Prosecco, Lambrusco, Sekt, and Asti
The long ageing, autolytic character, and expense associated with the traditional method is not best suited to all grape varieties. The other main method of making sparkling wine is the tank method, also known as cuve close or Charmat. Sugar and yeast are added to the base wine in a large pressurized tank, which may be fitted with rousing paddles to increase yeast contact. Once the second fermentation has taken place, the wine is cooled, clarified by centrifugation and filtration, and given a dosage. The method is cheap and consistent and has the notable advantage of preserving freshness and varietal character. On the other hand, it calls upon a large upfront investment, requires a skilled operator to prevent any loss of pressure, and lacks the charm and cachet of the traditional method. It is also unsuited to small-scale production.
Prosecco, most lambrusco, and most Sekt, amongst others, are made using the tank method. Prosecco is made in the area of Treviso in northeast Italy, where the cool and continental climate is perfectly suited to the late-ripening prosecco (Glera) grape. The DOCG delimited area covers 4,100 hectares running into the pre-Alps and Dolomites in the north. Most prosecco is made in the Conegliano and Valdobbiadene area. Prosecco from the hill of Cartizze, a vineyard of 107 hectares, is particularly rich and creamy and highly rated. The bulk of the prosecco production (around 20 million bottles) is spumante, most of the rest is frizzante (lightly sparkling), and a small amount is still. Prosecco should be drunk young. It is light, fresh, and intensely aromatic with primary fruit flavours, a modest alcohol of around 11%, and a signature slightly bitter finish. The traditional style is off dry with a sugar content of 16-17g/l that nicely fills out the wine. Today, much of exported prosecco is brut in style so as to suit modern tastes and best compete with champagne.
Lambrusco is, in the main, a red frizzante wine that is made from the eponymous lambrusco grape, a black grape that encompasses several varietals and that has been in cultivation since Roman and even Etruscan times. For a period in the 1970s and 1980s, it was the biggest selling import wine in the United States. The grapes and the wine originate from four areas of Emilia-Romagna and one area of Lombardy. The climate is Mediterranean and the soils are fertile, and yields can be fairly high. Most lambrusco is made by the tank method in co-operatives, and is of rather ordinary quality. Of the five Lambrusco DOCs, Lambrusco di Sorbara is the most highly regarded, with the best examples being made by the traditional method. Lambrusco is characterized by a flavour of sour cherries, high acidity, and a dry or off-dry style.
About 90% of Germany’s Sekt is made from inexpensive base wine sourced from outside Germany — mainly Italy, France, and Spain. The remainder is Deutscher Sekt, that is, Sekt made from German grapes. The vast majority of Sekt and Deutscher Sekt is made by the tank method and sold under the label of a large and inexpensive brand. The small amount of Deutscher Sekt that is made by the traditional method tends to consist of riesling, chardonnay, or the pinot varieties. The very best are likely to state the vineyard name and the vintage on the label. Sekt is big business in Germany, so much so that three of the world’s five biggest producers of sparkling wine are German.
Asti (formerly asti spumante, a name that had acquired a noxious reputation) is made from moscato bianco, that is, muscat blanc à petits grains, from a delimited region in southeast Piedmont, Italy. The DOCG limited areas are centred on the towns of Asti and Alba. Here the climate is continental and the land calcareous and gently sloping. The grapes are harvested by a large number of growers and sold off to négociants. The method of vinfication is the Asti method or single tank fermentation method. The must is transferred into large tanks and chilled to almost 0°C to inhibit fermentation. The tanks are sealed and pressurized and the temperature is raised to 16-18°C for a single fermentation to 7-7.5% alcohol and a pressure of around 5 atmospheres. The wine is then cooled to 0°C to halt fermentation and membrane filtered to remove the yeast and yeast nutrients. Finally, it is bottled under pressure using cool sterile bottling. Asti can also be made by double fermentation, with a second fermentation from 6% to 7.5% taking place in a sealed tank to build up pressure. The wine is fresh and intensely fruity and floral with dominant aromas of peach and musk and enough acidity to balance out the 3-5% residual sugar. Asti should not be confused with Moscato d’Asti, which is made from the same grape in the same region, but which is frizzante and with even lower alcohol. The Asti DOCG has the largest production of all Italian appellations, with an annual output of almost 90 millions bottles.