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"Entwicklungshelfer" des Weins

The filling in air tight glass bottles prevents contact with oxygen – and therewith oxidation. By contact with excessive oxygen wine may lose its freshness and potentially change its colour – and finally cant over. Indeed there remains one weak point: the opening. As nearly ideal closure cork, which has been taken from the bark of the cork oak, has proven.

Cork is elastic fits accurately in the bottleneck and thus prevents leakage of the wine. At the same time it allows a minimal exchange of oxygen – the wine is able to age, without oxidation and loses only least quantities of liquid by evaporation. In the ideal case the cork may be denoted  “development worker“ of wine. Indeed this can only be considered for superb high-quality corks.

Cork consists of tiny, self-contained cells, acting like an air cushion. In their inside there are scentless gases situated. High-quality corks should derive from cork plates, having at least seven years of age. They must be processed accurately and measure at least 45 mm. The durability of high-quality corks amounts to 20 to 25 years, their decay begins subsequently. This signifies for the wine: it must be newly corked.

Taste of cork. Cork is often bleached and sterilised in a chlorous solution. These solutions react with the phenols (molecules from dyes, tanning agents and flavour additives), that are part of every natural cork. The resulting product again reacts with moulds, “cavorting” everywhere. The result is a cork, smelling musty, which passes this stench on to the wine. Even unbleached corks are afflicted with that, as chlorine (for example in tap water) and also moulds are situated throughout the environment.

Wine should be stored horizontally, not upright.  A Cork, being too dry and hard to pull, does not have to affect the quality of the wine. It can crumble though, while the bottle is being opened. Crumbs may reach the wine; these however don’t have any influence on the wine, just pour off a lacing. Molded or black steads at the upside of the cork are of no importance and don’t have any effect on the wine. They are caused by a moist cellar.

Cork is made from the bark of the cork oak, growing in the Mediterranean area. After peeling, the bark is being stored a half year or up to two years. At the quality evaluation mere about the half is being allowed for the fabrication of the wine corks. Hereafter the cork is boiled in hot water, to make it elastic. Thereby the tannins also part. After the pressing, the cork is covered with paraffin or silicone, in order that it slips better into the bottleneck.

Highest quality – and most expensive – corks consist of one whole piece and have few pores and rifts. They feature highest elasticity and durability. For simple wines, agglomerated corks are being used. Exception: The champagne cork is made from cuttings.

Cork has become scarce; the raw material does not grow as fast as the demand does. The reason: the permanently increasing number of bottlers. Scarce raw materials become more expensive. The consequence: the bark is less strictly selected – the portion of wine being cork-sick is rising. 5% faulty cork are considered as mean value today. Plastic cork is an alternative. The plastic cork is built up similarly like the natural cork – airtight, elastic cells guarantee elasticity and density. Contrary to the natural cork it does not hold any risk of error. Important for the consumer: with the plastic cork, they don’t have to forego the sensual “plop“ whilst opening the bottle! Indeed, bottles with plastic corks should be stored upright.

For wines, consumed immediately, that are not being destined for storage, a screw-top is also a good solution to prevent cork taste (vide open wines in the gastronomy).


Classic wholebody corks

are better, concerning quality and elasticity, than agglomerated corks.

Good value agglomerated corks

consist of glued corkcuttings

Sparkling wine corks

joined from agglomerated corks and plates from whole body corks


popular closure for simple wines


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