How Prosecco Superiore is made.
Valdobbiadene Prosecco Superiore DOCG is a sparkling wine made with the Martinotti method, also called Charmat: the base wine, still, ferments a second time inside an autoclave, a large sealed steel tank that holds the pressure. That’s where the bubbles are born. It usually stays there from one to three months.
Valdobbiadene, explained · 5 November 2026 · 4 minutesFirst there’s a still wine.
It all starts with Glera, the white grape of the hills between Conegliano and Valdobbiadene: at least 85%, the rest can come from local varieties such as Verdiso, Bianchetta and Perera. On the steep hills the harvest is by hand, between late August and September; in the Rive and in Cartizze it’s compulsory. The grapes are pressed gently, the must ferments once and becomes a light, still white wine with the right acidity. That’s the base wine. No bubbles, not yet.
Then the autoclave.
The autoclave is a sealed steel tank that holds pressure and keeps the temperature under control. The base wine goes in with a little sugar and selected yeasts. The yeasts eat the sugar and make alcohol and carbon dioxide: but the tank is sealed, so the gas can’t escape and stays in the wine. Those are the bubbles. This stage is called presa di spuma, the taking of the foam, and the pressure rises to at least three bar, as the law requires for a sparkling wine.
How long it takes.
The Conegliano Valdobbiadene DOCG rules set no minimum for the second fermentation of the spumante: they set one for the «sui lieviti» version, ninety days, and for the Rive, which go on sale from the first of March after the harvest. In practice the wine stays in the autoclave from one to three months: the longer, the finer the bubble and the more relaxed the wine.
Why not in the bottle.
Champagne and Franciacorta do their second fermentation in the bottle, on the lees, for months or years: that’s the classic method, and it brings notes of bread crust and yeast. Glera is a fragrant grape, flowers and fresh fruit: the Martinotti method, shorter and in steel, keeps those aromas intact. It’s not a better or worse method. It’s the right method for this wine.
Brut or Extra Dry: what changes.
What changes is the residual sugar, how much is left at the end. By law a Brut has up to 12 grams per litre; an Extra Dry between 12 and 17; a Dry between 17 and 32. SERALBA Brut has 6.6 grams per litre: dry, taut, for dinner and for the night. SERALBA Extra Dry has 16.5: softer, for the aperitivo, while the sun is still up. Both 11.5% vol.
The two bottlesThree quick questions.
Is Prosecco a champagne?
No. Champagne is French, comes from other grapes and does its second fermentation in the bottle. Prosecco Superiore comes from Glera, on the hills of Conegliano and Valdobbiadene, with the Martinotti method in an autoclave. Two different wines, not two versions of the same one.
What is the presa di spuma?
It’s the moment the wine takes its bubbles: the second fermentation in the autoclave, with sugar and yeasts, in a sealed tank that keeps the carbon dioxide in.
Is Prosecco Superiore always sparkling?
Almost always. The rules also allow a frizzante, lightly sparkling, and a still version, but the spumante is the one you find almost everywhere, and the one SERALBA makes.
- Consorzio di Tutela del Conegliano Valdobbiadene Prosecco DOCG · prosecco.it
- Production rules of the Conegliano Valdobbiadene Prosecco DOCG (art. 2, 4, 5 and 7) · valoritalia.it