If I have already warmed up the breastmilk, and baby does not complete drinking it, how long can i keep it in the open for? Can I refrigerate after?

I threw away all the unfinished breastmilk 5 mins after it was left untouched. I rather waste milk than get my baby to have runs later. At times, I will force my hub to drink the leftover milk coz supposed to be gd.. hehe.... but most of the times, I will just discard it.