I know the reference but just fyi, this was not nearly as common as claimed and not responsible for a lot of witch trial stuff. It was more like cops interrogating people until they freak out, then claim "fine I wrote my name in the devil's book, but Becky did too!!" And then it ended up some prosecutorial bullshit with them wanting a confession out of everyone.

The "funny" thing is, those that confessed and repented often survived and lived normal lives. It's more people that denied it and had others claim they were witches were executed.

And there are weird instances like a guy who confessed but was still executed... But he legitimately was giving divinations, and telling people how many children they would have. Like a back in the day psychic. The witch trial stuff really, really didn't like divination. Herbs and midwifery stuff was way less of a big deal, and an honored profession being a "physic". It was not considered witchcraft to use herbs to heal people unless you did weird rituals.

For grain to give you hallucinations, it has to be rye grain and in a cold and wet climate, which ergot specifically would grow in. Then the rye grain itself would grow big black visible horns, and they would still need to not discard that obvious contaminated grain and grind it into flour. Then that flour was eaten, and they hallucinated. And it fucked up your veins and gave you black limbs often too.

There's often not great evidence for this phenomenon unless they are in a cold and damp area growing rye, and report the medical issues on top, black limbs.

People act like if you let bread mold it'll grow it, but that's not the case. It's much more rare of a phenomenon, a fungus that attacks rye itself.