Above: Alicia examines a bottle of Lini classic method wine “aging on its lees.” As she holds it up to the light, you can see the “lees,” the sediment, in the bottom of the bottle.

What is “lees aging”? And why is it important in the production of sparkling wine?

You often hear wine trade professionals talk about this phase, a very particular one, in the sparkling winemaking process but few can really tell you what it means and why it’s a fundamental element in sparkling wine production.

Sparkling wine is always produced by fermenting the wine twice, the second time in a pressurized environment (either a tank or in the case of classic method wines, in bottles).

After the second fermentation of the wine, the wine is aged “on its lees.” Lees are the sediment (the solids) produced as a byproduct of fermentation. They are made up mostly of dead yeast cells (fermentation is the process of yeast converting sugar into alcohol) and cells from the grape must.

It’s during the period of lees aging that the wine develops a lot of its flavors and texture. In general, the longer the wine is aged on its lees, the better.