**1. Wine freshness**

Wine freshness is an unspecific concept which includes parameters concerning acidity, aroma, alcohol content, and even color. It is also strongly correlated with fruit maturity, but the grapes from warm areas frequently have excessive sugar content that produces high alcoholic degree (>13%v/v) and low acidity (pH > 3.8). Wines produced with these grapes are normally winey, with unpleasant taste, scarce aromaticity mainly supported by higher alcohols with low levels of fruity esters, and a lack of sourness being usually less appreciated by the consumers. Moreover, these wines have a complex management during production and storage, because the low acidity produces higher sensibility to microbial spoilage and also because of the oxidation due to the low contents of molecular and free SO2. For a better management and preservation, these wines are frequently dosed with tartaric acid,

thus favoring a more suitable management which counteracts both oxidative and spoilage processes but at the same time produces a typical excessive and overperceived sourness.
