I am wondering why, with all of the many experiments done to investigate this, none of them were done with ice cream:
"Mpemba opted to skip waiting for his boiled-milk-and-sugar concoction to cool to room temperature like the other students had done. An hour and a half later, his mixture had frozen into ice cream, whereas those of his more patient classmates remained a thick liquid slurry..."
Boiled milk and sugar is not going to freeze in the same way as pure water, there are effects from the mixing of anything, but some of the substances in milk are oily so you might even have colloidal effects. It seems like if that's where Mpemba first saw it, you should start there to attempt to reproduce it?
"Mpemba opted to skip waiting for his boiled-milk-and-sugar concoction to cool to room temperature like the other students had done. An hour and a half later, his mixture had frozen into ice cream, whereas those of his more patient classmates remained a thick liquid slurry..."
Boiled milk and sugar is not going to freeze in the same way as pure water, there are effects from the mixing of anything, but some of the substances in milk are oily so you might even have colloidal effects. It seems like if that's where Mpemba first saw it, you should start there to attempt to reproduce it?