Old wines are those wines whose aging potential is well documented and well known by both producers and connoisseurs. Not all wines age well, this is influenced by several factors, including grape variety, vintage, viticultural practices, wine region or winemaking style. The way the wine is stored after bottling can also influence its aging potential and may require significant time and investment. As for red wines, a high level of aromatic compounds, such as phenols (especially tannins), will increase the likelihood that a wine will have a favorable aging potential.

Wines with a high level of phenols include grape varietals such as Cabernet Sauvignon, Nebbiolo and Syrah. In general, wines with a low pH, such as Pinot Noir and Sangiovese have an increased aging potential. White wines with the best aging potential tend to be those with a high acidity and fruit concentration. The high acidity in white wines acts as a preservative and has a role similar to that of tannins in red wines. White wines have a significantly reduced amount of phenols (although fermentation in oak barrels favors the creation of phenolic compounds) due to the wine making process that includes little or no contact with the skin of the grapes.