How is wine made? Let’s start by talking about the winemaking process. There are seven steps in the process: picking, sorting, crushing, maceration, fermentation, ripening and bottling.
The farmer will regularly observe the grapes and calculate the best time to pick them. Grapes are picked manually and mechanically. Manual picking is slower, but reduces the damage to the grapes during the sorting process. Mechanical sorting is more efficient and can enter the winemaking process during the golden hour.
After sorting unripe and rotten grapes, one removes the stems of the fruit. The stems contain a large amount of tannins. Some wineries add a few ripe stems to add tannins to the flavor.
The earliest traditional process of extracting juice from damaged skins was actually by foot stomping! This was done to prevent the destruction of the bitterness caused by the grape seeds. Grape skins contain natural yeast. During the pressing process, the natural yeast in the grape juice promotes the conversion of sugar to alcohol and the start of natural fermentation. As for the bacteria we are worried about, they are eliminated by the weak acidity of the grapes and the alcohol.
Afterwards, the must is macerated at low temperature for a period of time to extract the tannins, pigments and fruit flavors. The longer the maceration time, the higher the extract content. Sometimes, fermentation and maceration take place at the same time. Yeast converts sugar into alcohol and carbon dioxide, and the must becomes wine. The carbon dioxide pushes the grape skins to the top of the wine tank. The winemaker will touch the skins and must several times, both manually and with mechanical assistance, to allow for a more thorough maceration and fermentation process.
After alcoholic fermentation, the malic acid in the wine is converted to softer lactic acid. In addition, sulfur dioxide is added to the wine’s list of ingredients at this time. Sulfur dioxide not only prevents rancidity, but also isolates the wine from the air and slows down the oxidation of the wine.
After fermentation, the wine is filtered for solid impurities and transferred to oak barrels or stainless steel tanks. The different barrels and aging times determine the wine’s unique flavor and structure, while the stainless steel tanks will retain the wine’s own fruity aromas.
White wines and red wines are made in a similar process. It is the anthocyanins in the grape skins that give the wine its deep red color. Wine is fermented on the skins, while white wine is fermented on the skins. During the fermentation process, when the must is not in contact with the skins, the filtered wine does not have a deep red color. White wines are made from white grape varieties, but some wineries also use skinless red grape varieties to make white wines.
Many wineries with high quality requirements still choose the manual method for many of their processes. Although this method is more costly and less efficient, the quality of the wines produced is better.
