What are lees?

• A. The CO2 in sparkling wine.
• B. The grape skins remaining after pressing.
• C. The sugar residual in wine.
• D. Dead yeast cells, a byproduct of fermentation. Can add nutty, biscuit component or rounder mouthfeel if wines are aged on the lees.

Answer: (D)

Lees are the sediment that forms in wine from dead yeast cells and other particulate matter after fermentation. This material settles to the bottom and can undergo autolysis, releasing compounds that add texture and flavor to the wine. Aging on the lees can give wines a nutty or biscuit nuance and a rounder mouthfeel, which is a desirable effect in many styles, especially whites like Chardonnay or some sparkling wines.

The other options aren’t lees: CO2 is a gas produced during fermentation, not sediment. Grape skins remaining after pressing are called pomace or skins, not lees. Sugar residual in wine is leftover sweetness, not sediment.