Post-fermentation treatments may begin almost immediately after fermentation. These may involve any necessary adjustments to the wine’s physicochemical composition, as well as procedures such as sur lies maturation. Subsequent modifications involve various forms of clarification and fining, and chemical and biologic stabilization (including oxidation control). Both before and after bottling, further spontaneous chemical changes occur (aging). These affect the wine’s visual, gustatory, and olfactory attributes, with potential beneficial or detrimental consequences. These changes may occur in either inert or wood containers. Because of the significance of maturing premium wines in barrels before bottling, the taxonomy, distribution, and structural and chemical attributes of oak are noted, as well as barrel construction, conditioning, and care, as well as their alternatives. The origin and chemical and physical attributes of cork are explored, as well as stopper production, insertion, faults, and sorting, plus closure alternatives. The properties and production of various storage/transport containers (notably glass) are subsequently described. A discussion of wine spoilage follows including: cork-related problems; the various forms of microbial spoilage; sulfur and other off-odor development and control; and accidental contamination. An examination of winery waste water and treatment completes the chapter.