How to Sterilize Baby Bottles

Making Bottles Germ-Free for Your Little One

A new babies comes with lots of questions. How often do I need to change her diaper? How much should she eat? Do I have to sterilize her bottles after every use? Sterilizing is a method of killing germs on the bottles and other feeding items to keep those potentially dangerous microbes out of your little one's mouth and tummy.

Do You Have to Sterilize Bottles?

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Most experts agree that sterilizing bottles on a regular basis is no longer necessary because of relatively safe water sources. Thoroughly washing bottles and nipples in hot water with soap or in your dishwasher makes the bottles safe for your little one. Even if you sterilize the bottles, they don't stay sterile very long. They eventually start picking up germs from your home.

The one exception is newly purchased bottles. You never know what bottles and nipples come into contact with during the manufacturing and shipping process. Sterilize new bottles and other items that go in your baby's mouth such as pacifiers and sippy cups. After that, you don't have to sterilize them unless it makes you feel better.

You may want to sterilize in certain situations, including:

  • Unreliable or potentially contaminated water supply
  • Premature baby
  • Babies under 3 months
  • Babies with weakened immune systems

Sterilizing Methods

Choose from one of these methods to sanitize the bottles before you fill them up for your baby:

  • Boiling: Pop bottles and other feeding items into a large pot of water. You may need to put something heavy on top of plastic bottles to keep them from floating. Bring the water to a boil. After five minutes, take the bottles out of the water.
  • Steam sterilizer: You can get an electric bottle sterilizer for easy sterilization. Follow the instructions for your sterilizer to ensure it works properly. Another option is a microwave steam sterilizer.
  • Dishwasher: If your dishwasher has a sanitizing setting or a hot water wash with a heated drying cycle, you can use it to get rid of germs. Put plastic bottles on the top rack, so they don't melt from the heat.

Cleaning vs. Sterilizing

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What's the difference between normal cleaning and sterilizing your baby bottles? Sterilizing uses hot temperatures to kill germs on the bottles. Steam and hot water are the two primary methods used for sterilizing.

Washing simply means your normal routine: using hot, soapy water or the dishwasher to remove the milk and other gunk from the bottle. These methods usually kill most germs, which is why sterilizing isn't necessary in most cases. You should wash your baby bottles after every use to get rid of the old milk and to prevent bacteria from growing.

Other Feeding Safety Tips

Feeding safety starts with clean bottles, but you can do other things to reduce the chances of germs getting into your baby's food.

  • Wash your hands before you handle your baby's bottles, nipples, expressed breast milk or formula. 
  • Wash the top of the formula container before using it for the first time.
  • Store breast milk properly in the refrigerator or freezer. Breast milk is usually safe in the back of the refrigerator for three to eight days and in the back of the freezer for up to six months.
  • Toss formula or breast milk that your baby doesn't finish at one feeding. Your baby's mouth can introduce bacteria into the bottle during feeding.
  • Mix formula powder with a safe water source. If you're not confident in your tap water, use bottled water instead.
  • Let clean items air-dry completely to minimize germ and mold growth.
  • Store clean feeding items in a protected area like a closed cabinet.