Phenolic content in wine - quercetin. Like other flavonoids, the concentration of flavonols in the grape berries increases as they are exposed to sunlight. Some viticulturalists will use measurement of flavonols such as quercetin as an indication of a vineyard's sun exposure and the effectiveness of canopy management techniques. Anthocyanins are phenolic compounds found throughout the plant kingdom, being frequently responsible for the blue to red colors found in flowers, fruits and leaves. In wine grapes, they develop during the stage of "veraison" when the skin of red wine grapes changes color from green to red to black. As the sugars in the grape
History of the wine press from olives. This press would entail laying the grapes out underneath several planks of wood and then weighing the planks down with rocks to press the juice out from the grapes. The wine made from these rudimentary pressing wasn't held in high esteem by the Greeks, often tainted with impurities and having a short shelf life. Much more prized was the wine produced from "free run" juice that was released by the grapes under their own weight before any treading or pressing. This wine was believed to be the most pure and was often used for medicinal purposes. In the