Helpful Tips

An In-Depth Look Into Sterilizing: Protecting Your Baby’s Developing Immune System

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How do you sterilize baby bottles? There are several options to choose from including buying a dishwasher bottle sterilizer, which will allow you to place the bottles in a protective container and sterilize them as you wash your other dishes, you can also opt to boil them on the stove, use bleach, sterilizing tablets, or buy a dedicated countertop bottle sterilizer.

Each of these methods will provide the results you’re looking for, but many of them can also require you to spend a lot of time cleaning in the kitchen, especially if you’re sterilizing your bottles daily. Most parents can agree that while it’s the priciest option, buying a dedicated countertop bottle sterilizer is the way to go. In the end, while the initial cost is high, it can save you several hours a week cleaning in the kitchen, which is also why most parents feel that these appliances are worth every penny.

So, how do you sterilize baby bottles? Choose a method that works the best for you and your family. Most parents agree that a countertop bottle sterilizer is the way to go, however, in some instances, dishwasher sterilizers are a great alternative. Additionally, you can also sterilize the bottles in the microwave, on the stovetop, or you can use sterilizing tablets or bleach. There are many options available that will work to kill any remaining bacteria that manage to survive the washing process.

Choosing the Right Sterilizing Process

As a new parent, you’re probably devoting a lot of time to researching how to sterilize baby bottles, learning about the best bottle sterilizers, and generally what you need to do to make your life easier during that particularly chaotic first year of life. Aside from the type of sterilizing method to use, you also have to decide what type of bottles you want to go with, whether they’re silicone, plastic, or glass. But regardless of the brand or type of material they’re made out of, you still need to decide which method will get your bottles as clean as possible in order to protect your infant’s delicate immune system.

This guide will cover everything you need to know concerning the best methods to use, which products I recommend to get the job done and some great tips on how to make your life easier when you’re dealing with a newborn and a sink full of dirty bottles.

Why and How Do You Sterilize Baby Bottles?


Sterilizing bottles is a step that can help to provide more protection against germs. Some parents believe that it’s a one-time deal in which the bottles should only be sterilized when they’re brought home from the store. After the initial sterilizing process most parents don’t bother to continue to ensure their infant’s bottles are in pristine condition and free of germs.

But other parents make it a point to sterilize a batch of bottles regularly. Another good reason you should sterilize them is if your infant has been sick. The last thing you want to do is risk re-infecting them by using bottles that aren’t as clean as they should be.

If your baby has health issues or they were born prematurely, then sterilizing the bottles regularly is a must to protect their weakened and developing immune system.

If you’re in a place where you don’t have access to clean water, or if your home is not a part of a municipality where clean drinking water is readily available, then you’ll need to have a solid sterilization process in place each time a bottle is cleaned. If you’re drinking well water, routine sterilization is also a must.

If you have good quality drinking water then you don’t have to sterilize your child’s bottles often. But why? Regularly sterilizing bottles can cause potential damage to the bottles which can allow certain chemicals to leach into the milk. This is especially true if you’re using bottles that contain BPA. Fortunately, this material was banned in baby bottle use way back in 2012, however, if you’re using older, second-hand bottles, then this will be a concern.

Sterilizing Frequency

How often you decide to sterilize your child’s bottles will be up to you. If you have a dishwasher then you may not feel that sterilizing the bottles is even necessary. But parents who want to be extra cautious will opt for a dedicated bottle sterilizer, such as the Philips AVENT 3-in-1 Electric Steam Sterilizer, which is very efficient and relies on steam to kill off bacteria and germs.

According to the CDC, sterilizing bottles should be done once a day for extra germ removal that goes beyond the standard dishwashing machine cleaning process.

If you’ve decided to sterilize your baby’s bottles on a regular basis, then you’ll want to do so until your infant is at least three months of age since their immune system will have matured enough by then that you won’t have to be quite so cautious concerning extra protection from germs. However, if your child was born prematurely then you may need to continue to sterilize their bottles until they’re six to nine months of age.

Inspect Bottles Often

You should avoid sterilizing your child’ s bottles if you notice any damage to the bottle itself. Glass bottles that are chipped or cracked must be thrown out immediately. Bottles that are made out of plastic that have any signs of warping, strong odors, cracks, or splits, should also be tossed out. Since you can also sterilize the nipples in a dedicated sterilizing machine, make sure you closely inspect them after each cycle to look for any noticeable signs of wear and tear.

Boiling Bottles on Your Stovetop

This is probably one of the most common ways moms and dads sterilize new bottles, but it’s not considered the most effective. Boiling the bottles in a large pot of water will work by raising the temperature high enough to kill any bacteria that has remained after washing.

To do, you’ll place the nipples, caps, covers, and clean bottles in a large pot on a back burner. You should add enough water to cover all of the bottles and pieces and ensure there are no air bubbles. Bring the water up to boil and allow the bottles and accessories to boil for five minutes only. Any longer and you’ll risk damaging them. Next, shut the burner off and allow the water to cool.

Before you handle the bottles again, make sure you wash your hands once more. Take the bottles and accessories out of the water and place them on a towel to air dry.

