Definition - What does Bottle-Aged mean?
During fermentation, wines can be bulk-aged or bottle-aged, and they have gone through both processes at some point even though one form of aging can be emphasized over the other. Bottle-aging which occurs after primary fermentation is complete. It can take as little as three weeks or as long as the wine or drinker prefers. Dry wines or still wines that are made into sparkling wines are usually bottle-aged, allowing for more control over carbon dioxide and sugar exposure.
WineFrog explains Bottle-Aged
Aging a wine in the bottle is faster than aging it in bulk, and the maker has greater control over the chemical adjustments within a bottle amount than a large quantity. Bottle-aging is a reductive aging practice that begins as soon as the wine is sealed in the bottle. The surface area exposed in the bottle is less than that of a barrel's or vat, it and allows for less oxygen to influence the taste of the wine.
Before bottle-aging, the wine must complete fermentation, have time for the sediments to calm down and have lost all natural carbon dioxide. The wine is also more sensitive to temperature changes in the bottle and can have a more uniform taste overall when bottle-aged. There are no restrictions of how long the wine should stay in the bottle, but keep in mind that it does age faster and produces negative effects quicker when bottle-aged.