Mixture of ethanol is in a drop of the hard stuff? (9)
I believe the answer is:
hailstone
'a drop of the hard stuff?' is the definition.
(I've seen this before)
'mixture of ethanol is' is the wordplay.
'mixture of' indicates anagramming the letters (I've seen this in other clues).
'ethanol'+'is'='ethanolis'
'ethanolis' anagrammed gives 'HAILSTONE'.
'in' is the link.
(Other definitions for hailstone that I've seen before include "bit of a storm" , "one in the shower" , "sign of cold weather" , "Hard precipitation" , "Frozen pellet" .)