Increased color intensity
Oxygenation at the end of AF on wines under marc, or after run-off, increases color intensity.
Once oxygen has been added, color intensity evolves in the same way as for non-oxygenated wines, but retains a higher color intensity.
Decreased perception of veggie notes
Reduced veggie note perception is one of the effects sought by micro-oxygenation users.
It has been observed in most of the trials and projects we have carried out over the last twenty years.
Figure 2: Evolution of "veggie" note perception during micro-oxygenation aging
Softening of tannins and increase in roundness
The impact of micro-oxygenation on tannins is one of the most sought-after benefits for red wines. Controlled oxygenation reduces tannin reactivity (which gives tannins a rustic attribute) and progressively coats them.
This sensory phenomenon is explained by the transformation of reactive tannins into firm tannins, with an increase in the perception of fat, which gives the wine its coated character.
Synergistic effect of aging white wines on lees
Oxygen is also synergistic with lees aging in white wines. It helps to increase the perception of volume, especially for intakes comparable to those in the barrel (below 1 ml/l/month).
It also helps to increase astringency, which can be interesting for wines with soft balance, but must be taken into account for wines with balanced acidity (more aggressiveness).
Integration of oaky notes
In many markets, the trend today is towards wines with a mellow oak character.
This is another advantage of oxygenation: for wines aged in contact with oak, the oaky notes are better integrated.
This integration varies according to toasting level. The impact of oxygen is greater on unheated oak and strong toast than on intermediate toast levels.
In summary, the qualities of micro-oxygenation are recognized in:
- increased color intensity;
- reduced perception of veggie notes;
- softening tannins and increasing roundness;
- synergy with aging on lees in white wines;
- integration of oaky notes;
It should be noted, however, that the expected effects can only be achieved if the technique is well mastered.