Manufacturers of Playtex Drop-Ins bottle liners stress their bottle system's similarities to breastfeeding, as well as the convenience and cleanliness of the drop-in plastic liners. While the plastic liners may be easy to use, you may wonder how to warm the formula before feeding your baby. You can warm up the formula in several ways, if you prefer giving your baby warm formula, which isn't really necessary.
After you pour the unheated formula into the Playtex Drop-Ins liner, warm up the formula by placing the bottle in a container of warm, but not hot, water. Loosen or remove the cap while heating the formula. The formula should heat up very quickly, within a few minutes. Simply mixing sterile water with formula and pouring it into the liners, then running them under warm tap water also warms up the formula.
You can't warm the bottle in the microwave once you add the formula to the liner. Formula may not heat evenly in the microwave, which means the liquid could have hot spots that you might not feel from the outside the bottle, but which could burn your baby's mouth and gastrointestinal tract. You can, however, warm up water in the microwave, let it cool slightly and then add it to the bottle.
Boiling Tap Water
If you feel comfortable using your tap water to make formula, simply mix the powder with warm water. Boil the water first to kill any microorganisms. Then let it cool to lukewarm temperature before mixing it with the formula. The American Dietetic Association states that adding hot water directly to formula powder could affect the stability of nutrients in the formula. Let the hot water cool for at least 15 minutes at room temperature before pouring it into the liner and feeding to the baby, Playtex suggests.
Contrary to popular belief, it's not necessary to warm up formula water. Simply pour the formula made with sterile water at room temperature right into the liner. Breast milk doesn't come out hot, and formula doesn't have to be either.