Gas – the good spirit of wine
Wines with a fresh, fruity character are in high demand these days. Essential to their production are quick and careful wine preparation, must purification, controlled fermentation and oxidation, as well as thorough hygiene. One noticeable development in the wine technology of today is the growing interest in gas applications.
The use and combination of gases depends on the character of the wine and the expectations of the consumers. Carbon dioxide is particularly suitable for the treatment of rosé and white wines. For red wines, on the other hand, nitrogen is used to a greater extent. The gases that are used in the treatment of wine can be divided into two groups. The first group includes inert gases such as nitrogen and argon. They do not react with the individual components of the wine. The second includes gases such as oxygen and carbon dioxide, which influence the character of the wine.
Nitrogen and carbon dioxide are used in winery management. Both gases are used separately as well as in combination with each other. Carbon dioxide, however, dissolves much more readily in liquids than nitrogen.
Wine growers can use gases in the various stages of wine production – from the grape harvest through to improving the shelf life. Here is an overview:
If temperatures during the grape harvest are over 25 degrees Celsius, there is the danger that the grapes will start to ferment prematurely. Here, the use of carbon dioxide snow offers the ideal solution for cooling the grapes. The advantage of this method compared with normal ice cooling is that there is no water formation when carbon dioxide snow melts.
The removal of the atmospheric oxygen from the must provides microbiological protection against oxidation and prevents premature fermentation. This is done by either putting dry ice pellets directly into the press or adding them to the prepared must.
The technology of cold maceration facilitates an enhanced extraction of fruit aromas. With this process, the wine growers prolong fermentation through low must temperatures. In order to prevent oxidation, they treat the ripe, healthy grapes with carbon dioxide prior to processing.
Flotation technology is one of the most modern methods of must purification. During this process, the must is continuously filtered before being mixed with nitrogen or carbon dioxide in a pressureresistant container. Finally, the must is exposed to atmospheric pressure. This pressure causes the clear liquid to be separated from the suspended solids.
The inerting of tanks – the removal of atmospheric oxygen from the liquid – provides protection against oxidation. Carbon dioxide in the form of gas or snow is used for white wine. Nitrogen or a mixture of nitrogen and argon is used in red wine tanks.
Wine growers use carbon dioxide to freshen the wine. This creates a fresher taste and fruitier aroma.
Carbon dioxide is used for the effective mixing of different vintages or types of wine. This prevents oxidation of the different wines.
Bottling and gastronomy
A special gas mixture also offers oxidation protection after the bottle is opened.
Vinocor, the invisible cork – protective gases in modern winery technology in Austria
In Austria, too, quality-oriented wineries are increasingly using protective gases in wine production.
In particular, high-purity nitrogen and Vinocor, a mixture of high-purity nitrogen and carbon dioxide, are used.
The Federal Office of Viticulture in Austria has tested Vinocor and confirmed that the wine retains its very good quality for two to three weeks if Vinocor is added within a few hours of opening.
This procedure avoids the changes in taste and color caused by oxidation and preserves the existing quality of the wine.
The Vinocor-Gastro appliance is specially designed to meet the needs of the professional user. It is extremely robust and can either be mounted on a wall or a stand. A hose line connects it to the gas cylinder containing the gas mixture. In almost every case the gas cylinder is situated directly under the bar. Dispensing of the gas is electronically controlled.