Term (also pressing) for both the process of pressing grapes and the mechanical equipment required for this. Presses were already used in early antiquity, as evidenced by artefacts dating back several thousand years in many wine-growing regions. Among others, the Roman writer Cato the Elder (234-149 BC) reports on this in his works. Pressing is a crucial step in the winemaking process. Only healthy and physiologically ripe grapes should be processed through selective harvesting. Transport to the cellar should take place as quickly as possible and without mechanical stress in shallow containers.
Destemming yes or no
Depending on the type of wine, a decision must be made as to whether destemming (destemming, destemming) or removal of the grape skeleton should take place before pressing. 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 wine production, where pressing is usually the first step. In red wine production, this is only carried out after the classic mash fermentation. If the ridges are also pressed, they release tannins or tannins and pigments (colouring agents), which may be desirable for grapes with a strong fruity flavour and is common in red wine production, for example using the carbonic maceration technique.
Gentle processing
The grapes should be processed as gently as possible with as little stress as possible in order to minimise the undesirable lees content (tiny suspended particles from berry skins and pulp) and the tannin content in the must. Eachpumping over increases the lees content by up to 1%. The advantage of moving the grapes and must is that natural gravity is used instead of pumping. By using pneumatic presses, there is no risk of too much tannin in the must. Depending on the variant, the grapes (with or without combs) are then crushed or ground, breaking up the berries and thus facilitating the release of juice.
Crushing
An ancient method is to crush the grapes with bare feet in a container. This is still common today, especially in southern countries, for example for port wine. The result of destemming and crushing is known as the mash. In red wine production, mash fermentation usually takes place without pressing, while pressing is used for white wine production. To optimise the fermentation process, the must must be treated accordingly.
Pressing systems
The mechanical device required for pressing is called a press or wine press. In...
