The phenomena of potatoes that won't cook has happened to me a few times now over the years, yesterday, it happened in a beef stew I was making for 50, I had started cooking it the night before, then refrigerated it till morning then started it cooking again, planning for another three hour of slow cooking. They never cooked. I thought perhaps there wasn't enough liquids and added hot water, that seemed to help, but when they had been simmering in the stew for a period of 6 hours, I gave up and took them out of the stew to serve it, thankfully, it was delicious without them.
But what is up with this?
There has to be some food science behind this.