Matilda was on the Ha-AR formula and we used the water at just above room temp. I would store the bottles in the fridge & when it was time to use them I would heat up the water & add the formula just on giving it to her. So the bottles would have 180mls cooled boiled water in the fridge once sterilised and then I would take them out of the fridge, pop the bottle in the microwave for 20 seconds to take the coolness off them & then add the formula & give it to her straight away.

I found leaving the formula at any temp made it go more thick... so I just decided to make them up as we went. It worked really well for us doing it that way. I often tried to mix up bottles ahead of time but found it just got too thick for us, but maybe we were making them up too warm to start with.