Sauvignon Blanc and flint, Pouilly-sur-Loire© Chateau de Tracy Pouilly-Fumé – a dry white wine made from Sauvignon Blanc grapes – is one of the Loire Valley's most revered wines. It is rivaled in this regard only by Sancerre, just the other side of the Loire River, and perhaps Vouvray. The Pouilly-Fumé appellation was created in 1937 originally as Blanc Fumé de Pouilly. The village's Chasselas-based wines gained the Pouilly-sur-Loire title at the same time. The Pouilly-Fumé name is composed of two parts. 'Pouilly' is short for Pouilly-sur-Loire, the village the wines come from. 'Fume' is short for Blanc Fumé, which is the local nickname for Sauvignon Blanc. It is sometimes understandably confused with Pouilly-Fuissé a Chardonnay-based wine from southern Burgundy. The fumé in Blanc is French for 'smoky'. It denotes the struck gunflint aroma that characterizes the local Sauvignon Blanc wines. This distinctive smell is often referred to as pierre à fusil, which means 'flint' literally 'rifle stone'. It is a key point of differentiation for Pouilly-Fumé's winemakers, and a source of great local pride. Aromatically speaking, Pouilly-Fumé wines are some of France's most vivacious, although they are typically less pungent than the notoriously grassy styles of Sauvignon Blanc produced in New Zealand particularly Marlborough. They have a vibrant streak of green fruit aromas lime, green apple, gooseberry supported by mineral aromas of wet wool, slate and smoky flint. The official Pouilly-Fumé viticultural area encompasses seven parishes on the right bank of the Loire. These run from Mesves-sur-Loire in the south to Saint-Martin-sur-Nohain, a few miles to the north. These villages are technically in Burgundy, although Pouilly-Fumé remains a quintessentially 'Loire Valley' wine. In true French style, the local terroir is given the credit for Pouilly-Fumé's very particular aroma and flavor. It has been intricately studied and mapped. The key soil types are divided into limestone, marlstone, clays of various compositions and the all-important flint. Limestone and flint are the most important components. Both have excellent heat-retention and light-reflecting properties and help the vines to achieve optimal ripeness in the cool growing season here. Local winemaking legend Didier Dagueneau even named one of his top bottlings 'Silex'. This is a mix of silica, limestone, and flinty clay. Until phylloxera wiped out vast tracts of vines in the 1860s, the vineyards around Pouilly-sur-Loire grew mostly Gamay and Pinot Noir. When the solution to the phylloxera epidemic was identified – grafting European vines onto American rootstocks – Sauvignon Blanc proved to be more responsive to grafting than these red varieties. Thus Sauvignon came to be Pouilly's most widely planted grape variety. The 1970s and 1980s saw Pouilly-Fumé's popularity increase greatly, along with the total vineyard area. Plantings of Sauvignon Blanc vines in the area rose at the cost of the Chasselas. There are now around 1325 hectares 3275 acres of Pouilly-Fumé vines in 2005. This compares with around 30ha 74 acres of Chasselas. Vineyard yields are set from 6500 to 7500 liters per hectare. Planting density must be at least 6000 vines per hectare. Average annual production over the last five years is around 7 million liters million US gallons. The 1980s saw a number of producers introducing an element of oak into their Pouilly-Fumé wines, either via barrel fermentation or barrel maturation, or both. The resulting wines were aromatically and texturally more complex than the standard unoaked wines, and also better-suited for mid-term cellaring. Most modern Pouilly-Fumé will improve in bottle for between three and six years.