Wine left to breathe in protective cover (6)

'wine' is the definition.
(type of wine)

'left to breathe in protective cover' is the wordplay.
'left' becomes 'L' (common abbreviation).
'to breathe' becomes 'be' (breathe can mean to be or exist).
'in' means one lot of letters goes inside another.
'protective cover' becomes 'mac' (macintosh raincoat).
'l'+'be'='lbe'
'lbe' inserted inside 'mac' is 'MALBEC'.