Vacuuming

Term for the process of extracting air (oxygen) from a container or packaging and thus creating a vacuum. The liquid or food contained in the container is thus made more durable, because any microorganisms contained in the air are also removed. In viticulture, this prevents or at least limits oxidation or spoilage of the wine. There are also small hand pumps that can be used to protect opened wine bottles from spoilage and/or taste impairment. Vacuuming belongs to the large group of numerous preservation measures. There are the following applications:

• Alcohol reduction - through vacuum distillation (vacuum rectification).
• Stages - sterilisation and cleaning of barrels
• Extraction - vacuum extraction
• Filtration - vacuum filtration
• Bottling - vacuuming the empty space in the bottle neck
• Concentration - vacuum concentration
• RCGM (concentration of grape must) - vacuum evaporation

Vacuum

Vacuum refers to a space with a virtual absence of matter. In a vacuum there are no solid objects or liquids, only extremely little gas and therefore an extremely low gas pressure. In engineering and experimental physics, the term vacuum refers to the state of a gas in a volume at a pressure much lower than atmospheric pressure at normal conditions. However, an absolute vacuum does not exist in the entire universe. A distinction is made between rough vacuum, fine vacuum, high vacuum and ultra-high vacuum. Creating a vacuum is also called "evacuating". In vacuuming, not even a rough vacuum is generally achieved. The picture on the left shows the "Magdeburg hemispheres" of the German physicist Otto von Guericke (1602-1686). He demonstrated the effect of vacuum as early as 1657. Picture on the right shows a glass bell jar with a piston vacuum pump for school experiments.