Once the grapes enter the winery, pressing is performed, a process that was formerly done with the feet. Today the pressing is done using crusher/destemmers, machines that separate the grape from the stem (the vegetal part of the bunch), and then carefully crush the grapes.
Key Process: Alcoholic Fermentation
Once the crusher/destemmer machines have separated the grapes from the stem, the must (i.e. grape juice in the case of whites, and grape juice with skin and seeds in the case of red) is placed in stainless steel tanks.
Alcoholic fermentation, which is the essential mechanism by which grape juice becomes wine, occurs in these tanks. In simple words, it is the transformation of the sugar in the must into alcohol by the action of microorganisms called yeast.
Generally, fermentation takes about 8 days at a temperature of 28°C to 30°C in the case of red wine, and 20 days at a temperature of 14°C to 17°C in the case of whites.
Vinification of Red Wines
In the case of the red varieties, during fermentation another process called maceration occurs, which is to leave grape juice in contact with the skin and seeds for a while to extract the tannins that will give body, color and flavor to the wine.
There are several types of maceration; it can even happen before fermentation, which is known as cold maceration.
During maceration a pomace hat appears, which floats on top of the juice. To obtain more substances from the skin and seeds the next step is pumping over, which consists of extracting the juice from the bottom of the tanks with pumps and place it on top, breaking the pomace hat in the process.
For red wines, winemakers carry out a second process of malolactic fermentation, where some bacteria -called lactic- turn malic acid (found in the pulp of grapes) into lactic acid. Through this process wine loses acidity, softens and develops special flavors and aromas.
Although this fermentation is characteristic of the reds, winemakers occasionally use it in the production of some whites.
Vinification of White Wines
The vinification of white varieties differs from the reds in the fact that the grape juice does not ferment in contact with the skins.
Thus, the process of pressing and crushing must be done as quickly as possible in order to avoid the juice to be in contact with solid parts of the grapes, something that requires an excellent organization in the winery.
Once the skin and seeds are separated, fermentation begins at a lower temperature than reds, happening around 14°C and 17°C. The cold slows the action of yeast, and the process takes about two weeks.
Time for Devatting
Once fermentation is over, and when the wine has acquired the desired characteristics, the winemaker does the devatting.
It is at this time when mixes or assemblages are done, bringing together wines from different tanks that have acquired different characteristics. For example, some may exhibit notes of red fruits such as plums, strawberries or raspberries; others, black fruits such as blackberries and blueberries, and some chocolaty or spicy, or with hints of coffee, cassis and menthol.
The Wine Goes Into the Bottle
Once the mix is decided, the wines are clarified -or cleared of lees and yeast- and bottled.
Time for Aging
Most reds are enriched with some time in French oak or American oak barrels, where the wine gains new flavors like smoky notes, vanilla, coffee and chocolate, as well as increased concentration and tannic sensation in the mouth.
Then comes the bottling, and later the wine is stored in cellars with controlled humidity and protected from sunlight.
Time to Enjoy
Time will do the rest and it will dictate the quality of a wine. Before tasting it, we recommend uncorking the wine some time in advance and letting it breathe, because inside the bottle there is a reductive atmosphere that diminishes the aromatic expression of the wine.
A couple of hours will be enough for the wine to express itself and show all its virtues, and so reflect all the work behind the art of making wine.