I was taking a 3l of milk to work and leaving it there so I can mix my shake, until everyone else wanted to help themselves to my milk for their coffee, all work has is long life powdery crap.
So now I make up my shaker before i go to work, shaker holds about 700ml, so i make a double batch, 600ml milk, 4 scoups protein powder, and 4 tablespoons of milo. It actually ends up mixed much nicer, and tastes better after it has been in the fridge for many hours. Just ensure it stays cold.