HF: So where does demonic possession come into play?

SL: So in the medieval era, particularly between about 1300 to about 1600, this disease [ergotism], which we now know as food poisoning, was thought of as demonic possession. People would go to monasteries to be treated, where they most likely got better because they weren't eating rye bread while they were in the monastery. In terms of the Salem Witch Trials, there are several well-researched papers that have put forward this theory that—although there were probably other aspects to the Salem Witch Trials too, like thrill-seeking and politics—there was mass-hysteria that some theorize were prompted by ergotism. It's a disease that women, and particularly young women, are the most susceptible to. The fact that the accusers were all teenage girls makes sense along with the disease.

Also, ergot thrives in wet, cold years, which 1691 and 1692, the years the witch trials happened, were. There's a lot of other things that back up that evidence. And basically these scholars are saying that these nine young women—and then eventually some adult women and men—were actually afflicted by something. And much like the European Witch Trials, the last of which was only 50 years before the Salem Witch Trials, the reason they were able to find for their illnesses was witchcraft because they didn't have a better explanation for what was happening. From there, people that were afflicted began accusing people they didn't like or people that were outsiders in town of being witches who gave them these afflictions. So it's a really interesting body of research.

HF: Is ergotism still a danger to the public?

SL: Currently no, because ergot kernels are really obvious when you look at pictures of them. They're usually larger than the grains they infect and they're black. But they were so common in rye that, until the 17th Century, they were even included in botanical drawings of the rye plant because people thought they were a part of rye. That's how common they were. People didn't see them as a fungal infection. After they figured out that this was a dangerous fungus, they started separating them out for the rye grains, and that solved a lot of the problems. Today, we not only do that within processing, but we also use anti-fungal too, so that would prevent the distribution of the ergot spores that cause the ergot growth. They are in some ways a little bit like... Have you ever seen huitlacoche, the fungus that grows on ears of corn? It's kind of like that, but huitlacoche is a delicious delicacy and tastes like corn and mushrooms. Ergot kills you. So that's a pretty big difference.

HF: And there's a taqueria in Hell's Kitchen where you can order huitlacoche.

SL: Yeah, American farmers still see huitlacoche as a waste, but there's someone, I think Sean Brock, who is trying to create a culture around it like in Mexico, where huitlacoche is prized because it's worth three to five times a regular ear of corn. It's similar to ergot in that it's a fungus that's growing in place of a kernel. But part of the reason ergot is confused with rye is because ergot actually has a purplish-red color, especially when it's ground, so bread that's made from flour with ergot in it looks similar to rye, which is a very dark grain that creates very dark-hued bread such as pumpernickel. So it's difficult to detect the ergot from the color of the bread.