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?

Personally, I used to throw away any unfinished milk an hour after I warmed it up. This is because bacteria thrives in warm room conditions and especially in a humid climate like Singapore, the amount of bacteria in the milk would increase as the time passes. These bacteria can cause upset stomachs so I rather "waste milk" then have my baby suffer. Do not refrigerate leftover milk for your baby's safety. What I did was to freeze my breastmilk (after pumping) in small batches of 120ml instead of 200ml and above. This way I can control the amount that I warm up and would waste lesser this way.

Based on this article, there aren't really clear guidelines on "leftovers" and there are a lot of factors that go into whether or not leftover warmed milk is safe to reuse and for how long. http://kellymom.com/bf/pumpingmoms/milkstorage/reusing-expressedmilk/ There's always the smell test (if it smells like spoiled milk, throw it out). Personally, I only let it sit in room temp or in an air-conditioned room for an hour. Hope this helps!

From what I understand, it is not recommended to reuse unfinished milk as it may be contaminate by bacteria after contact with your baby's mouth. Try putting a smaller amount into the bottle for each feeding If your baby consistently fails to finish the whole bottle. This will minimize wastage. If your baby want more, you can then prepare another bottle for her.

Maximum you can keep for an hour from the time you heat up the milk. Any leftover will have to be thrown away. Another way to know is by the smell. Weather also plays a very big role. If you put it openly in a hot and humid day, you may not even be able to wait till 1 hr. By then, high chance the milk will be spoilt already.

Breastmilk that are warmed up and baby's saliva had touched the milk, you can only keep it for 1 hour and cannot refrigerate it again. It will be better if you can warm in smaller amounts i.e. baby drinking amount. Also note that thawed frozen milk must be consume in 24 hours.

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.

One hour and then throw it away. It can't be put back in the fridge and reused.