Have to make formula up with cooled boiled water. Currently making in sterilised glass storage bottles and then pouring into the bottle when making up formula. But would be useful to store the water in the bottle but I don’t want the test exposed to water for that long so looking for a different lid to store and transport. Like the little discs that sit over the opening but not ones that are from a random Amazon shop but a shop that will have passed testing for baby safe stuff. If that makes any sense?