Entire grapes are poured in to either cement or stainless steel vats. The grapes remain whole because the vatting by allowing gravity take them to the bottom of the vat.
In order to make a wine with the appellation's specific characteristics the winemaker adjusts the maceration time (4 to 10 days), the temperature (using thermo-regulation to cover a number of vats at the same time) and the bunch/juice ratio (pumping the juice from the bottom of the vat to the top). Maceration is important because it conditions the poly-phenolic structure of the wine.
Specific Characteristics of the Beaujolais Winemaking Process
Juice is released from the grapes under the bunches' own weight, this runs to the bottom of the vat and fills 10 to 30% of its volume. During maceration this volume of juice increases progressively to reach 40% to 70% of the total volume. This gives three distinct layers in the vat:
In the bottom of the vat is the fermenting grape juice which releases carbon dioxide. Alcoholic fermentation is the transformation of sugar to alcohol by yeast.
In the middle, the bunches float in the juice and macerate. The skins, which are made up of anthocyanes, tannins and aroma precursors, change consistency as they progressively release their components.
The bunches in the upper layer are in an anaerobic atmosphere made up of carbon dioxide. Intercellular fermentation takes place within the single grapes. This intercellular fermentation takes place with no micro-organisms present. The malic acid present in the berry is reduced by 20% to 50% and transformed in to ethanol (around 2% volume). This is an aerobic metabolism that produces specific aromas and decreases the wine's acidity.
The particularity of Beaujolais vinification lies in these complex fermentation phenomena that result in an exceptionally fruity wine. The higher the proportion of whole bunches the greater the anaerobic metabolism. Because of this great care is taken every time the grapes need to undergo a further stage of the winemaking process.
This takes place at the end of maceration. The juice in the vat, known as the "run off juice", is drawn off. The bunches remaining are placed in the press. Press juice, also known as 'Paradis', then runs from the press.
The end of the fermentations
The run off and press juices are drawn together. Alcoholic fermentation has finished and now malo-lactic fermentation (transformation of malic acid to lactic acid by lactic bacteria) takes place a few days later. This second fermentation makes the wine more supple and reduces the acidity. The wine has now reached its final composition.
Gravity is used to keep the bunches whole as they are carefully vatted into cement or stainless steel vats.
Seeding the must, yeasting :
Addition of selected yeasts to the must. This operation occurs at the vatting stage to ensure a good start to fermentation.
Decomposition of organic substances by enzymes, often with release of carbon dioxide and production of alcohols, acids or other complex products.
Prolonged contact of the must with the solid parts of the grapes made up of clusters and skins (or cap [see below]).
Cap, head :
Skins and other solid parts of the grapes which rise to the surface if the must during fermentation.
Pumping over :
Pumping fermenting must from the bottom of a fermenting vat to the top of the fermenting vat in order to aerate the must and to improve colour extraction and structure. This juice poured over the cap also avoids the drying out of the cap.
Temperature control :
From vatting through to the end of the fermentation, the temperature is controlled. From around 28C, the temperature is lowered progressively to end around 18C for the end of the alcoholic fermentation after pressing. This low temperature helps to keep in aromas.
Run-off juice, free-run juice :
The juice pressed by the weight of the grapes in the vat.
Extraction of the solid parts in the mix, also known as the marc. This takes place at the end of the fermentation in the vat.
The operation of applying pressure to the marc in order to extract the liquid. This is done with pneumatic presses which enables a more gentle and controlled pressing.
Press juice :
Juice obtained by pressing. This juice is more concentrated and sugary than the run off juice because it has not yet fermented. It is then combined with the run off juice to finish the alcoholic fermentation.
Malo-lactic fermentation :
Decomposition of the malic acid in wine in to lactic acid and carbon dioxide by specific bacteria. As the lactic acid is less acidic, the wines are more rounded, softer and less acidic. In Beaujolais this so called “second Fermentation” beginns a few days after the end of the alcoholic fermentation.
Consists in separating the clear part of the wine from all of the deposits at the bottom of the tank (skin, green parts of the grape) known as lees. The first extraction takes place after the end of the alcoolic fermentation, and the second after the malo-lactic fermentation.
occurs at the end of malo-lactic fermentation. The aim is to produce a good tasting wine with a good colour and to ensure good ageing.
Takes place after the filtration at the Cave from selected vats which are chosen bearing in mind that the wine must contain all of its typical characteristics.