The special distinction of this region of 1,767 ha/4,364 acres embedded within the Graves district south of bordeaux is that it is dedicated, in a way unmatched by any other wine region, to the production of unfortified, sweet, white wine. In Germany or Alsace, say, where superlative sweet wines are occasionally made, such wines are the exception rather than the rule, and emerge from vines that more usually produce much drier wines. In Sauternes the situation is quite different. The appellation is reserved for wines from five communes that must adhere to regulations stipulating minimum levels of alcoholic strength (13%) and a tasting test that requires the wine to taste sweet. Sémillon, Sauvignon Blanc, Sauvignon Gris, and Muscadelle are responsible but Sémillon is the principal grape, because it is especially susceptible to noble rot, and it accounts for about 80% of a typical estate’s encépagement. Sauvignon often attracts noble rot earlier than Sémillon, and its naturally high acidity can give the wine a freshness that balances the richer, broader flavours of Sémillon. Muscadelle’s contribution is mostly aromatic, but its viticultural frailty leads many growers to find it more trouble than it is worth. No one is exactly sure when sweet wine production became the norm here. The style was well entrenched by the late 18th century, when Thomas jefferson and others were purchasing wines from the district’s most famous property Ch d’yquem that were evidently sweet; and harvesting details from the 1660s suggest, but do not prove, that the wines made then were probably sweet. Sauternes is the product of a specific mesoclimate. The communes of Sauternes, Barsac, Preignac, Bommes, and Fargues are close to two rivers, the broad garonne and its small tributary, the Ciron. When, in autumn, the cool spring-fed Ciron waters flow into the warmer tidal Garonne, evening mists envelop the vineyards until late morning the following day, when the sun, if it shines, burns the mist away. This moist atmosphere encourages Botrytis cinerea, a fungus that attacks the grapes and causes them to shrivel and rot (see botrytis bunch rot). Mist activates the botrytis spores in the vineyards, and the alternating sunshine completes the process of desiccation. The onset of botrytis is crucial to the evolution of the grapes. Without it, they may indeed ripen sufficiently to ensure that a sweet wine can be made, if fermentation ceases before all the sugar has been converted into alcohol, but the result will lack complexity. As outlined in more detail in noble rot, the overall effect of a benevolent botrytis infection is to increase the concentrations of sugar in grapes and, to a lesser extent, that of tartaric acid; to stimulate the production of glycerol; and to alter considerably the aroma and flavour of the finished wine. The essential difference between mediocre and great Sauternes hangs on the willingness of estate owners to risk waiting until botrytis arrives. There are years when botrytis either fails to develop at all or arrives very late in the year. Proprietors must then decide whether to delay or to begin the harvest. Delay is a risky strategy: the chances of frost or rain, both of which can wreck the harvest, clearly increase as the autumn months wear on, but by picking too early the estate can end up with insipid sweet white wine while its more scrupulous neighbours are in a position to market great botrytized wine. This introduces an economic issue unique to this region. Sauternes is exceptionally costly to make. There are a number of vintages each decade in which it is either impossible to make good sweet wine (and some grapes may be salvaged to make a dry white that qualifies only as a bordeaux aoc) or in which, as in 1991 for example, it can be produced only in minute quantities. Even in excellent vintages, maximum yields are restricted to 25 hl/ha (1.4 tons/acre), a quantity infrequently attained. At Yquem, the average yield is a trifling 9 hl/ha, and at most conscientious estates the yields probably fluctuate between 12 and 20 hl/ha—although total production of the appellation, perhaps tellingly, does not vary nearly as much. (In the red wine districts of médoc or st-émilion, yields of more than 45 hl/ha are routine.) In addition, the harvest is unusually protracted. Botrytis occasionally swoops over entire vineyards, as in 1990 and 2003, but this is rare. More commonly, it performs its unsightly activities patchily. A typical harvesting pattern might be as follows: an attack of botrytis on Sauvignon grapes allows half of them to be picked in late September; two weeks of drizzle follow, during which picking is suspended; finer weather resumes, grapes affected by undesirable grey rot are eliminated, and in late October another attack of botrytis allows the Sémillon and remaining Sauvignon grapes to be picked over a three-week period. The necessity for selective harvesting, or triage, essential for Sauternes, is expensive, as teams of pickers must be kept available for a very long period. More than any other wine, Sauternes is made in the vineyard. Once the grapes have been picked, they are difficult to manipulate. Their must weight (sugar content), their physiological ripeness, and the degree of botrytis infection will all determine quality before the winemaker has got to work. None the less, Sauternes calls for careful vinification. Pressing should be as gentle as possible, and some leading estates still use old-fashioned hydraulic or basket presses for this purpose. Fermentation takes place in tanks or, more usually since the mid 1980s, in barriques, of which 30 to 100% are likely to be new (see barrel fermentation). Fermentation either stops of its own accord when the wine has achieved a balance of about 14% alcohol and a residual sugar level that is the equivalent of a further 4–7% alcohol, or it is arrested with the addition of sulfur dioxide. For more details, see botrytized winemaking. In weaker vintages, chaptalization may be permitted, although better estates avoid the practice, which merely adds sweetness rather than complexity and is often used to disguise lazy harvesting. The wine is usually aged in oak barrels for between 18 and 36 months (see barrel maturation). Less distinguished lots of wine are usually sold off to négociants; in 1978, Yquem bottled only 15% of the crop under its own label, and in 1987, many estates marketed no wine at all. This is all the more remarkable because, despite having very much higher production costs, the Sauternais are not generally rewarded with much higher selling prices than the equivalent red bordeaux made in much greater quantity. Blame fashion. Although the prevalence of botrytis and overall geographical location are common to all Sauternes, specific mesoclimates and soil structures affect the styles of the different estates. barsac is the most distinctive commune, and is entitled to its own appellation, although it can also be sold as Sauternes. Its proximity to the Ciron and its alluvial soil give wines that are often lighter and more elegant than its neighbours. The communes of Bommes and Sauternes itself tend to give the fattest wines, although exceptions are numerous. There are also differences in maturation dates: the grapes at Ch Filhot, for instance, often ripen a week later than those of Barsac. The trend this century has increasingly been to seek harmony in the wines rather than maximum sweetness. All these factors were taken into account when in 1855 the existing estates were classified. Successful candidates were ranked as either first or second growths, with Yquem rightfully given its own super-status (see classification). In the 1960s especially, standards slumped. Producers were especially impoverished and there was a string of poor vintages. Only the richest estates could afford to maintain standards. Elsewhere, corners were cut, grapes were picked too early, and barriques were replaced with tanks. For two decades many classified growths produced wines that were mediocre at best, even in fine vintages. Only with the excellent 1983 vintage did matters improve. Prices rose, and wise proprietors invested in long overdue improvements, which bore fruit in the superb 1986, 1988, 1989, and 1990 vintages and, more recently, the 1996, 1997, 2001, 2003, 2007, 2009, and 2011. The official 1855 classification is once again a reasonably reliable guide to quality, although a number of unclassified growths, such as Ch de Fargues (owned by Comte Alexandre de Lur-Saluces who used to manage Yquem), Gilette, and Raymond-Lafon, are often of first growth quality, and price. After a bad patch, Sauternes is again showing the quality of which it is capable. It combines power, voluptuousness, and elegance, and good bottles can evolve and improve for up to 50 years (longer in the case of Yquem). Given the risks and costs involved in its production, it remains underpriced in relation to the enormous pleasure it brings to those growing numbers of wine lovers who find a fine Sauternes has an undeniable place on the dinner table.