How long is it ok to have formula sitting around in bottle?

[Pootles2010]

Trying to get ds to take bottle, after 6 months on breast, just one bottle in afternoon, to get him ready for nursery.

If i make him bottle up, and he tries but refuses it, how long before i have to chuck it? Is it straight away, or can i keep it in bottle for hour or so? Thanks!

it should say on the box - I think 2 hours is the maximum time before throwing it away

two hours, but it will have a longer life i believe if you keep it in the fridge. But then he'll have to like it cold, as heating and cooling repeatedly is pretty dodgy.