Where does the color of red wine come from? The answer is simple: Red wine is made from red grapes. It is the maceration of the skins in the fermenting juice that gives the wine its red color. But then why are there so many shades of color between the different red wines?
Two main reasons:
1. The grape variety that is decisive! Some grapes have richer skin color. (Pinot Noir or Grenache give slightly colored wines unlike Syrah or Cabernet-Sauvignon which produce darker wines). 2. The method of vinification which can influence the intensity of the coloring. The stronger the extraction, the more intense the color. It is the skins of the red grapes that give their color to the red wine during maceration. (Unlike the production of white wine, for which the juice does not remain in contact with the skin and seeds) After this maceration period ranging from 4 to 1 month, the juice will be extracted and fermentation will begin.
From the vine to the bottle Let’s take the time to go through the different stages of wine making: Harvest: To make wine, you need grapes! The harvest can be manual or mechanical. The grapes are harvested when it is judged to be mature. Sorting: A sorting table and the human eye are most often used to select the clusters.
Destemming: This is the first step in the winemaking process which consists in separating the grains from the stalks (the stem). The destemmer separates the grapes from the green part of the bunch which could give the wine a bad taste. Crushing: This is the second stage of vinification, we crush the berries. This consists of popping the grains without crushing the seeds. Before the grapes were crushed with the feet in a large container. Nowadays, this operation is generally done in a crusher which facilitates the release of the juice and the pulp to allow a good maceration and a good start of fermentation. Maceration and fermentation: The crushed and destemmed harvest is directed in fermentation tanks. After having brewed the must (juice + pulps + skins + seeds), a sulphiting operation is carried out in order to prevent the oxidation of the harvest. Then we add yeasts in addition to the natural yeasts contained in the grape so as to start fermentation. During maceration, the must will therefore ferment.
The alcoholic fermentation begins and lasts on average four to ten days. During fermentation in tanks, the yeasts transform the sugars into alcohol and carbon dioxide. The latter escapes to the top of the tank, causing solid parts (skin, seeds and pieces of pulp) which will form a 'cap' above the fermenting juice. This cap contains several elements that interest us, particularly the tannins, pigments and aromas. Little by little, these colored pigments which are called anthocyanins diffuse in the must in fermentation. Depending on the type of red wine sought, the maceration will be more or less prolonged. Indeed, the red wines of guard require a longer maceration in order to obtain a good structure and an aptitude for aging. Their color is then more intense.
Operations during fermentation: In order to promote the extraction of color, tannins and aromatic compounds contained in the skins, care must be taken to regularly mix the solid part and the liquid part. There are several operations. Reassembly: To extract the solid parts and recover them in the wine, we are going to work the cap. For this, the fermentation juice is pumped upwards to water and aerate the wine for better yeast work. Another technique, punching down: this consists of gently pressing the marc cap into the juice to develop the fruit and reduce the tannins. Racking: After fermentation, the juice flows down from the fermentation tank to another tank. By gravity, the wine is separated from the marc (all of the solid parts of the grape: stalks, dandruff, seeds, still impregnated with alcohol). The wine sold is called "drop wine". Pressing: The skins and seeds recovered from the tank go to the press to remove the soaked wine. This pressing gives the "press wine" richer in color and tannins. Depending on the type of wine sought, the latter is reintegrated into the “drop wine” for a second fermentation called malolactic fermentation. It naturally reduces the acidity of the wine and gives it more roundness.
Aging: The wine is then stored in barrels or in another tank for two or three seasons during which it will evolve. The choice of these containers is crucial because it determines whether the wines will simply oxygenate or be marked by the taste of wood. In oak barrels, there is an exchange of aromatic and gustatory substances from the wood to the wine. Micro-oxygenation provides oxygen which helps stabilize the color of the wine. For the balance and complexity of the finished product, the assembly is a final step: we assemble several cuvées from different plots, or even from different grape varieties (when it is not a single-varietal wine). The winemaker can also choose to make his wine more radiant by fining (addition of egg white) and more clear by filtering which stabilizes the wine.
Bottling: This stage completes the aging process for the marketing of the product.