‘‘They used to get a cock (ie a male chicken), stick it in a sack and bash it against walls until it was completely pulverised. It was important that the bones were shattered and the whole thing was a bloody pulp. Then they’d chuck in a load of spices, such as cloves and mace, and drop the bag into a vat of ale while it was fermenting, and age the resulting brew for longer than normal to produce a much richer, heartier beer than normal.’’

Pete Brown explaining what cock ale was
from A Man Walks into a Bar
Pan Macmillan