Much wine -- exceptionally clear bottles left (6)
I believe the answer is:
cellar
'much wine' is the definition.
'exceptionally clear bottles left' is the wordplay.
'exceptionally' indicates anagramming the letters.
'bottles' means one lot of letters goes inside another ('bottle' can mean to contain).
'left' becomes 'l' (common abbreviation).
'clear' anagrammed gives 'celar'.
'celar' placed around 'l' is 'CELLAR'.
(Other definitions for cellar that I've seen before include "Storage space, for wine perhaps" , "Room below ground for storage" , "Bottom room where wine may be stored" , "Underground storeroom" , "Where provisions may be stored" .)