See under Pressing.
Term (also winepress) for both the process of pressing grapes and the mechanical equipment needed to do so. Presses were already used in early antiquity, as evidenced by finds of several thousand-year-old artifacts in many ancient wine-growing regions. Among others, the Roman writer Cato the Elder (234-149 B.C.) reports about it in his works. Pressing is a crucial step in the winemaking process. As a rule, only healthy and physiologically ripe grapes should be processed, which is achieved by appropriate preliminary work such as selective grape harvesting. Depending on the type of wine, a decision must be made as to whether destemming (destemming, de-stemming) should take place before pressing, i.e. whether the grape skeleton should be removed. During pressing, the grape must is separated from the grapes by mechanical pressure. Depending on the type of wine, it is separated from the solid components and then processed further, especially in white winemaking, where pressing is usually the first step. In red win emaking, this is done only after the classic maceration.
If the crests are also pressed, they release tannins (tannins) and pigments (colorants), which can be quite desirable for grapes with a strong fruity flavor or is common in red winemaking, for example, through the technique macération carbonique. The grapes should be processed as gently as possible by minimising mechanical influence, in order to keep the undesirable trub content (smallest suspended substances from berry skins and fruit pulp) and the tannin content in the must as low as possible in white wine production. Modern cellar technology therefore tries to use natural gravity instead of pumping processes to move the grapes and must. Each pumping process increases the lees content by up to 1%. Pneumatic tank presses are the gentlest in this respect.
By using pneumatic presses and frequent whole bunch pressing, intact grapes are processed, as the gentle pressing process does not crush the crests and there is no danger of too much tannin in the must. Depending on the variant, the grapes (with or without combs) are then crushed or ground, thus breaking up the berries and facilitating the release of juice. The desired intensity can be variably adjusted. An ancient form of crushing is stomping the grapes with bare feet in a container. This is still common today, especially in southern countries, for example in the production of port wine. The result of destemming and crushing is called mash. In red wine making, mash fermentation now begins without pressing, while...