Chemical element (O) whose Latin name Oxygenium derives from the Greek "oxys" for "pointed, sour". Actually, the name is wrong because you used the oxygen earlier for the formation of acids responsible. That hydrogen is the cause of the acid character, was recognized later. At 21%, the colorless, odorless and tasteless gas forms with the nitrogen (78%) and carbon dioxide (0.04%) the atmosphere. It is the main part in the water and also contained in numerous compounds of the earth's crust. At around 50%, it is the most abundant element on earth. It will be at the photosynthesis of the plants involved in which sunlight, water and carbon dioxide are involved. Almost all animals and most plants need oxygen to live. In high concentration, however, it is toxic to most living things. Oxygen is extremely reactive and very quickly bonds with most substances.
In the winemaking he plays either Aerobie (Presence) or anaerobic (Absence) a crucial role. On must and wine oxygen can be both positive (see under ventilate ) as well as negative (see under oxidation ). At the beginning of fermentation the oxygen provides for the multiplication of the yeasts, For this, the smallest amounts are enough to be removed from the must. Larger quantities are usually harmful. In various stages of vinification, antioxidant preservatives are used primarily sulfur compounds and also other substances used. The resulting during fermentation carbon dioxide protects against the oxygen, in the end, however, an oxidation must be prevented, otherwise inevitably arises vinegar or a spoiled, oxidized wine. This is best done with closed fermentation tanks stainless steel reached, whose whitespace optionally with inert gas (Protective gas) is filled. Alternatively, at reductive expansion a low and controlled oxygen contact deliberately allowed.
During the barrel aging Oxygen in small quantities is very important, because this contributes to the stabilization of colour and taste as well as to the natural clarification by the precipitation of unstable substances. This is especially true for the red wine preparation, in the stand out and Fill up aware of some oxygen contact is allowed. As an alternative or supplement since the early 1990s during the winemaking the so-called micro-oxygenation Applied, that is the metered addition of oxygen to the must or wine. For certain types of wine like sherry or port wine there is a conscious contact with oxygen.
An often asked question is, if and how much the wine during the bottle aging Oxygen needs or how that affects. According to studies, this may be positive in the right amount especially for red wines flavorings and colour his. This raises the question to what extent the different closures allow oxygen access: the ratio of the permeability of screw cap and cork (Natural cork) is 1 to 3 or 4. In the meantime, there are already alternative closures with controlled oxygenation. Regarding the different measures at the winemaking see below oxygen management,