Glass baby bottles are once again becoming a popular way to feed your infant. Kimberly Rider, author of "Organic Baby: Simple Steps for Healthy Living," recommends glass baby bottles as a safe way to serve warmed breast milk or formula as long as they are cleaned properly. You must always sterilize glass baby bottles before the first use and every use thereafter, or as often as your baby's health care provider recommends.
Fill a large pot with water and place the bottles in the pot. Make sure the pot is large enough to hold all of the bottles you wish to sterilize, and ensure that there is enough water to cover the bottles completely. Use care to prevent the bottles from hitting each other too hard, causing cracks or breaks that will pose a safety hazard.
Bring the water to a rolling boil. Allow the bottles to boil for approximately five minutes to kill germs and eliminate bacteria.
Remove the bottles from the boiling water using the tongs. Even outside of the water, the bottles will be quite hot. Place them on a dry kitchen towel or a specially designed bottle drying rack to drip dry.
Let the bottles remain on the towel or drying rack until they are completely dry. It will be easier to mix formula in them if there are no water droplets.
Instead of sterilizing on the stove top, you can place the bottles in the dishwasher and run it on the sterilizing cycle.
Avoid boiling the bottles for an extended amount of time because this could cause cracks or breakage, say Duyff and the American Dietetic Association. Allow the bottles to cool completely before running cold water on them or in them because this could also cause cracking.