All of sparkling wine is made by provoking a second fermentation of the wine in a pressurized environment.
Sparkling wine gets its fizziness from CO2, a natural by-product of fermentation. When fermentation takes place in an unpressurized environment, that CO2 escapes and the resulting wine is still (in other words, not sparkling). When fermentation takes place in a pressurized environment, the CO2 is captured.
There are two main methods to makes sparkling wine: there’s Tank Method, which is definitely more complicated than carbonation. And then there’s Classic Method, which is, well, insanely hard.
The two methods have differs each other on almost all the aspects.
Terminology: These two methods of making a sparkling wine have many aliases.
- Classic Method – aka Traditional Method, Champagne Method, Méthode Traditionnelle, Méthode Champenoise, and Méthode Classique. The classic method calls for the wines to undergo their second fermentation in bottle, a process perfected by winemakers in Champagne where it is called the méthode champenoise or Champagne method. Because European Union regulations prohibit anyone outside of the Champagne region from using the term, European winemakers use the term classic method or traditional method. In Italy it is called Metodo Classico, that's why italian sparkling wine obtained with the classic method are called Spumante Metodo Classico. This is the method used to produce all the sparkling wine available on Priwine by Letrari (Cuvée Blanche, Dosaggio Zero Riserva, Brut Rosé and Riserva del Fondatore) and Rainoldi (Brut Rosè and Cuvée Maria Vittoria).
- Tanks Method – aka Bulk Method, Charmat Method, Cuve Close, Martinotti Method or Metodo Italiano. This is the method used to produce the Bollicine di Prosecco by Serafini & Vidotto available on Priwine.
Base Wine and Liqueur de Tirage: Both Traditional and Charmat methods begin with the creation of a base wine. This base wine is many times a blend of wines, from different grape varieties, different vineyards, and/or different vintages. Next, yeast and sugar are added to a small amount of the base wine. This mixture, called the liqueur de tirage, is added back to the base wine. It’s time for secondary fermentation! The base for Cuvée Blanche by Letrari is chardonnay while different mix of chardonnay and pinot noir are used for Brut Rosé,Dosaggio Zero Riserva and Riserva del Fondatore by Letrari. Rainoldi sparkling wines (Brut Rosé and Cuvée Maria Vittoria) are based mostly on Nebbiolo with a small percentage of autochthonous varieties (Pignola, Rossola). Glera is the variety used for Bollicine di Prosecco by Serafini & Vidotto.
Secondary Fermentation: The yeast converts the sugar in the wine to CO2 and alcohol. The CO2 is trapped in either a bottle or a tank, depending on the method.
- Classic Method – The base wine is put into bottles to undergo the secondary fermentation. The bottles are aged from 9 months to over 5 years. Letrari Brut Rosé takes at least 24 months, Dosaggio Zero Riserva at least 48 months and Riserva del Fondatore stays on the lees for minimum 92 months. It's quit a long time, but you know, is the founder.... Rainoldi Brut Rosé takes at least 36 months and Rainoldi Cuvée Maria Vittoria lies on the lees for not less than 60 months.
- Charmat Method – The wine is put into a stainless steel pressure tank to undergo the secondary fermentation. The process typically takes one to six weeks, a much shorter time than the Traditional Method. Bollicine di Prosecco by Serafini & Vidotto takes six weeks.
Riddling/Removal of Lees
- Classic Method – Every bottle of traditional method bubbly undergoes the riddling process. This is when the bottles are put into riddling racks and rotated on a specific schedule to move the lees (dead yeast) to the neck of the bottle.
- Charmat Method – No riddling needed for this sparkling wine. Instead, the bulk wine is filtered prior to bottling to remove the lees.
- Classic Method – Yes, with this method, disgorging is needed. Disgorging is a process where the riddled wine is placed in a neck freezer, which freezes all the lees into a nice little ice plug. Using a disgorging machine (or manually!!), the cap is removed from the bubbly and the ice plug is quickly removed.
- Charmat Method – Nope. Since the yeast was removed via filtering, you get to skip this step with the charmat method.
Dosage: This is where the winemakers put their final stamp on the wines. They create a liquor made of still wines and sugar to add to the wine. This is known as the dosage; the amount of sugar used for the dosage varies and will dictate the sweetness of the wine.
- Classic Method – A dosage is added to each bottle to not only enhance the wine, but also to replace the wine that was lost in the disgorging process.
- Charmat Method – These wines also receive a dosage, but it is added to the bulk wine prior to bottling.
Adding sugar is the means to create the different categories of sparking wine, which are classified as defined by EU regulations, in ascending order of sweetness as follows:
- Brut Nature, Nature, Pas Dosé or Dosaggio Zero: less than 3 grams of sugar per litre. Priwine catalogue includes Dosaggio Zero Riserva by Letrari and Cuvée Maria Vittoria by Rainoldi
- Extra-Brut: 0-6 grams of sugar per litre
- Brut: less than 12 grams of sugar per litre. Priwine offers to Swiss wine lovers the Cuvée Blanche, Brut Rosé and Riserva del Fondatore by Letrari or Brut Rosé by Rainoldi
- Extra-Dry: 12-17 grams of sugar per litre. That's the case for Bollicine di Prosecco by Serafini & Vidotto
- Sec: 17-32 grams of sugar per litre
- Demi-Sec: 32-50 grams of sugar per litre
- Doux: more than 50 grams of sugar per litre
- Classic Method – With this method, the wine is bottled prior to secondary fermentation and remains in this bottle throughout production. Each bottle is unique and has its own batch. On the back of each label, you usually find the batch number, bottle number, and disgorgement date.
- Charmat Method – These wines are not bottled until the very end of production.
Taste, Aroma, and Bubbles
- Classic Method – Because these wines have more contact with the lees than the charmat method wines, traditional method bubbly typically has aromas and flavors such as toastiness, nuttiness, caramel, and yeastiness. The texture seems more smooth and creamy. The bubbles are tinier, and usually feel less aggressive in your mouth than the bubbles of charmat wines.
- Charmat Method – These sparklers tend to be fruitier than traditional-method sparkling wines, especially those wines that are fermented for a shorter time period. The bubbles are typically larger and coarser than the bubbles in traditional method wines.