sauvignon Blanc and (less commonly) Sauvignon Gris. Touraine roses, which constitute less than 10% of production, are created from the same varieties as the reds with the addition of the Loire's less-favored Grolleau Noir and Pineau d'Aunis, and even Pinot Meunier.
The Touraine district is located a full 140 miles (226km) from the Atlantic Ocean, and the same from the northern Massif Central hills of central France. As a result, the climate here falls somewhere between maritime and continental. There is a noticeable difference, however, between the cold, drier winters in the district's eastern edge and those in the west, which tend to be slightly wetter and more temperate. In summer, the slow-moving waters of the Loire do little to cool the Touraine vineyards; this region is known for its hot, torpid summer days.
Throughout the Touraine, the better vineyard sites are those blessed with free-draining soils rich in tuffeau. Tuffeau is the calcareous rock for which this part of the Loire Valley is famous. It was used as the building material for most the valley's famous chateaux, and tuffeau caves proved perfect for long-term wine storage and ageing. There are various etymologies and confusions surrounding tuffeau, tuff and tufa, but what is clear is that the rock here in the central Loire is a form of soft, porous limestone formed during the Turonian age (named after Tours) of the Cretaceous period, roughly 90 million years ago. Its two key forms: chalkier, firmer tuffeau blanc and softer, sandier tuffeau jaune. The former is used for building chateaux, while the latter underpins the Loire's finest Cabernet Franc vineyards, in Saumur. Both types are geologically distinct from the volcanic rock on which the vineyards of Tufo, southern Italy, are planted (see Greco di Tufo).