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 the finished product was exhibited. Another domestic use for the fable was as an architectural medallion on the outside of mansions, of which there is still an example dating from the turn of the 19th century on the Avenue Felix Fauré in Paris. A medallion of another kind, cast in bronze by Jean Vernon (1897–1975), was produced as part of his renowned series based on the fables in the 1930s. That of "The Fox and the Grapes" features two foxes scrambling up a trellis with what looks like more success than La Fontaine's creation. There was as diverse a use