Aging on lees plays a crucial role in developing wine aromas. Lees are the dead yeast cells, grape skin particles, and other sediment that settle at the bottom of the fermentation vessel. When wine is aged on lees, it allows for a process known as autolysis to occur, which has a significant impact on the aroma profile of the wine.
Autolysis and Aroma Development
During autolysis, the dead yeast cells break down and release compounds that interact with the wine, enhancing its aromatic complexity. This process can take anywhere from a few months to several years, depending on the style of wine being produced. Here are some key ways in which aging on lees influences wine aromas:
- Enhanced Yeast Aromas: Aging on lees can lead to the development of aromas such as bread, brioche, and pastry, which are characteristic of yeast. These aromas can add layers of complexity to the wine.
- Increased Nutty Notes: Autolysis can also contribute to nutty aromas, such as almond or hazelnut, which can further enrich the sensory experience of the wine.
- Buttery and Creamy Aromas: Lees aging can result in the formation of diacetyl, a compound that imparts buttery or creamy aromas to the wine, adding a luxurious texture.
- Enhanced Fruit Expression: While autolysis introduces its own set of aromas, it can also help to enhance the expression of fruit aromas in the wine, creating a harmonious balance.
- Complexity and Depth: Overall, aging on lees contributes to a greater complexity and depth of aromas in the wine, making it more interesting and enjoyable to drink.
Timing and Techniques
The timing and techniques of aging on lees can also impact the development of wine aromas. Winemakers have a variety of options when it comes to lees aging, each of which can influence the final aroma profile of the wine:
- Sur Lie Aging: This traditional method involves leaving the wine in contact with the lees for an extended period, sometimes several months or even years. This allows for maximum flavor extraction and aroma development.
- Regular Stirring: Some winemakers opt to stir the lees (a technique known as batonnage) during aging to increase contact with the wine. This can intensify the autolytic character and enhance aromas.
- Partial Lees Aging: In some cases, winemakers may choose to age the wine on lees for a shorter period or only use a portion of the lees. This can result in a more subtle influence on the wine’s aromas.
- Malolactic Fermentation: Combining lees aging with malolactic fermentation can further enhance the buttery and creamy aromas in the wine, creating a rich and velvety mouthfeel.
Effect of Grape Variety and Terroir
The impact of aging on lees on wine aromas can also be influenced by the grape variety and terroir of the vineyard. Different grape varieties have varying levels of compounds that can interact with the lees during aging, leading to distinct aroma profiles. Additionally, the unique environmental factors of a vineyard, such as soil type, climate, and altitude, can further shape the development of aromas in the wine.
Case Studies
Several wine regions around the world are known for their use of lees aging to enhance aroma development. Here are a few notable examples:
- Champagne, France: Champagne producers often age their sparkling wines on lees for an extended period, sometimes several years, to develop complex aromas of toast, brioche, and nuts.
- Albariño, Spain: Some producers in the Rías Baixas region age their Albariño wines on lees to enhance the fruity and floral aromas, creating a more aromatic and expressive wine.
- Chardonnay, California: California Chardonnay producers frequently use lees aging to create wines with rich buttery aromas and a creamy texture, showcasing the influence of autolysis.