Lees

Lees are what settles. After Wine fermentation, yeast cells and fine grape solids drop. Gross lees are the first, gritty pile; fine lees are the later, creamier dust. Stirring fine lees (bâtonnage) is a texture choice in some whites: more body, sometimes a yeasty or nutty note. Leaving a red on dirty gross lees is how you pick up sulfur off-odors — a quality failure, not “complexity.”

This is not cheese whey. Whey is a protein liquid you drain. Lees are a yeast sediment you may keep in contact with wine.

Aging chemistry still belongs to phenolics #

Smith and colleagues describe tannin continuing to change after fermentation — with fermentation products and acids, and with a trickle of oxygen in barrel ¹. Lees are one of those fermentation products in bulk. They can bind some phenolics and change mouthfeel. They are not a substitute for grape tannin from skins. See Tannin and Aging wine.

An AVA does not require lees aging ². Stainless, full and cold, with lees racked off, is a freshness choice. Barrel on fine lees is a different oxygen-and-yeast conversation.

What to notice #

Look: a pale, fine layer versus chunky grape debris. Smell: bread dough and nut can be healthy fine-lees contact; rotten-egg is reduction, a different problem. Taste with Tasting wine: creamier mid-palate versus a bitter yeast bite from too long on dirty lees.

Must became this sediment. Grape solids that never dissolved are part of it. Return to Wine.