It is generally acknowledged that oxygen can have both a positive and a negative impact on a wine's chemical composition and sensory attributes. During the production process, from the initial harvesting of grapes to maturation in bottle, there are numerous points at which oxygen can be introduced, either inadvertently or intentionally. The impact of oxygen on fermentative performance, as well as during maturation, has been the subject of extensive research, both during winery operations and in the final package. Recent studies have highlighted the impact of oxygen on wine chemistry during early parts of the winemaking process. This review will discuss the effect of oxygen introduction at various points, from harvest to completion of fermentation, of wine chemical composition. In reviewing the opportunities to modulate wine chemistry and stylistic outcomes through the control of oxygen exposure, the review will highlight critical knowledge gaps in the underlying science behind some processes that are common within the wine industry.