The process of making red wine
1. Harvesting
The harvested wine will contain leaves or unripe or overripe grapes, and the more serious wineries will screen the harvested wine, while the famous wineries that produce the best wines will handpick the best grapes one by one.
2. Breaking the skins and removing the stems
The color and flavor structure of red wine comes mainly from the red pigments and tannins in the skins of the grapes, so it is important to break the skins first so that the juice can come into contact with the skins to release these polyphenols. The stems of the grapes have stronger tannins that are usually removed, and some wineries leave a portion of the stems behind in order to strengthen the tannins.
3-1 Maceration and Fermentation
After the skins have been broken and the stems removed, the juice and skins are placed in vats together and macerated while fermentation takes place. Traditionally, unsealed oak tanks were used, but nowadays automatic temperature-controlled stainless steel tanks are used. Higher temperatures will deepen the color of the wine, but too much heat (over 32 degrees Celsius) will kill the yeasts and deprive the wine of its fresh, fruity aromas, so the temperature must be controlled moderately. The carbon dioxide produced during fermentation pushes the skins to the top of the vat and prevents them from being macerated. Traditionally, the winemakers would crush the skins with their feet and blend them with the wine, or they would use methods such as bongos or mechanical stirring to blend the skins; the longer the maceration, the stronger the phenolic substances, flavors, and minerals that are released into the wine. When the fermentation is completed and the maceration reaches the required level, the liquid part of the tank can be guided to other tanks, and this part of the wine is called the first wine.
3-2 Carbon dioxide skin maceration method
The wines made by this method have the characteristics of sharp color, pleasant fruity aroma, low tannin content, easy to taste, etc., and are often used to make light red wines suitable for drinking at a young age, such as new wines produced by Bauzouli in France. In principle, the manufacturing of new wines is characterized by placing the intact bunches into the carbon dioxide-filled tanks for a few days, and then squeezing them for fermentation. . In fact, due to the pressure, it is very difficult to keep all the bunches intact, and some of the pressed grapes start to ferment. In addition to producing wines with character, this method of vinification allows malolactic fermentation to be completed early, in time for the release of the new wines on the third Thursday of November.
4. Juicing
The resultant liquid from the pressing of the skins is much thicker than the first wine, with a very high content of tannins and red pigments, but a lower alcohol content. The wine can be added to the first wine as desired, but it must be clarified before being blended.
5. Cultivation in oak barrels
This process is very important for red wines. Almost all high-quality red wines are cultivated in oak barrels because oak not only replenishes the aromas of the red wines, but also provides the right amount of oxygen to make the wines mellow and harmonious. The length of the incubation period depends on the structure of the wine, the size of the barrels and the age of the barrels, and usually does not exceed two years.
6. Cultivation of wine tanks
The process of red wine cultivation is mainly to improve the stability and maturity of the wine, with heavy and harmonious flavors, and malolactic fermentation, barrel exchange, and short-term aeration are all indispensable procedures.
7. Clarification
The clarity of red wine has little to do with the quality of the wine, unless it is clouded by bacterial infection. However, for the sake of aesthetics, unless the wine is cloudy due to bacterial infection. However, for aesthetic reasons, or to stabilize the structure of the wine, the clarification process is usually carried out. Winemakers can choose the appropriate clarification method according to their needs.
8. Bottling