Whiskey, port and bitter called for (3)
I believe the answer is:
rye
'whiskey' is the definition.
(rye whiskey is a type of whiskey)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rye that I've seen before include "One of Cinque Ports" , "Hard liquor" , "Burns's body came through" , "Wheat-like cereal plant" , "East Sussex resort" .)