I've got advent microwave and cold water and use them both although lately i use the cold water one more. I used to take my bottles out of the microwave one and put them together didn't used to make up bottles and used to use them for upto 24 hours, How can they become sterile if they're closed? Abi is fine never had any problems i just do what i think is right s there's to much of you should do this and not that these days.
Manda x
Manda x