In short, there is the fear that wine can turn into vinegar or reveal unpleasant aromas. For this reason, in our article, we decided to answer all these questions.

Why does wine turn into vinegar? Why does wine taste like vinegar?

Let’s start with two questions: why can wine become vinegar? Why can wine have a vinegar smell and taste? We tell you that this phenomenon occurs due to the action of "Acetobacter", a kind of bacteria that, in the presence of oxygen and at high temperatures, are able to transform alcohol, or rather ethanol contained in wine, in acetic acid, leading to the deterioration of the wine.

The chemical process that leads to the formation of acetic acid, through the oxidation of ethanol by acetic bacteria, is the "acetic fermentation". We would like to emphasize an aspect that will be very useful to us: this transformation activated by Acetobacter can only take place in the presence of oxygen, when the wine is put in contact, for a long period of time, with air and at high temperatures.

Acetic fermentation occurs in the production of vinegar, perfect for food use and to give flavor to food, while it must be avoided in the production of wine, representing a deterioration factor.

When does wine turn into vinegar? When does wine taste like vinegar?

Acetic fermentation and the transformation of ethanol into acetic acid can take place mainly in two phases: during the production of wine, in the fermentation phase, or at the end of the production, especially when the bottle has been opened for some time and badly preserved or stored.

Depending on when acetic fermentation occurs, this fault can be caused by a bad management of the wine by the producer or the consumer.

The formation of acetic acid can also occur at another time, much less frequent, but possible, and by another species of bacteria. These are the "Gluconobacter", which always act in the presence of oxygen directly on the grapes, when they are damaged or attacked by mold, or even on the oxidized must, transforming glucose into gluconic acid and acetic acid.

How to prevent wine from turning into vinegar?

To answer this question we have to remember what we wrote above: acetic bacteria are activated only in the presence of oxygen and at high temperatures (above 20-23 months approximately). To avoid activating acetic fermentation, it is necessary to prevent the wine from being in contact with air and oxygen for a long period of time. It is also necessary to prevent the production and storage of wine at high temperatures.

For the consumer it will be very important to follow the basic rules for a correct storage of the wine and, in particular, in the case of a bottle already uncorked, to follow the rules on how to store opened wine bottles: re-capping the bottle, decanting the wine in bottles, always to limit the contact with oxygen, placing it in a dark and cool place and at a temperature of 14-15 ºC.

The producer must not create the necessary conditions for acetic fermentation, avoiding the prolonged contact of the must/wine with the air and activating fermentation in environments with controlled temperature.

The hottest questions right now have an answer.