Charmat Method

The Charmat Method has a split heritage rooted in both Italy and France. Federico Martinotti, director of the Experimental Institute for Enology in Asti, invented and patented the concept of secondary fermentation in large pressurized tanks in 1895. French inventor Eugène Charmat subsequently improved and re-patented the process in 1907, designing the specialized pressurized stainless steel tanks that became the industry standard. Because both men contributed meaningfully, the method is known by both names depending on country and context.

• Federico Martinotti (1860-1924), director of the Experimental Institute for Enology in Asti, filed the original patent in 1895
• Eugène Charmat patented his improved pressurized tank design in France in 1907, lending his name to the method internationally
• Also known as cuve close (French), metodo Italiano, or simply the tank method
• The method is called Metodo Martinotti in Italy, where Martinotti's original contribution is more widely credited

The Charmat Method begins with a still base wine that is transferred into a large, sealed stainless steel autoclave along with added yeast and sugar to trigger secondary fermentation. Carbon dioxide produced during fermentation is captured under pressure within the tank. Fermentation is conducted at cool, controlled temperatures to preserve delicate aromatics. Once the desired pressure is reached, the wine is racked, chilled, filtered under isobaric conditions to avoid CO2 loss, and bottled under pressure.

• Secondary fermentation takes place in temperature-controlled autoclaves at approximately 15 to 18 degrees Celsius to preserve grape aromatics
• Yeast and sugar are added to the sealed tank; CO2 produced has nowhere to escape and dissolves into the wine
• All post-fermentation stages, including racking, filtration, and bottling, occur under isobaric conditions to retain carbonation
• Prosecco DOC requires a minimum of 30 days of secondary fermentation; the Long Charmat style extends tank time to up to nine months

The Charmat Method is the dominant production technique for Prosecco, Italy's most exported sparkling wine, with production approaching 600 million bottles in 2018. It is also widely used for Lambrusco and Asti Spumante in Italy, much German Sekt, and sparkling wines in the United States, Brazil, and beyond. By contrast, Champagne and Cava require secondary fermentation in the bottle under their respective appellation rules, as does Franciacorta DOCG in Italy.

• Prosecco DOC and DOCG wines are overwhelmingly produced using the Charmat-Martinotti method, with bottle fermentation also permitted but rarely used
• German Sekt is frequently produced using the Charmat method, including well-known brands such as Henkell Trocken
• Cava (Spain) and Champagne (France) legally require bottle fermentation using the traditional method
• The method is also common for sparkling wines made from aromatic varieties in the United States, Brazil, and Argentina

Because Charmat Method wines spend little or no time aging on lees, they retain the bright primary aromas of the grape itself rather than developing the bready, autolytic notes associated with long bottle aging. This makes the method especially suited to aromatic varieties like Glera, Moscato, and Riesling. Bubbles in Charmat wines are typically softer and dissipate more quickly than those in traditional method wines, as tank pressure sits at 2 to 4 atmospheres versus 5 to 7 atmospheres for bottle-fermented wines.

• Fresh primary aromas dominate: green apple, pear, white peach, citrus zest, and delicate floral notes are typical
• Minimal yeast autolysis character means little to no bready, brioche, or toasty notes
• Softer carbonation at 2 to 4 atmospheres gives a lighter, more approachable mouthfeel than traditional method wines
• Wines are designed for early consumption to capture their fresh, vibrant fruit character at its peak

The fundamental difference between the two methods lies in where secondary fermentation takes place. In the traditional method, each individual bottle undergoes its own secondary fermentation followed by extended aging on yeast lees, developing complex autolytic flavors of bread, brioche, and nuts. The Charmat Method conducts secondary fermentation in a single large pressurized tank, prioritizing fruit preservation and production efficiency over secondary complexity. Neither method is inherently superior; each suits different grape varieties, flavor goals, and price points.

• Charmat: secondary fermentation in a large tank with minimal lees contact; traditional method: fermentation in individual bottles with extended lees aging
• Traditional method develops toasty, bready autolytic complexity; Charmat preserves fresh primary fruit and floral aromas
• Charmat wines carry softer carbonation at 2 to 4 atmospheres; traditional method wines reach 5 to 7 atmospheres with finer, more persistent bubbles
• Charmat production is faster and less labor-intensive, enabling more accessible price points without sacrificing aromatic quality