Asti is the name of a province, a town and a wine – all to be found in Piedmont, north-western Italy. The suffix d'Asti appears in the names of several wines from the Asti area, including Barbera d'Asti, Dolcetto d'Asti and of course the famous Moscato d'Asti. When used alone (just 'Asti') on a wine label, it indicates the wine formerly known as Asti Spumante – a refreshing, slightly sweet, sparkling white wine made from Moscato Bianco grapes.
In late 1993, Asti Spumante was promoted to the top-level DOCG classification, at which point the 'spumante' was officially dropped, reducing its name to simply Asti. The latter step was taken in order to lift the wine above the many other Italian wines which bear the suffix spumante or frizzante. Almost invariably, these other wines are simply the sparkling version of their appellation's main style. In Asti, however, sparkling is the key style, so the wine had no need to be qualified (and perhaps cheapened) by the adjective spumante.
Each of the various d'Asti wine styles has its own defined viticultural zone (these all overlap to some extent). The viticultural zone for Asti wine (without the 'd') covers an area in the hills just south of Asti town. It takes in about 50 communes of the Cuneo, Asti and Alessandria provinces, and measures roughly 30 miles (50km) from east to west. It stretches from Serralunga d'Alba (home to many top-end Barolo wines) in the west to Acqui Terme in the east. This production zone is identical to that of Asti's sweeter, lower-alcohol cousin, Moscato d'Asti, with which it is often confused.
There are several subtle differences between Asti and Moscato d'Asti. Asti is off-dry, fully sparkling and has an alcohol content closer to 9% ABV. Moscato d'Asti is semi-sweet, very gently sparkling and has an alcohol content around 5% or 6% ABV. Strength of sparkle is key here, and is perhaps the easiest way to distinguish between the two wines. In Italian sparkling wine speak, Asti is spumante (4 atmospheres of pressure) while Moscato d'Asti is frizzante (1 atmosphere of pressure). Asti is packaged with thick, sturdy bottles and a wired-down cork (as per Champagne), while Moscato d’Asti's relatively low pressure requires only a standard bottle and cork.
Almost all Asti is produced end-to-end in large, stainless-steel tanks, using what has become known as the 'Asti Method' (an extension of the Charmat Method). As soon as the Muscat grapes have been picked and brought to the winery, they are de-stemmed and pressed. The resulting must is filtered and kept chilled until required; almost unique in the wine world, Asti wine can be made 'on demand' from existing stocks of must. The must is converted into wine by fermenting it in a pressurized tank. As yeasts convert the grape sugars to alcohol, carbon dioxide gas is produced as a by-product. This gas is remains 'trapped' in the wine, creating its all-important sparkle. When the alcohol level reaches around 8% or 9%, the wine is chilled and sterile filtered, removing the yeasts and thus stopping the fermentation.
Because Moscato d'Asti is designed to be sweet, light, delicate and floral, it typically takes the lion's share of the finest, ripest grapes. This leaves the more acidic, greener grapes for the Asti wines. The theory is that the stronger sparkle and higher alcohol will compensate for the under-ripe flavors; after all, the world's most famous sparkling style, Champagne, essentially requires a slight under-ripeness in the grapes. In reality, however, the wine's residual sugar seems even more obvious because it isn't balanced out with the kind of lifted, floral, grapey flavors that make Moscato d'Asti so alluring. This has led Asti's reputation to fall behind that of it's more-famous cousin, and yet Asti has made a name for itself as an easy-drinking, sparkling wine typically accessible at an affordable price.
The Asti wine market is dominated by about 15 of Piedmont's larger wineries, all of which produce a wide range of wines under various Piedmont appellations. Roughly eight in every ten bottles of Asti is made by these 15 producers, and six of those eight are exported. There is a growing trend, however, for smaller estates to produce their own higher-quality Asti wines from estate-grown grapes. As Italy's sparkling wine production continues to gain traction, and the category continues to boom on a global scale, these more artisanal Asti wines may prove vital in maintaining the appellation's reputation.