Harvest (wine) of wine, winemakers would use the sugar and acid levels of the grape as a guide in determining ripeness. Early winemakers tasted the grapes to gauge ripeness. Modern winemakers use a refractometer to measure high sugar levels and °Brix or titration tests (using an indicator such as phenolphthalein) to determine the titratable acidity within the grape. In recent times there has been more of an emphasis on the "physiological" ripeness of the grape, usually in the form of tannins and other phenolics. Currently, tasting is the only way to measure tannin ripeness, which can take experience and skill to do
The Fox and the Grapes in the labyrinth of Versailles. He can therefore afford a thoughtful, moralising tone: But Benserade then adds another quatrain, speculating on the fox's mental processes; finally it admits that the grapes really were ripe but 'what cannot be had, you speak of badly'. One of La Fontaine's early illustrators was the artist Jean-Baptiste Oudry, who was also artistic director at both the Beauvais and the Gobelins tapestry works. In consequence of this a series based on La Fontaine's fables designed by Oudry was produced by them during the 1740s and included "The Fox and the Grapes". These stayed in production