Wine drinkers already know that wine is aged; but how exactly does wine actually age? The ability for wine to age is influenced by factors such as wine region, winemaking style and grape variety. As wine sits in a bottle or barrel, the colors, aromas and flavors change. Wines that age best have high levels of acidity and tannins.
- Chemistry – Wine is a combination of chemical compounds that interact and change with the environment and each other. Reactions between phenolic compounds, esters, alcohols, sugars and acids are intricate and modify the aromas in wine. When wine ages, the compounds react over time and create subtle, complex flavors.
- Esters – Esters contribute to the wine’s aroma and are created due to the reaction between the alcohol and acids within the wine. The kinds of esters produced during the process of esterification are determined by the type of yeast used during fermentation. Hydrogen encourages the reaction to take place. This complex reaction is considered a living, breathing organism that has the ability to constantly change. Wine that has been aged for about two years may have aromas of pear. While the same exact bottle of wine aged five years might develop and produce a buttery aroma.
- Phenolic Compounds – These compounds are chemicals responsible for the smells and tastes in all foods. For example, the compound aldehyde provides the taste of vanilla. There are a variety of phenolic compound types. However, tannins are the most important kind for wine where aging is concerned. As wine ages, the tannins gradually undergo polymerization, which is a reaction that binds them together, allowing them to fall to the bottom (this is also referred to as sediment). Then the aged wines begin to taste mellower because they lack their ability to bind with other compounds.
Aging wine is a science that is perfected by each winemaker. The art of aging wine is dependent on a variety of things. Each barrel or bottle of wine will age slightly differently from the next. Balance is essential to aging wine perfectly and involves a combination of fermentation flavors, fruit flavors and aging flavors. The conditions the wine is kept in or the bottle determines whether the wine needs to age for one year or longer. The process of aging wine is essential and well respected in the industry.