There are operations common to the various winemaking processes
Harvest: For a long time, the harvesting machine (a large truck that goes into the vineyards) which has made great progress is increasingly used. Nevertheless, it remains partially or totally prohibited in certain regions: Champagne, Beaujolais (for primeur wines), or for certain types of wine: late harvests, selection of noble grapes.
Mechanical treatment of the harvest
Crushing: This is the operation that consists of breaking up the grains without crushing the seeds and stalks. The crushing allows a good maceration (for red wines) and a good start of fermentation. It is not practiced in the vinification of black whites, nor for carbonic maceration because for these two types of vinification the grapes must be whole when they arrive at the press. For the black whites or at the time of the setting in tank for the carbonic macerations.
Destemming or Destemming: This is the process of separating the stalks from the rest of the harvest. The destemming allows to obtain softer, less astringent wines and a higher alcoholic degree.
Pressing: This is the operation that extracts the liquid from the solid parts of the harvest. Important, for red wines, this operation takes place after maceration and total or partial alcoholic fermentation. In this case, the wine comes out of the press. For the white wines, there is no maceration, the pressing takes place before the fermentation. In this case, it is the must that comes out of the press.
Sulphiting: this is the operation which consists in bringing a certain quantity of sulphur dioxide (SO²) to the harvest. It allows :
-to select the fermenting medium.
- to facilitate clarification, because by delaying the start of vinification, it favours settling of the must.
- to acidify the must.
- to delay oxidation, in particular the maceration of white wines and the oxidasic breakdown caused by an enzyme called oxidase.
If used incorrectly or in too large quantities in a given year, SO² can produce hydrogen sulphide (H²S), which has a characteristic smell of rotten eggs.
Yeast: Yeast is added at full activity. Yeasting allows a good start and a better control of the fermentation.
Summary of the different winemaking operations
Red winemaking
It is made from red grapes. These are usually crushed and de-stemmed. The harvest thus crushed and de-stemmed is put into vats, generally made of stainless steel, sometimes cement or wood.
Alcoholic fermentation then begins. It is imperative to monitor the temperature. Maceration takes place at the same time as the alcoholic fermentation. It is during the maceration that the colouring matters contained in the skins will dissolve and colour what is becoming wine. This maceration is more or less long depending on the wine you wish to obtain. It is short, only a few days, for light wines, to be drunk young. It is long, a fortnight to three weeks, for wines that are to be kept. Indeed, a prolonged maceration allows a better extraction of the different constituents of the grapes, in particular the tannins. The tannins play a role in the structure and conservation of the wines.
When the alcoholic fermentation is finished, the wine must be devatted. The liquid contained in the vat is allowed to run off: this is the Free Run Wine. Then the solid parts impregnated with liquid are sent to the press. The wine that comes out of the press is the Vin de presse. The winemaker decides whether or not to blend these two types of wine which have different characters. The red wines then carry out their malolactic fermentation.
The vinification of rosé wines
Either "Rosé de saignée" or "Vin gris".
If, after a few hours of maceration, juice is taken from a vat intended for the elaboration of red wines, this juice is barely coloured. It is then enough to let it finish its fermentation without contact with the skins to obtain a rosé wine. Only Champagne is authorized to blend a white wine and red wine to obtain a rosé wine.
Some rosé wines are obtained without maceration: grey wines. For this type of wine, the reds are vinified like white grapes. The colouring, which is not very strong, comes from the bursting of the skins during pressing.
White wine making
It is generally made from white grapes (blancs de blancs), but as we have also seen previously, it is possible to make white from red grapes (blancs de noir) as is regularly done in Champagne. The essential difference between red and white winemaking is the fact that, in the case of white winemaking, there is no maceration (some exceptions with a very short particulate maceration). The grapes are taken directly to the press. The juice ferments without contact with solids (skin, pips, ...). It is important to remember that in the case of a red vinification, it is wine that comes out of the press, whereas in a white vinification, it is grape juice.
Observations
Whatever the type of winemaking, young wines are generally cloudy. Various operations are necessary before delivering them for consumption: filtration or fining, racking, etc. During storage, prolonged contact with the air must be avoided, which leads to ouillages. These various operations are often grouped together under the term "essential care".
Sparkling wines
French production of sparkling wines is around 450 million bottles per year. These wines are characterized by the more or less important presence of carbon dioxide (carbon dioxide: C0²).
...so we find:
* Carbonated wines
* The other sparkling wines.
These wines can be made according to different methods:
- Rural or ancestral method
- Closed tank method, known as the Charmat method.
- Traditional method (long known as the Champagne method)
Among these wines, a distinction must be made between :
Sparkling wines: which have a suppression equal to or greater than 3 bars at a temperature of 20°C.
Semi-sparkling wines, which have a suppression equal to or less than 1 but not more than 2.5 bar at a temperature of 20°C
Different elaboration processes
Carbonated wines (sparkling or sparkling)
They are obtained by adding industrial CO². This process does not make it possible to produce high quality products. These wines, whose effervescence is obtained (even partially) by the addition of carbonic acid that does not come only from their own fermentation, must be labelled "sparkling (or semi-sparkling) aerated wine".
Rural or ancestral method
This is a very old process, used long before the traditional method. Contrary to the traditional method, it does not have the addition of draught liquor (sugar + yeast). During fermentation, cold or repeated filtration and racking are used to preserve some of the sugars contained in the must. The wine is then bottled. As soon as the conditions become favourable again, fermentation starts again. C0² is therefore produced from natural grape sugar. This method can still be found in some regions: Limoux, Die, Bugey, Gaillac... Be careful not to confuse: Crémant de Limoux, Blanquette de Limoux and Blanquette ancestrale, Crémant de Die and Clairette de Die.
In the region of Die (Drôme), the Dionaise Naturelle method is used. Its principle consists in slowing down the fermentation of the juices by the cold so as to preserve in the wine enough natural sugar of the grape and to privilege the aromatic aspect. The wine is bottled where a second fermentation takes place without any addition. This method uses only physical processes (cooling and filtration).
Closed vat known as the "Charmat method".
The first phase of this method consists in making a still wine. Then sugar and yeast are added. A second fermentation takes place. As its name suggests, and contrary to the traditional method, this second fermentation takes place in vats. In terms of quality, the results obtained by the traditional method are similar to those obtained by the traditional method, but it allows the rapid production of sparkling wines with a much lower cost price.
The traditional method
long known as the "champagne method"
In France, this method is used for the elaboration of Champagne and quality sparkling wines, especially those with an AOC (Créments, Saumur, ...). As with the previous method, a still wine is made, then sugar and yeast are added (liqueur de tirage). But the second fermentation takes place in bottles. Therefore, it requires many manipulations, which obviously increases the cost price. Among these manipulations are riddling and disgorging. This method makes it possible to obtain sparkling wines of excellent quality. The price difference with wines obtained by the closed vat method is fully justified.
At the EU level, sparkling wines are classified as :
-Sparkling wine
- Quality sparkling wine
- Quality aromatic sparkling wine
-Aerated sparkling wine
- Sparkling wines
- carbonated sparkling wines
For these last two categories, the legislation of the producing country may be more restrictive than that of the E.U., France, for example the minimum period of conservation in the cellar is 15 months whereas the E.U. imposes only 9 months for wines of the same category.
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