A quick question about (mexican) pozole...help!!!?

okay so I made some delicious homemade (Mexican) pozole from scratch on Sunday morning and it came out really good, perfect seasoning and spice and everything, so I invited my family to come over and have some on Monday night and when I heated the whole pot to a boil and served everyone it tasted kinda funny. Like it had a weird after taste and I felt so bad that I was braging about how good it was and then when they come to taste it it tasted really funny, so I'm trying to figure out what happened, what I think happened was I left it in the big silver tin pot( which I think is alluminum) for the whole day and night and also I put it away in the fridge when the whole soup was still warm and I know I should have waited till it cooled down but I was leaving and didn't want to leave it out too long so if anyone has had this happen to them with any kind of stew/soup please any input would really help that way I won't make that mistake again...thanks ahead for your help!!!