Yeast strains used in wine production are known to differ in some fermentation characteristics, including rates of fermentation, alcohol tolerance, degree of foaming, temperature tolerances, volatile acid production, and hydrogen sulfide production. There may also be significant sensory differences in aroma and flavor in wines fermented with different yeast strains....
A study was undertaken in December of 1986 to evaluate Riesling wines made from clonal material from the 1985 and 1986 vintages grown at a cooperative plot at Champoeg Vineyard. The objective was to have a trained panel evaluate differences in aroma and flavor-by-mouth descriptors to determine:
1. The change...
Riesling, Chardonnay, and Pinot noir wines from the 1992 vintage were fermented with several different commercial yeast strains. Differences were observed in fermentation rates, wine composition, and aroma and flavor. Preliminary results were reported on in the OSU Wine Grape Research Progress Reports, 1992-1993, Special Report 929, June 1993, OSU...
Commercial fermentation practices have been evaluated for several vintages to determine their effects on anthocyanin and phenolic extraction, wine color intensity, color stability, and sensory characteristics of Oregon Pinot noir wines. Trials have included fermentation processing practices (1994), the use of different commercial yeast strains (1995 and 1996), the addition...
During the 1994, 1995, and 1996 vintages we designed a series of trials to evaluate the effects of commercial Pinot noir fermentation practices in Oregon on wine composition and quality. Differences have been observed in anthocyanin content, color intensity, polymeric pigment content, phenolic content, and in aroma, flavor, body, and...
Several macerating pectinase enzyme preparations are currently being used by Oregon wineries to enhance color, color stability and phenolic extraction of red wines. Previous research on the use of commercial pectinase enzymes in Oregon Pinot noir and Cabernet Sauvignon wines showed that some enzyme preparations were capable of reducing red...
Winemakers commonly attribute differences in color, color stability, and phenolic composition to different fermentation practices. The extraction of anthocyanin pigments and other phenolic compounds from the skins, pulp, seeds, and stems to a large degree determines the composition and quality of red wines.
During the 1994 vintage we designed a...
In 1981, a trial was established to evaluate the performance of several strains of malolactic bacteria. Pinot noir wines were inoculated with several strains of malolactic bacteria, and their performance was reported by Watson (above). One strain, ML-34, can be thought of as the industry standard, while ER-1A and EY-2D...
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...
OBJECTIVES:
To determine the effects of commercial enzyme and tannin additions on the appearance, aroma and flavor profiles of Pinot noir processing trials. The wines were made by Barney Watson as part of the experimental wine program at Oregon State University (see Fermentation Processing Effects of Anthocyanin and Phenolic Composition...