Oxygen is one of the substances that promote wine aging. Wine aging is a slow oxidation process that causes changes in flavor and aroma, and changes the color of the wine. However, if too much oxidation occurs, the wine can become defective due to “peroxidation”. The visible signs of oxidation in a wine can sometimes have a beneficial effect, as in some Sherry and Jura wines.
In the production of wine in general, winemakers are always trying to fight against oxygen. To reduce the rate of oxidation and the risk of spoilage, most winemakers add sulfide to their wines as a preservative. So if this is the case, where does the oxygen in the aging process come from? Here by a long and much debated issue – the oxygen transmission rate of cork. One of the most debated topics is the difference between a “natural” cork and a screw cap.
Natural cork producers say that “the oxygen transmission rate of natural cork is an important guarantee of a good wine aging process, while screw caps do not do this at all”.
In order to distinguish it from a product developed by a screw cap manufacturer that transmits a small amount of oxygen through a silicon pad in the screw cap, the rate of oxygen transmission is often defined very precisely. In fact, the oxygen provided by the natural cork is only one of the ways in which oxygen is obtained during the aging of wine. Now, researchers have begun to look at more important sources of oxygen that may be present in wine. Oxygen can be dissolved in liquids, similar to the carbon dioxide present in champagne. In general, wine contains only small amounts of dissolved oxygen. At bottling, the dissolved oxygen in the wine is increased by, for example, pumping, pipeline transport and taps. Recent findings suggest that the “air pocket” between the cork and the wine is also a very important source of oxygen. This part of the oxygen is sometimes referred to as headspace oxygen (HO). How much oxygen is in the air pocket depends greatly on how the wine is bottled. However, some producers use inert gas to fill the air pockets during bottling, thus completely eliminating oxygen from the bottle. Dissolved oxygen and air pockets are the total oxygen content of the wine. Research by the Australian Wine Research Institute (AWRI) has shown that 60-70% of the total oxygen content comes from the air pockets, which account for a greater proportion of the oxygen than is transmitted through the cork. That is, the aging process of a wine depends more on how it is bottled than on the breathability of the cork.Warm Tips: Stay tuned to the LuFuture.com app for the latest market updates.
Wines,