Micro-oxygenation of wine.

Micro-oxygenation is a process that consists of the deliberate and controlled addition of small volumes of oxygen to the wine throughout its production.

This technique requires specially designed equipment to control the dose and time of application of oxygen to the wine, and should not be confused with the passive exposure of the wine to ambient oxygen that takes place through the wood of the barrel during the process of aging, or in the different racking that wine undergoes throughout its production cycle, where exposure to oxygen (although it may be intentional) is not controlled.

Positive effects of micro-oxygenation on the quality of the wine.

Among the main positive effects of micro-oxygenation on the final quality of wine (Gómez-Plaza and Cano-López, 2011) include:

-Improvement of color in red wines.

-Improved color stabilization .

-Improvement of the flavor and structure of the wine.

-Improvement of the aroma and reduction of undesirable aromatic compounds.

These beneficial effects have been mainly attributed to the positive effect of oxygen on yeast metabolism during the alcoholic fermentation process, indicating an increase in yeast resistance to ethanol, which increases their fermentation capacity.

It has also been related to an increase in the formation of highly valued compounds from a sensory point of view and to the reduction of certain undesirable compounds, such as sulfur compounds.

On the other hand, it has also been pointed out that this technique helps to stabilize the color in red wines without changing their hue, preventing the loss of color that normally takes place during malolactic fermentation (Pérez-Magariño et al., 2006).

What is the necessary equipment to carry out the micro-oxygenation of the wine?

As mentioned above, this technique requires special equipment that allows a specific volume of oxygen to be added in a controlled manner to the wine, which can be supplied to the wine through automatic injection systems as determined by the winery’s oenologist ( Gómez-Plaza and Cano-López, 2011).

Micro-oxygenation systems generally have three main parts:

I  a source of oxygen,

II  a dosing system, and

III  a microporous ceramic diffuser located inside the wine tank (Figure 1).

Thus, once the volume of oxygen to be supplied is calculated, it is automatically transferred from the oxygen source (cylinder) to the ceramic diffuser (Figures 2 and 3) following what is programmed by the winemaker.

The ceramic diffuser is then in charge of converting the flow of oxygen into fine bubbles that quickly disperse in the wine, allowing it to dissolve in the wine before reaching the surface of the tank (Laurie et al., 2014).

More information on wine microoxygenation:

Micro-oxygenation of red wines

Controlled micro-oxygenation in wines