A few months back C's Brother, who has a very different brewing philosophy than I, brewed an ESB. After some discussion, it was obvious that the exactly meaning of the label 'ESB', (extra special bitter), was not particularly well understood by me. Further investigation lead me to a believe that ESB was a term applied to a bitter (or amber ale) that was stronger than normal. Not very helpful given the wide rang of options for what could be called a bitter.