That which makes beer heady? (5)
I believe the answer is:
froth
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for froth that I've seen before include "Mass of small bubbles" , "Lather" , "Small bubbles on a liquid" , "Spume or foam" , "Effervesce" .)