Bringing powdered formula on plane

We are taking on a plane for the first time next week. I will need to feed them and they take powdered formula. DH just got back from a work trip and he said the flight attendants wouldn't let a woman mix it herself? That they had to do it for her? Knowing DH he misunderstood.

Also, I want to bring it in the premeasured formula containers and buy water once we get through security. Then I was thinking how do they know it isn't coke or something? Do they make you taste it? Or do you have to bring like an unsealed can?

Re: Bringing powdered formula on plane

When we flew last year I already had the powder in the bottles then bought the water after security. We had no problems