Seems to me like a pretty unscientific way to conclude whether a food is edible (or good for you). But it makes sense of course, if you didn't have access to modern science due to poverty or era.

Even modern grain infrastructure relies on delcarations of chemical usage and not itemized testing. Real time testing equipment is prohibitively expensive and lab testing takes too long to do it before mixing a load of grain into a silo. On site tests are done but for indicators of moisture spoilage, protein deterioration and disease, but not chemical contaminants.

Haha reminds me of the time tintin mixed in an anti-alcohol drug into the picaros' meal, and they wouldn't eat it until snowy did.

There is such a drug, sort of: Disulfiram. Though the effect isn't technically to make alcohol taste foul, it's to make consuming it give an almost instant, terrible hangover.

Some inkcap mushrooms which are otherwise edible have a mycotoxin with the same effect, coprine. There are persistent rumours that other mushrooms can contain some of it too, not verified as far as I know but there's enough poorly understood variation in mushrooms that I wouldn't dismiss the possibility.

Haha one of my favourite scenes, apart from Captain Haddock losing his taste for whisky at the start!!!

Great read!

> One of the most oft-repeated stories about Frederick’s relationship with the potato concerns the ingenious tactic of reverse psychology the King embarked on to increase interest in potatoes: rebranding it as a ‘royal vegetable’. By ordering his soldiers to plant potatoes in royal fields and lightly guard the crops, allowing the locals to sneak in and pillage the vegetables – the Prussian king would conclude: what is worth guarding is also worth stealing.

This reminds me of Rory Sutherland's "Lessons from an ad man" where he tells this story, and then follows-up with another myth-like story about Ataturk wanting to modernize Turkey, but rather than ban head coverings for women, he required prostitutes to wear one.

full video (which is definitely worth a watch): https://youtu.be/audakxABYUc

3:20 is where the story starts: https://youtu.be/audakxABYUc?t=200

The story about lightly guarding potatoes seems to be common European trope, I've heard it in many countries. Variations include the one you mentioned, and one where potatoes were placed in a warehouse with increased security, in order to attract the attention of the peasants who were allowed to steal them.

I just came across the Frederick the Great story somewhere else this morning. That version also claimed he even told the guards to accept bribes from people trying to steal the potatoes.

That they could see that it was a plant in the nightshade family probably also didn't help matters.