How long do Empty sterilised bottles last for when you are out and about?

[Kaoru35]

Hi,
I was wondering how long do Empty sterilised bottles last for when you are out and about? (eg shopping or going for walks etc). I wash them then put them in the Milton steriliser before hand and they would be put in the changing bag I have while I'm out. Also I would be using the pre made formula bottles to pour into them.

Thanks

Once sterilised, put the lid on and keep them closed and then they’ll remain sterilised for 24 hours.

Well, all day- it’s not something I’d worry about.

Thanks :)