Red wine vinification by maceration
Red wine vinification by maceration is the biochemical process that transforms the grape into wine. During red wine vinification by maceration, a chemical reaction occurs, which is activated by ripe grapes and the yeast in their skins.
After removing the stems, the grapes are squashed in a mill. The resulting mixture of fruit pulp, skins, seeds and juice is the so called mash. This process is called mashing.
In the mash of red wine a fermentation process takes place. This means, must, fruit pulp, skins and seeds are fermented. The mash fermentation can last several days to weeks. Thereby, colour pigments are extracted from the skin to form tannin. Tannins determine the durability of red wine but can also lead to a bitter taste. The lower the fermentation temperature, the slower the mash ferments. After the fermentation, the mash is pressed through the wine press.
The largest part of the red wine flows off without pressing. The so called press wine contains much more tannin than the free-run wine. Afterwards, the fermented wine is stored 6 to 18 months up to several years in oak barrels or stainless steal tanks to ripe.
Most red wines can be stored up to 4 years without any negative quality changes. Some are even drinkable after 10 to 100 years, depending on the kind of grape.
Maceration during red wine production is the removal of colour and pulp from the skin while and after the fermentation process. The optimal fermentation temperature is about 25 degrees Celsius. The marc (consisting of pulp, skin and seeds) moves up to the surface during the fermentation and forms the so called cap. The cap is constantly mixed with the must by deducting the wine from the bottom of the container and pumping it on the cap again. Another possibility is to push the cap from the top to the bottom.