Small beer
Small beer is a
beer that contains very little
alcohol, perhaps less than one percent. Sometimes unfiltered and porridge-like, it was a favored drink in
Medieval Europe and colonial
North America. It was sometimes had with breakfast, as attested in
Benjamin Franklin's autobiography. Before public
sanitation, water-transmitted
diseases, such as
cholera, were a significant cause of death. Because alcohol is toxic to most water-borne pathogens, and because the process of brewing any beer from
malt involves boiling the water, which also kills them, drinking small beer instead of water was one way to escape infection.
Small beer is not made in any significant amount today, though a similar product called non-alcoholic beer (which actually has a little alcohol) is quite common.
Metaphorically, small beer means a trifle, a thing of little importance.