Ale and wine put before the queen (6)
I believe the answer is:
porter
'ale' is the definition.
(I know that porter is a type of ale)
'wine put before the queen' is the wordplay.
I cannot quite see how this works, but
'wine' could be 'port' (port wine is a kind of wine) and 'port' is found within the answer.
'queen' could be 'er' (abbreviation for Elizabeth Regina) and 'er' is present in the answer.
No letters remain.
This explanation may well be incorrect...
'and' acts as a link.
Can you help me to learn more?
(Other definitions for porter that I've seen before include "Hotel luggage carrier" , "Bitter beer - luggage carrier" , "Black beer or hotel employee" , "Hospital worker; beer" , "Bag carrier in hotel or railway station" .)