Asti method

Single fermentation of Moscato must in autoclave

In the Asti method, grape must ferments only once, in a closed pressure tank, and the fermentation is stopped before all the sugar is used, so the wine keeps sweetness and relatively low alcohol.1 The Asti rules require at least 1 month for the process, the same as the EU minimum for quality aromatic sparkling wine.1,2

The steps

  1. White aromatic grapes are picked: Asti vineyards must be at least 97% Moscato bianco, with up to 3% other white aromatic varieties.1
  2. The grapes are pressed.
  3. The must goes straight into a closed pressure tank (autoclave). There is no still base wine and no liqueur de tirage.1
  4. A single natural fermentation runs in the autoclave; its CO2 stays dissolved.1
  5. The fermentation is stopped while sugar remains, which leaves the wine sweet and lower in alcohol.1
  6. The wine is bottled. The rules count bottle refinement within the 1-month minimum.1

How the CO2 is produced and kept

All the gas comes from one fermentation of fresh must. Because the tank is closed from the start, the CO2 from that fermentation is captured rather than released, as happens in an open vat when still wine is made. Stopping the fermentation early fixes both the sweetness and the alcohol: Asti needs a total alcoholic strength of at least 11.5% vol, of which at least 6% vol actual.1 The rest of the total is the potential alcohol of the remaining sugar.

The method differs from the tank method, where a finished dry base wine re-ferments, and from the ancestral method, where a single fermentation is finished in the bottle.

Legal minimums

WineRule
Asti spumanteProcess at least 1 month, including bottle refinement1
Asti metodo classicoAt least 9 months on lees in the same company1
Moscato d'AstiPressure not above 2.5 bar, CO2 only from fermentation, actual alcohol 4.5-6.5% vol, total at least 11% vol1
EU quality aromatic sparkling wineProcess at least 1 month2

In the EU, quality aromatic sparkling wine is a quality sparkling wine made only from grape must or must in fermentation from specific varieties. It needs at least 3 bar, at least 6% vol actual alcohol and at least 10% vol total.3 Moscato d'Asti, at no more than 2.5 bar, falls in the semi-sparkling pressure range rather than the sparkling one. See EU categories of sparkling wine.

Note: the EU 1-month figure was read in the legislation.gov.uk reproduction of Regulation (EU) 2019/934, Annex II, which a 2021 amendment changed in part; it should be re-checked against EUR-Lex.2

Appellations and label wording

The Asti DOCG rules cover Asti spumante made in autoclave, Asti metodo classico made by second fermentation in bottle, and Moscato d'Asti.1 For sweetness terms on the label see label terms in EU law and sweet sparkling wine.

See also

AstiRegionsTank methodMethodsAncestral methodMethodsEU categories of sparkling wineMethodsMuscat Blanc à Petits GrainsGrapesSweet sparkling: demi-sec and douxStyles

Sources

  1. Regione Piemonte. Disciplinare di produzione DOCG Asti (2025-01)
  2. legislation.gov.uk (The National Archives). Commission Delegated Regulation (EU) 2019/934, Annex II (sparkling wine oenological practices), as reproduced on legislation.gov.uk (2019-03-12)
  3. legislation.gov.uk (The National Archives). Regulation (EU) No 1308/2013, Annex VII Part II (categories of grapevine products), as reproduced on legislation.gov.uk (2013-12-17)

Facts checked on 2026-10-19