The components of red wine are quite simple, made from fruit wine through natural fermentation, with grape juice being the most abundant, accounting for over 80%. Next is the alcohol formed from the natural fermentation of sugars in the grapes, generally between 10% and 30%. The remaining substances exceed 1000 types, with more than 300 being relatively important. Other important components of red wine include tartaric acid, pectin, minerals, and tannic acid.
Brewing Process
A. De-stemming: To avoid excess bitterness in the wine, the stems are removed from the fruit.
B. Crushing: The skins are gently crushed, referred to as crushing.
C. Fermentation: Yeast is added to the crushed grapes (along with skins and seeds). The color of red wine comes from the skins, while the astringency is the flavor released by the seeds.
D. Pressing: The fermented wine is pressed using a juice extractor.
E. Fermentation: The pressed wine is separated from the skins and seeds, and then only the wine is allowed to ferment. This stage is crucial in determining the flavor of the wine; fully fermented and matured wine results in different flavors.
F. Racking: After fermentation, the dissolved residual substances will automatically settle, allowing them to be easily removed. This process is called racking.
G. Aging: The wine is then placed in barrels to mature fully, with the aging period being about two years (though some may age for less than two years).
H. Bottling: After aging, the wine can be bottled.