GB. England. Oxford. Lincoln College. Poisoned Ivy Beer. On Ascension Day students from Brasenose are invited to visit Lincoln College and take a free glass of beer. However to discourage too much indulgence, the beer is ‘poisoned’ with ivy, thus making the beer somewhat unpleasant to drink. This is a long-standing tradition between the two colleges and is said to be a penance either for a Lincoln man killing a Brasenose man in a duel, or for the murder of a Brasenose man by a town mob at the gates of Lincoln because the students there refused to open up and give him safety. 2015.