For how long can we keep made formula milk in the bottle? If my baby has drank half milk for how long can i use it again??

A. In Another 30 to 40 minutes you will have to consume it otherwise you’ll have to discarded because the milk starts to get spoiled after that which is why you should always try to make the amount which the your child is going to have otherwise it all goes far away so maximum 40 minutes you can give me that after that