Hunter Valley wine rot), "Greeneria uvicola" (bitter rot) and other fungi from the genera of "Aspergillus, Penicillium" and "Alternaria". Susceptibility of certain wine grape varieties were found to increase as the grapes reached higher Brix sugar levels. Further research in the 2000s, showed that some of the open canopy techniques used to prevent "Botrytis" grey rot may actually promote the development of some of these other types of rot. Ripe rot, in particular, seemed to thrive at the higher ultraviolet B (280–320 nm) light exposure that open canopies allow. To compound the potential problem for Hunter Valley wine growers is that, as of
Phenolic content in wine Average total polyphenol content measured by the Folin method is 216 mg/100 ml for red wine and 32 mg/100 ml for white wine. The content of phenols in rosé wine (82 mg/100 ml) is intermediate between that in red and white wines. In winemaking, the process of maceration or "skin contact" is used to increase the concentration of phenols in wine. Phenolic acids are found in the pulp or juice of the wine and can be commonly found in white wines which usually do not go through a maceration period. The process of oak aging can also introduce phenolic compounds