Santa Margherita

Sparkling wines can be produced by two different methods: the classic method (which until recently was referred to – even in Italy - as the Champagne method), which involves a second fermentation in the bottle and the Charmat or Martinotti method where the second fermentation takes place in a pressurized tank.
For both methods the first stage is to obtain a base wine, following traditional vinification procedures for making white wine. Various grapes may be used for the production of sparkling wines: either those with white berries (such as Chardonnay, Pinot Bianco, Riesling, Moscato and Prosecco) or dark-skinned grapes (such as Pinot Noir). The grapes to be used for sparkling wines are usually harvested just before they are completely ripe so they have the most fragrant aromas possible and good acidity which will give the wine freshness and longevity.
In the classic method the base wine is bottled and undergoes a second fermentation in the bottle. To start this, the “liqueur de tirage” is added: this is a syrup made up of selected yeasts, cane sugar (up to 24g/bottle, given that 4 grams provide around 1 atmosphere of pressure) and mineral salts.
Once they have been filled, the bottles are closed with a special stopper, a cylinder (the so-called “bidule”, or cartridge) placed with the opening facing down towards the wine, over which the better-known crown cork is applied. The bottles are then arranged horizontally in racks for the so-called “prise de mousse”, which results from the second fermentation in bottle.
After around 40 days the “prise de mousse” is complete which means that the right pressure (normally 5-6 atmospheres) has been reached: the sparkling wine will have become dry again and will have a higher alcoholic strength. At the end of this period the bottles are moved to special wooden trestles in the shape of a capital A, with holes to hold the bottles. These structures are known as “pupitres” and are used to bring the bottles from an initially horizontal position to a vertical one, head down. By means of the operation called “remuage” (riddling), which is carried out by hand, the lees (yeasts) that have amassed along the inside of the bottle are gradually moved towards the “bidule”; the whole of this process takes place very slowly over the course of several months.
The next stage is that of disgorgement (“dégorgement”): the neck of the bottle is immersed in a liquid solution cooled to -25° C. After a short time the part of the wine immersed in the solution freezes and forms a cylinder of ice, containing all of the deposit that has formed whilst the wine has been maturing on its lees. The bottle is then uncorked mechanically and the little cylinder is expelled.
Now the bottle has to be filled up to replace the liquid which has been lost. This is done either with some of the base wine kept for the purpose or by adding the so-called “liqueur d'expédition”, a sugary syrup, the exact composition of which is each producer's secret formula. In the former case, when just base wine is added, the sparkling wine is referred to as “pas dosé” or “dosage zéro”; in the latter it is defined as “extra-brut” or “brut”, depending on the amount of sugar in the syrup used for topping-up.
Now the proper champagne cork can be fitted, immediately covered with its little metal cage, or “muzzle”. This process is known as “habillage”.

Charmat o Martinotti?
With the Charmat or Martinotti method (there is some argument about exactly who invented this method, which appears to have been invented by the Italian Martinotti and then perfected – and registered - by the Frenchman Charmat) the base wine, with added sugar and selected yeasts, is placed in stainless steel pressurized tanks which are hermetically sealed and can resist high pressures. After around 10-15 days the “prise de mousse” has taken place, so the activity of the yeasts has to be stopped. This is done by bringing the wine temperature from +14° C to -4° C. This causes the yeasts to die and fall to the bottom. The sparkling wine is left for a period of between 1 and 6-9 months (the “extended” Charmat method) on the lees and then filtered, cleaned and transferred to a second (“hyperbaric”) tank from where it is bottled. Corking and muzzling take place immediately afterwards.