Acids in wine ripened grapes. While concentration varies among grape varieties, it is usually found in higher levels with red wine grapes. The acid is created as a byproduct of the metabolization of nitrogen by yeast cells during fermentation. The combination of succinic acid with one molecule of ethanol will create the ester mono-ethyl succinate responsible for a mild, fruit aroma in wines. Acidity is highest in wine grapes just before the start of "veraison", which ushers in the ripening period of the annual cycle of grape vines. As the grapes ripen, their sugar levels increase and their acidity levels decrease. Through the
The Fox and the Grapes Phaedrus (IV.3) which is terse and to the point: In her version of La Fontaine's Fables, Marianne Moore underlines his ironic comment on the situation in a final pun, "Better, I think, than an embittered whine". Although the fable describes purely subjective behaviour, the English idiom "sour grapes" which develops from the story is now often used also of envious disparagement to others. Similar expressions exist in other languages, but in the Scandinavian equivalent the fox makes its comment about rowanberries since grapes are not common in northern latitudes. The French fable of La Fontaine (III.11) is almost as concise