Sending milk to school for snack drink

[Redwood]

can anyone tell me how long they think milk will keep in a sports style drinking bottle? Ds loves it but am reluctant to pay extra for school milk as cots more and his sports bottle holds more.
I was thinking of putting a few ice cubes in to help it chill until break time.

Even here in Australia milk is fine for hours and hours (except on the very hottest of days). Also, it freezes so you could freeze a little the night before (in the bottle) and top it up with fresh milk in the morning so that the frozen stuff melts into the fresh without watering it down as ice would?

Put it in a thermos flask. They work to keep things cool as well as hot! :)

Might just be me but room-temperature milk is horrible. Cold or warm, please! Ice cubes would just water it down I think?

Or you can buy little thermos type insulating "jackets" to put around normal bottles if that is the only one he's allowed.

Washing the bottle might be interesting, though, unless it either goes in the dishwasher or it has a top wide enough to get a sponge down... If you don't want to (or can't) freeze the bottle, you could make ice cubes out of milk...

Milky ice cubes. Brilliant! Stealing that...

Great thanks, love the idea of part freezing the milk, and the ice cubes!

Frozen milk does tend to separate though, and if it's only part thawed it tastes watery because the fat takes longer to defrost.