How it is produced
The two most important production methods of a spumante wine are the Classical Method and the Charmat (or Martinotti) method.
Classical MethodThe classical method requires a re-fermentation in bottle with a very long period of refinement with yeasts (up to several years).
Charmat MethodWith the Charmat method refermentation is carried out in fermenters in stainless steel under pressure for a contact period with yeasts that is much shorter.
Ancestral MethodA third method to produce spumante wines, again in bottle, consists in bottling the basis wine with its yeasts and the presence of a sugary residual, which, with rising temperatures in spring will take to re-fermentation and effervescence: it is the so called Ancestral Method.
Spumante wines are wines with an overpressure of at least 3,5 absolute atmospheres within the bottle, obtained through process of re-fermentation. The term ‘spumante’ refers to the foam (spuma) that is produced when uncorked.
Bubbles (‘perlage’ in technical terms) that are formed are assessable on the basis of their number, delicacy and persistence, elements identifying the quality of a spumante wine.
The two most important production methods of a spumante wine are the Classical Method and the Charmat (or Martinotti) Method.
The term Prosecco refers exclusively to spumante wines produced in some areas of Veneto and Friuli Venezia Giulia, using not less than 85% of Glera grapes.
Classical or TraditionalThe Champenoise Method
From a regulatory point of view the term ‘champenoise’ can be used exclusively with reference to Champagne, although classical or traditional Method are synonims of the same production method.
This method is characterised by a second fermentation that, after the first one transforming must into wine, takes place within the bottles. Re-fermentation in bottle is activated by adding yeasts and sugar, and it is followed by a long period of rest on exhausted yeasts.
The Classical MethodClassical or traditional methods are synonyms of champenoise, referring both to the same production method, but from a regulatory point of view the French term can be used only with reference to Champagne.
This method is characterized by a second fermentation which, after the first transforming must into wine, takes place within the bottles. Bottle fermentation is activated by adding yeasts and sugar, and the following stay on yeasts generally lasts from a minimum of 18 months, up to many years.
The origin of spumante wine is located in France, well before the 15th century: the drop in temperatures happened in Europe pushed to study systems of re-fermentation for wines that, because of cold weather, were not any more able, after grape harvest, to correctly complete alcoholic fermentation, which means to transform all sugar into alcohol. It was, then, tried to stimulate a second re-fermentation with the first hot temperatures in spring to give wine a higher alcoholic content, favouring that effervescence that, for long time, was not considered a merit, but that later became the distinguishing mark of spumante wines. Over the years, both at court in London and in Versailles, wine with bubbles started to be appreciated. Legend says that it was the monk Dom Perignon who decisively contributed to create Champagne as we know it today.
In the first phase the producer will take care to carry out the “assemblàge” between the various products and then carry out the “coupàge“: the blending between different base wines in such proportions as to capture the best from each base wine and form the “cuvée“, which will be subjected to a second fermentation.
Here we understand the importance of the role of the winemaker and his sensory capacity. It is not excluded that the base wines of the first fermentation can be obtained from grapes from a single vine, from a single vineyard, from different vines and different vines, from the same vintage (millesimato) or from different vintages.
Once the first fermentation has been made and the base wine is obtained, the wine must be refermented by adding a sweet syrup made up of sugar, yeast and a nitrogenous food for the yeasts. This mixture forms the so-called “liqueur de tirage“. Bottled with a metal crown cap inside which there is a plastic cylinder (the “bidule“) to collect the lees formed by the decomposition of yeasts that have completed their task.
This refermentation is the real second fermentation: the formation of new gas thanks to the work of yeasts that digest sugar and generate carbon dioxide as a by-product of alcoholic fermentation.
The gas – trapped in the bottle – gives rise to the characteristic bubbles of sparkling wines (perlage).
In the following months, the sparkling wine ages through contact with its lees: the release of the compounds of the exhausted yeasts gives the sparkling wine its taste-olfactory complexity.
It is the oenologist who chooses the right moment to separate the sparkling wine from the lees, practicing the “remuage“.
This phase has something fascinating and romantic about it. Once manually and today, for the most part, mechanically, the bottles are brought into an almost inverted position, to facilitate the descent of the deposit of the lees towards the cap and ensure that they are collected inside the “bidule“.
The remuage was carried out, according to tradition, with the help of specific racks (pupitre) that allow you to gradually turn the bottle and progress through different oblique inclinations.
After a few steps the bottles will be placed vertically, but upside down. To allow the elimination of residues deposited in the “bidule” (the plastic cylinder attached to the inside of the crown cap), a further step is required: disgorging (or dégorgement).
Each bottle is uncorked and the internal pressure pushes out the deposit of residues. Today disgorgement is carried out with the “a la glace” system, placing the ends of the bottles at a temperature of -20 degrees, so that the deposit freezes before uncorking the container and expelling it.
In the labels of sparkling wine bottles produced with the classic method, the disgorgement date is generally indicated, essential to be able to understand how many months of aging on the yeasts in the bottle the sparkling wine has carried out.
Liquer d’expedition is a mix for disgorgement that often contains also sugar and wine distillate: every manufacturing house has its secret recipe. The bottle is then closed with the classical mushroom-shaped cork in cork tree and a metal little cage to avoid it gets open. Inside it, there can be pressures up to 6/7 bar.
Spumante wines are classified based on residual sugar, and they can also be not dosed (pas dosé).
Classification of spumante wines
According to the presence of residual sugar in spumante wines after manufacturing and re-fermentation, the different categories of spumante wines are distinguished.