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 of this transposition to the human situation hinges on the double meaning of 'unripe' ("vert") in French, which could also be used of a sexually immature female. From this emerges the story's subtext, of which a literal translation reads: There is the same sexual ambiguity in the Greek of Babrius. The phrase there is "όμφακες εισίν" ("omphakes eisin"), the word "omphax" having both the literal meaning of an unripe grape and the metaphorical usage of a girl not yet ripe for marriage. Rather than admit his failure to reach the grapes, the fox rationalises that they are not really desirable.