Powder, Concentrate & Ready-to-Feed
Infant formulas generally come as ready-to-feed liquid, concentrated liquid, and powder. Which type is going to work best for you is likely to depend on how much formula you plan to use, where you plan to use it, and how much you want to spend.
Formula Prep by Form:
PowderThe simple concept here is that you add powder to premeasured water and shake a lot. It is certainly your most economical choice, and quite frankly works perfectly well for most babies. You can decide whether to mix it up as you go or prepare a full day’s worth at a time and refrigerate it.
Liquid concentrateThis is the “just add water as directed and shake” formula option. Mixing and measuring is again quite straightforward, because all brands of concentrate call for equal amounts of water and concentrate. While some parents find concentrate to be easier, neater, and/or more convenient than powder, it is a convenience for which you will pay more.
Ready-to-feedThis is your no-mixing, no-measuring, no-mess option. The use of ready-to-feed formula is hopefully self-explanatory—what you see is what you give. While the fairly small “Ready-to-Feed” caption isn’t always prominently displayed on the label, you’d be hard pressed to miss the distinguishing price tag. While buying ready-to-feed formula inevitably costs the most, it leaves almost no room for error (assuming that you don’t mistake it for concentrate and dilute it with water). It also happens to be the easiest way to limit your newborn’s exposure to too much fluoride. Unopened cans can be conveniently stored at room temperature. Once opened, unused portions can be covered and then refrigerated for up to 48 hours.
Source Heading Home With Your Newborn, 2nd Edition (Copyright © 2010 American Academy of Pediatrics)