Château Rieussec, Sauternes Premier Cru, 2009

Château Rieussec is a sweet white wine ranked as Premier Cru Classé (French, “First Growth”) in the original Bordeaux Wine Official Classification of 1855. Belonging to the Sauternes appellation in Gironde, in the region of Graves, the winery is located in the commune of Fargues.

The Rieussec estate was the property of the monks of Carmes de Langon in the 18th century. Following the French revolution, church property was confiscated by the state and auctioned off. In about 1790, Rieussec was bought in this fashion by a Mr. Marheilhac, who at this time was also the owner of Château La Louvière in Léognan.

The owner at the time of the 1855 classification, when Rieussec was classified a first growth, was a Mr. Mayne. After that, Rieussec had a long succession of owners: Charles Crepin bought in around 1870, Paul Defolie in 1892, Mr. Edgar Bannel a well known banker of Bordeaux in 1907, the Gasqueton family (also owners of Château Calon-Ségur in Saint Estèphe), the American P. F. Berry (brother-in-law of the Vicomte de Bouzet) during the war, Mr. Balaresque in 1957 and Albert Vuillier in 1971.

In 1984, Rieussec was bought by Domaines Barons de Rothschild, the owners of Château Lafite Rothschild. The Rothschilds invested in a new cellar in 1989, and strove to increase quality by better selection of the grapes, which also led to reduced production in the 1990s. In the 1993 vintage, one of three difficult Bordeaux vintages in a row, no Château Rieussec grand vin was produced at all out of quality considerations. One of the more recent recognitions for quality was when Château Rieussec 2001 was selected as Wine Spectator's Wine of the Year in 2004.

The vineyards of Château Rieussec convers 93 hectares (230 acres) and border on those of Château d'Yquem in the west. They are planted to 90% Sémillon, 7% Sauvignon and 3% Muscadelle.

Four wines are produced, of which three from the Sauternes appellation: the classified growth Château Rieussec, the second wine Carmes de Rieussec, and Château de Cosse. Furthermore, a dry white wine from the Bordeaux AOC, is produced under the name « R » de Rieussec, using a blend of Sémillon and Sauvignon Blanc, and 20% new oak.

Château Rieussec is aged from 16 to 26 months in barrel, depending on the vintage, typically using 55% new barrels.

Average total production is around 10 000 cases annually, of which about 6 000 cases Château Rieussec. There was no production in 1993 and half the average production in 2000.

Sauternes, 40 miles (65km) south of Bordeaux city, is a village famous for its high-quality sweet wines. Although some wineries here produce dry wines, they sell them under appellations other than the sweet-specific Sauternes appellation. The village is surrounded on all sides by vineyards, the best of which produce some of the world's most prestigious, long-lived and expensive dessert wines. A half-bottle of top-quality, aged Sauternes wine from a good vintage can command prices in excess of $1000.

The classic Sauternes wine has an intense golden colour (darker than most other dessert wines), which turns a deep amber as it ages in bottle. The aromas include blossom and stone fruit, with a hint of honeysuckle – the trademark of botrytized wines. The best wines balance sweetness with acidity, concentration with freshness, and power with elegance.

Sauternes' wines are made mostly from the Semillon grape variety, which accounts for about eight in every 10 vines in the local vineyards. Sauvignon Blanc accounts for much of the remaining vineyard area and is the dominant variety in just a small handful of Sauternes wines. Semillon forms a broad, well-structured base with aromas of beeswax and apricot, while Sauvignon Blanc brings its trademark herbal aromatics and sufficient acidity to keep the resulting wine fresh rather than palate-cloying. This pair (which are sometimes complemented by a tiny amount of Muscadelle and Sauvignon Gris) have become the preferred varieties here not only because they are also used to make Bordeaux's dry whites, but because of their susceptibility to a particular kind of fungus, Botrytis cinerea (often just botrytis).

Other than yeasts, without which grape juice could not ferment into wine, one might not expect a fungus to play a key role in winemaking. And yet the distinctive Sauternes wine style is entirely dependent on this particular fungus strain. Under adverse conditions, Botrytis cinerea causes grapes to rot and disintegrate, further exposing their flesh and juice to all manner of other fungi and bacteria. In this form, it is known as "grey rot", and leads to sour, unpleasant aromas in wine. But when botrytis spores land on healthy grapes under favourable weather conditions, they have quite a different effect, and develop into benevolent "noble rot".

Noble rot develops most reliably in areas where morning mists, which allow the fungus to thrive, are followed by warm, dry afternoons that dry the grapes out and prevent the development of grey rot. When repeated over a number of weeks, this process gradually dries the grapes, reducing their water content and naturally concentrating their sugars and flavour compounds. The result is intensely sweet, flavour-rich juice. In autumn, Sauternes and its neighbours Barsac, Bommes, Fargues and Preignac have exactly these climatic conditions, thanks to the warming and cooling of air around the nearby River Ciron.

The Sauternes appellation laws state that grapes may be picked only when their must weight reaches 221 grams per litre (the minimum for regular, dry Bordeaux Blanc wines is just 162g/L). Because not all these abundant sugars are fermented into alcohol, the finished wine contains naturally high levels of residual sugar. In good vintages, nature needs no help getting grapes to such high levels of sweetness, but in poor vintages, winemakers turn to cryoextraction and even chaptalisation to achieve this. Cryoextraction involves freezing the grapes before they are pressed, which reduces the amount of water in the resulting juice. Chaptalisation – the addition of sugar or artificially concentrated grape juice – is permitted only in poor vintages and, even then, only to a limited extent.