The Charmat Method (or Martinotti Method) is a sparkling wine production technique which differs from that used in the Classic Method (or Champenoise Method).
The main difference is that the second fermentation process (i.e. what determines the acquisition of the product’s effervescence and the development of the CO2 dissolved within the product itself) in the Charmat Method takes place inside airtight containers called autoclaves. As regards the Classic Method there is a second fermentation in the bottle.
The Charmat Method is a production process of sparkling wines that was born in 1985 from an idea of Federico Martinotti, director of the Experimental Institute for Enology of Asti. However, in 1910 Eugene Charmat patented the sparkling method developed by Martinotti.
In order to produce a Charmat Method sparkling wine you can start from a cuvée of basic wines. After the normal fermentation process, these wines undergo a second fermentation in which you have to add yeasts and sugars.
During this phase the yeasts consume the sugars and transform them into alcohol and carbon dioxide, giving rise to the characteristic bubbles.
When the period in which the wine rests on the yeasts drags on beyond 9 months, we speak of Long Charmat Method.
The phases of the Charmat method
Most of the phases of the sparkling wine production with the Charmat method take place in isobaric conditions, in order not to disperse the carbon dioxide developed during the fermentation processes. The detailed sequence for producing a Charmat method sparkling wine is the following:
- Blend of basic wines;
- Addition of sugars and selected yeasts;
- Second fermentation
- Transfer and filtration under isobaric conditions
- Isobaric bottling
Classic or Charmat method
The Charmat method has had great success due to its speed but also because the production in an autoclave has proved to be particularly suitable for the more aromatic vines.
On the other hand, the Classic Method sparkling wine is generated by a more complex and longer second fermentation process, which often leads to an evolution of the varietal aromatic profile.
The Charmat Method therefore has the advantage of being faster, more efficient and of favoring the freshness and any varietal notes of the product. We can thus obtain more versatile sparkling wines.
Charmat Method of Rocca dei Forti
All the Rocca dei Forti sparkling wines are produced with the Charmat Method and are the result of a very rigid internal process, to guarantee a qualitative final result.
The process is carried out through strict compliance checks on:
- Fermentation temperatures;
- the choice of yeasts for each product;
- the period of aging in autoclave.
As regards the fermentation, the lower the temperatures, the more elegant the response in terms of aromas.
Temperatures go from a minimum of 16 degrees to a maximum of 22 degrees. The lower the temperature, the longer the fermentation and the more the final product has better olfactory and gustatory qualities.
The choice of yeasts
The choice to use selected and specific yeasts for each variety, on the other hand, allows each variety to express itself at its best in terms of aromas and final result.
The period of aging
The period of aging in autoclave also affects the final quality of the product.
The rest on the lees allows the release of some compounds in the product that make it more complex from a gustatory and olfactory point of view, making it more structured and softer.
Furthermore, all the autoclaves present into the Rocca dei Forti buildings are equipped with a stirrer that “stirs” the mass and resuspends the fine lees for an even greater qualitative, olfactory and gustatory enrichment (bâtonnage).