A gross idea.

A long time ago, strong english ale used to be leinted. A leint ale was produced by adding human urine, and was then called strong or bitter ale.

I kid thee not.

Contrast the German Reinheitsgebot, which disallowed stuff like urine in beer.

The word "leint" is an English verb dating backing to the mid-17^th century. It's derived from another old English word, "lant", meaning "urine" and, as far as I can tell, was only used in association with the practise of adding urine to beer to strengthen it, ("to leint ale").

This explains the follow drink-related idioms:

"(going out) on the piss" : A night on the town with the express aim of getting drunk
"pissed" or "pissed up"   : state of being drunk
"a piss-up"               : A drinking session
"a piss-up in a brewery"  : An easy-to-organise drinking session