Hydrogen sulfide and related sulfur compounds produced internally by yeast during fermentation are considered highly undesirable if they are excreted and exceed threshold concentrations in the finished wine, as they cause an unpleasant "reduced character". The threshold for hydrogen sulfide is on the order of parts per billion and that...
The objectives of this research are to monitor tannin and anthocyanin changes during berry development and over several growing seasons to understand how the vintage effects wine composition. Specifically, the objectives of this research project are :
· Determine the effect of berry development on the composition of phenolics (tannins...
The objectives of this research project are to understand tannin and anthocyanin changes during berry development in Pinot noir fruit and wines. Specifically, the objectives of this research project are:
· Determine the effect of berry development on the composition of tannins in cv. Pinot noir berries
· Determine the...
The objectives of this research project are to gain a better understanding of juice/must nutrition and the production of hydrogen sulfide and other 'off' sulfide odors in Oregon wines in relationship to both viticulture and winemaking practices. Specifically, the objectives of this research project are: · To analyze commercial juices/musts...
Little is known about the impact of temperature on proanthocyanidin (PA) accumulation in grape skins, despite its
significance in berry composition and wine quality. Field-grown grapes (cv. Merlot) were cooled during the day or
heated at night by +/–8 C, from fruit set to veraison in three seasons, to determine...
Rubus seed has a deep double dormancy that restricts germination due to seed coat structure and chemical composition. Improved germination of diverse Rubus species required for breeding improved blackberry and raspberry cultivars is partly dependent on the seed coat structure. This study evaluated the seed coat structure of three species...
Temperatures during the day and night are known to influence grape berry metabolism and resulting composition. In this study, the flavonoid composition of field-grown Vitis vinifera L. cv. Merlot berries was investigated as a function of diurnal temperature range (DTR). The DTR was compressed by cooling berries during the day...