A series of studies were undertaken to better characterize influences of viticultural and vinification decisions on wine quality parameters, including those that affect aging potential. Elemental sulfur (S0) is commonly used to control powdery mildew, a ubiquitous disease of grapevines. While beneficial over alternative control products in many respects, late season S0 applications increase the potential for undesirable "reduced" aroma development in wine produced from treated fruit, as residual S0 concentrations >1-10 [MICRO SIGN]/g increase H2S evolution during fermentation. However, the persistence of S0 in the vineyard and through vinification is poorly understood, partially owing to the limitations of previous methods for S0 analysis in media that contain other forms of sulfur. A simple, economical technique was developed to quantify S0 residues on grapes in the vineyard and throughout vinification. The technique is based upon complete conversion of S0 to H2S and the subsequent capture and quantification of that gas using commercially available detection tubes. This method was then utilized to analyze grape and must samples from 3 years of field trials, in which the variable factors were S0 formulation, dose, and application timing relative to harvest. Additionally, a series of investigations was undertaken to better understand the impact that increased H2S production during fermentation has on final wine chemistry. While formulation and application rate affected S0 iii residue concentration and persistence for some treatments, timing between final treatment and harvest consistently had an effect on final residue concentrations. Cessation of S0 application 35 days or more prior to harvest resulted in S0 levels below 10[MICRO SIGN]g/g for all treatments. For some treatments, harvest S0 residues below 10[MICRO SIGN]g/g were observed even when spraying was ceased as late as 22 days before harvest. In wine produced from the S0 field trials in which elevated H2S production was observed, there was also increased incidence of H2S formation in finished wines post bottling, even though no H2S was present at bottling. The H2S that re-emerged 3-weeks and 6-months post bottling correlated well with H2S produced during fermentation. H2S produced during fermentation also correlated well with a "latent" pool of H2S that was releasable by treating the wine with a reducing agent. In a separate experiment, the effects of the timing of light exposure on grape derived volatiles was explored. Fruiting zone leaf removal is a common practice to increase light exposure, which has been shown to reduce disease pressure and positively influence ripening. The compound TDN (1,1,6-trimethyl 1,2-dihydronaphthalene) has been linked to the classic "petrol-like" aroma found in some Riesling wines. Higher concentrations of TDN precursors in grapes has been associated with increased cluster sun exposure. A field trial was undertaken in which fruit zone leaf removal was applied at three different timings. Concentrations of carotenoids and bound and free TDN and other volatiles were quantified in harvested berries and in wines. Leaf removal at 33-days post-berry set significantly increased zeaxanthin in Riesling grapes mid-season, total TDN and vitispirane in the juice of mature Riesling grapes, and free and total TDN in finished wine, while earlier or later leaf removal had no effect. iv