Jamieson, Fausset and Brown on Jeremiah 48:11

11. settled on ... lees--(See on Is 25:6; Zep 1:12). As wine left to settle on its own lees retains its flavor and strength (which it would lose by being poured from one vessel into another), so Moab, owing to its never having been dislodged from its settlements, retains its pride of strength unimpaired.

emptied from vessel, &c.--To make it fit for use, it used to be filtered from vessel to vessel.

scent--retaining the image: the bouquet or perfume of the wine.