Rot Gut

I'll take all the guts from a rotten old stiff
and choose what I want with a taste or a whiff
pack them in jars and infuse them with yeast
to brew up a batch for the next midnight feast
my skill as a brewer has never been met
severed head '87 is my best vintage yet
we drink till we're knackered on putrefied pus
a chaser of lymph really gives me a rush