Back to the original topic... there was a cult in ancient Hellenistic culture based on the nature Goddess Persephone aka Demeter. One researcher named Joseph Campbell suggested that the holy beverage used in initiation rites into the sacred, secret society was ergot. This secret group of intellectuals was called the eleusinian mysteries.
http://users.erols.com/nbeach/eleusis.html
Personally I doubt it was ergot because although some fungus is good, the fungus that grows on rotton moldy bread can kill you and give you St. Anthony's Fire. Unless they had some way we don't know about to extract the active ergolines or render safe the poisonous parts of the rye mold (which is quite possible since it was a secret society and most of the documents from that time period that the writers WANTED people to know about are not accessible to us due to destruction by invaders, decomposing over the years, etc) it could not have been ergot that they ate. It's possible but I think very unlikely because you would have to eat a lot to get any effects.