xygen plays a crucial role in enology, and in the wine. Louis Pasteur noted that oxygen can make or break a wine. Oxygen management in wine thus represents a key component to maximize wine quality in relation to different markets and types of consumers.

Oxygen can dissolve in wine at several stages during winemaking, bottling and ageing. From a chemical perspective, its presence could result in wine oxidation, and thus change the quality and the extent of a wine’s life. Whereas extensive oxygen exposure might be the cause of serious defects, slight to moderate oxidation might benefit a wide range of wines, particularly reds. Carefully managing oxygen is a critical control factor during wine production.

The final step in winemaking – the bottling process – has a significant impact on the content of dissolved oxygen in wine.

Compared to other enological processes, the increase of oxygen before, during, and after bottling is relatively low. However, it is a very important stage because after sealing the bottle, a winemaker’s influence on the physically or chemically-dissolved oxygen in a wine is minimal. Therefore, the winemaker has to consider and define how he or she wants a wine to develop during storage before the actual moment of bottling.

The first input of oxygen in the bottling process can occur when unloading wine from a tanker truck, and consequently during blending, fining, cooling, filtration, and immediately before bottling by pumping wine into the filler.

In addition to temperature, bottling pressure is a concern that occurs when inserting a stopper into a bottle. If you do not use a

vacuum pump or insert CO2 into the headspace to reduce oxygen content, oxygen uptake will likely increase during bottling. Other elements influencing oxygen uptake during bottling are time and compounds in the wine itself (enzymes, katalytes [Cu or Fe] and redox system).

Figure I: Impact of different enological treatments on oxygen uptake prior to bottling. [Deutsch, 1980]