Pét-Nat and Rifermentato – what is the difference?

Frizzante, Perlwein, and Pét-Nat can be produced in different ways.

The industrial approach is usually based on the Martinotti method (also known as the Charmat method), a pressurized tank fermentation process. While this method is used for the majority of Frizzante-style wines, it is not our focus here.

The second—and for us more relevant—approach is based on bottle fermentation, where it is important to distinguish between two fundamentally different methods: Pét-Nats, which are particularly popular in Austria and France, and Rifermentati, which are especially popular among natural wine producers in Italy.

Pét-Nat or Méthode Ancestrale

Pét-Nats are sparkling wines produced through a single fermentation process. Fermentation begins in a tank (usually stainless steel), and when the wine still contains around 12–15 grams of residual sugar, it is bottled under crown cap. Fermentation then finishes in the bottle, producing both alcohol and carbon dioxide. The amount of residual sugar determines the desired final pressure in the bottle. As a rule of thumb, approximately 4 grams of residual sugar generate 1 bar of pressure.

Pét-Nats typically develop a substantial sediment of dead yeast cells and other microorganisms. Over time, these can influence the sensory profile of the fully fermented sparkling wine—sometimes positively, sometimes negatively. For this reason, most winemakers disgorge their Pét-Nats.

Historically, the Méthode Ancestrale was also used in Italy’s traditional sparkling wine regions, particularly in the Lambrusco area. Today, however, it has become relatively rare there. Instead, producers generally rely on a second fermentation in the bottle, usually without disgorgement (sboccatura in Italian).

In our portfolio, Pét-Nats are produced by Vitikultur Moser, Georg Schmelzer, Koppitsch, Aldo Viola, and Raica.

Rifermentato

The production of Rifermentato resembles the traditional method (Méthode Champenoise). In the production of Spumante (for example at Cá del Vent), the traditional method is essentially followed step by step. With Frizzante, however, some important differences emerge.

In general, both Rifermentato and the traditional method involve two fermentations. After the first fermentation, the fully fermented wine is aged for a period—typically a few months—in wood, stainless steel, or cement vessels. During this time, unwanted suspended particles are allowed to settle.

Unlike Champagne, however, the second fermentation in the bottle for artisanal Italian Frizzante (such as Lambrusco and similar wines) is not initiated with sucrose, but rather with a grape-derived product. In Italy, the addition of beet sugar to wines with less than three bars of pressure is prohibited. Producers therefore use either sweet grape must or grape sugar.

As with Pét-Nat, fermentation then continues in the bottle. However, the sediment consists primarily of dead yeast cells, which, given sufficient aging time, contribute highly desirable autolytic aromas—such as brioche, bread crust, and nuts—to the wine. The yeast also acts as a natural antioxidant, protecting the wine from oxidation.

For this reason, artisanal Rifermentato Frizzante is rarely disgorged, if at all, and generally ages exceptionally well.

In our portfolio, Rifermentati are produced by Podere Sottoilnoce, Ca’ de Noci, Bergianti, Davide Spillare, Nevio Scala, and Pranzegg.