Why ‘shake’ a bottle of milk to mix when you can stir it, (not with a spoon of course).
The water temperature is still as to the level on the guidelines so ‘shaking’ or stirring won’t make a difference except on the amount of air bubbles that are created.
In the beginning we would follow every little word on the milk carton and what we were told by the midwives. The interpretation of the ‘mix well’ was to shake the bottle. But then we noticed the amount of bubbles in the bottles, even the anti-colic ones. We decided to adapt by stirring and the result: same as above but hardly any air bubbles. Voila!
Try it out and see… Easy peasy milk chemistry.