Originally, sherry within reach, drink! (6)
I believe the answer is:
shandy
'drink' is the definition.
(I know that Shandy is a type of mixed drink)
'originally sherry within reach' is the wordplay.
'originally' suggests taking the first letters.
'within reach' becomes 'handy' (I've seen this in another clue).
The first letter of 'sherry' is 's'.
's'+'handy'='SHANDY'
(Other definitions for shandy that I've seen before include "Drink of ale and lemonade 96)" , "A misture of ale and lemonade" , "Beer/lemonade drink" , "Alcohol" , "Drink made of beer and lemonade" .)