Geisenheim Research Center,
Section Enology and Wine Technlogy
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
The final step in winemaking – the
bottling process – has a significant
impact on the content of dissolved oxygen
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.
IMPACT ON OXYGEN CONTENT IN WINE
PRIOR TO BOTTLING
into a wine may vary, depending on
wine composition. In Figure I, oxygen
uptake changes depending on different
enological treatments prior to 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.
IMPACT ON OXYGEN CONTENT IN WINES
WITH DIFFERENT FILLING SYSTEMS / PROCEDURES
Ideally, the bottling
process should flow smoothly
with a simple and economical system
in order to microbiologically protect
the wine and to conserve wine quality
and its sensory characteristics.
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).
RELEVANCE TO COMMERCIAL WINEMAKER?
Generally the evolution of gases
can be described by Boyle’s-Law “P x V =
const.” During bottling, there are several
gases (O2,N2,CO2) in the head space of the
bottle and in the wine itself. Interactions
between these gases and the liquid in the
bottle can be influenced by using different
filling systems or procedures.
Figure I: Impact of different enological treatments on oxygen uptake prior to bottling.