Possible Clues:

• Mouldy
• Old-fashioned, like unfermented grape juice?
• Affected by mold or mildew
• Needing airing
• Needing an airing-out
• Not fresh, but has to stay at the end
• Like old attics
• Needing an airing
• Like many a summer cabin after a long winter
• Mouldy-smelling