The redox processes are an unavoidable and very complex part of winemaking. The chapter examines the main redox processes that take place during grape subsequent technological processes, maturation, and aging of wine. Some of them lead to the ennobling of wines and their stabilization, while others cause the alteration, and degradation of wines, and the appearance of numerous defects of wines. The consecutive, parallel, and spontaneous development of multiple redox processes, and their dependence on pedoclimatic, agro-technical, and technological conditions influence the structure, appearance, aroma/bouquet, taste, and stability of wines. The knowledge of the production mechanisms, the influencing factors, of the particularities allows the realization of precision vinification, characterized by the reduction of the additive and subtractive technological interventions, of the quantities of adjuvants, and the production of ecological wines. Monitoring redox processes during alcoholic fermentation through oxygen management is essential for the quality of wines.