There was a relevant conversation on HN about this over a year ago that you might be interested in: How do people learn to cook a poisonous plant safely? http

There was a relevant conversation on HN about this over a year ago that you might be interested in: How do people learn to cook a poisonous plant safely? https://www.bbc.com/news/business-48859333 https://www.bbc.com/news/business-48859333 https://news.ycombinator.com/item?id=20874912 https://news.ycombinator.com/item?id=20874912 Bottom line, it is trial and error, an evolution of ideas and culture over many generations.