Lovin' Spoonful.

C6H12O6 is the simple fructose molecule. Adenosine triphosphate (ATP), transports chemical energy derived from photosynthesis within the cells of grape leaves and converts it into sugar.
Today, we tested the sugar in our Syrah grapes for the first time this year. Using a hand-held optical instrument called a refractometer that measures the percentage of soluble solids in plant juice, we measured the grape sugar content in a random sample taken out in the vineyard. We got a reading of 21.8 °Brix. °Brix (°B) is a scale that is used to measure the percentage of sugar in grape juice.
Many growers still rely on sugar readings to decide when their grapes are ripe. However, sugar readings are only one indicator of grape maturity. There are other qualitative and quantitative evaluations that can best predict the optimal time of harvest. Amongst these are; the softening of the berries, the detachment of skin from pulp, brown seeds and stems, the analysis of pH and titratable acidity (TA).  Oh, and taste. Under-ripe, herbaceous flavours are personae non grata in Vinoland, but a °B reading of 24.5 or better is always welcome.
C6H12O6, the inclusion of which in grape juice makes a finished wine so appealing...and the exclusion of which in diet drinks makes Diet Coca-Cola so unappealing.