Countertop Sterilizers

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Some parents will sleep better knowing that their infant’s bottles are sterilized regularly. If this sounds like you, then buying a dedicated countertop bottle sterilizer will probably be the best option. These appliances are pretty powerful and do an excellent job of killing off germs, bacteria, and even viruses. Using electric steam, these machines can reach an even higher temperature than boiling water, which means that can kill more mold and bacteria. While this option is definitely a little pricier than boiling your bottles in a pot of water on the stove, it’s probably the fastest and easiest way to go about this important task. Plus, you can also sanitize other bottle parts such as the rings, covers, and even the nipples. Some moms will even toss in baby forks and spoons, pacifiers, and teething rings.

Using Bleach

If you don’t have access to a dishwasher, steam, or boiling water, the CDC has stated that using bleach to sterilize baby bottles is a great alternative. For this method, you’ll use sixteen cups of hot water and just one teaspoon of unscented bleach. The bottles should be fully submerged in the mixture. During this process make sure you take special care to avoid any air bubbles in the bottles. The bottles should sit soaking in the sink for five to eight minutes. Once the time is up, remove the bottles using a pair of tongs.

The bottles should then be placed on a clean towel and allowed to air dry. During this time, avoid rinsing the bottles out since any remaining bleach left in the bottles will quickly break down during the drying process, so there’s no cause for concern that any residual bleach will harm your infant.

Sterilizing Tablets

When you’re out on the road, far from home and you don’t have your handy bottle sterilizer with you, you can opt for chlorine-based, food-grade sterilizing tablets. These tablets are said to be just as effective at killing bacteria and mold as other sterilizing methods. However, it’s important that you carefully follow the included instructions to ensure that you use the product correctly.

How to Sterilize Baby Bottles in Microwave

If you don’t have a dedicated sterilizing machine, you can also use the microwave to get the job done, although it’s not nearly as efficient. The whole goal of sterilizing is to kill bacteria in the bottles via high temperatures.

To use your microwave for this task, make sure you clean it out prior to the sterilization process. Next, you’ll fill each bottle halfway with distilled water, then set the microwave on high for two to three minutes.

Before you remove the bottles from the microwave, make sure you’re wearing oven mitts to avoid burns. The bottles should be carefully removed to prevent spills and scalding the skin.

Another great option is to buy a microwave bottle sterilizer. These sterilizers use the power of steam to clean the bottles. The design encloses the entire bottle in a type of plastic casing which means each bottle will get a much more thorough cleaning.


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If you decide to toss your bottles in the dishwasher, make sure the bottles you’re using are deemed dishwasher safe. If you place the dishwasher on the hottest setting, it should thoroughly clean bottles, nipples, and other parts. You can also toss in teething rings and small toys. However, I recommend placing them on the top rack of the dishwasher to prevent warping.

To get your bottles ready for the dishwasher, rinse all of the bottles out and all the parts, careful to entirely remove any remaining dried on milk. You can purchase a dishwasher safe basket for the nipples, valves, rings, and other small parts in order to prevent them from falling to the very bottom of the dishwasher.

Once the cleaning cycle is up, remove the bottles and accessories and allow them to air dry on a clean towel.

Washing Bottles By Hand

Whether you decide to boil your bottles on the stovetop or use a countertop sterilizer, the bottles must still be thoroughly cleaned prior to sterilization. Infants and newborns with an underdeveloped immune system will be vulnerable to fungi, parasites, bacteria, and viruses, which can result in illness. These germs can grow very quickly in formula or breastmilk if the bottles haven’t been cleaned well. Washing the bottles by hand or via the dishwasher using soap and hot water is all you need to remove dried on milk.

Take Extra Precautions When Washing Bottles

If you don’t have a dishwasher or just want to wash them by hand, make sure you do so in a special container that you will only use for washing the bottles, as opposed to washing them directly in the sink. This will help to prevent any type of cross-contamination. You should also use a special bottle cleaning brush, which will ensure you’re able to remove any dried-on milk that has gotten stuck at the very bottom of the bottles.

  • But before you start washing, make sure you wash your hands first.
  • Next, you’ll separate the bottles and their parts and rinse out each nipple, valve, ring, and bottle under hot water to remove as much dried-on milk as possible. Remember to avoid setting the bottles in the sink. Next, fill up the appointed container with hot soapy water.
  • Scrub out each of the pieces and bottles using a dedicated cleaning tool such as a bottle brush. Make sure you take special care to clean each crevice and the bottoms of each bottle.
  • For the nipples, use another brush or buy a bottle brush that comes equipped with a nipple cleaning tool. When cleaning the nipples make sure you make a point of flushing water through the holes in the tip to ensure there is no dried milk clogging the holes.
  • Rinse everything under hot running water and allow all of your baby bottle gear to air dry on a clean towel.

How Long Do You Sterilize Bottles?

This is dependent on the type of sterilization process you’re using. As an example, when you boil the bottles on a stovetop, you will only need to boil them for five minutes. If you’re using a countertop sterilizer, you will set it for the sterilization process and wait for the process to be completed. The same will apply if you’re using a dishwasher sterilizer basket, in which case you would wait for the dishwasher’s washing cycle to be completed before removing the bottles.

How to Sterilize Plastic Baby Bottles

If you’ve been following along and made it this far in my guide, then you know that as a baby grows their immune system is also growing. When a baby is exposed to germs in the home during their first year of life, it impacts how their immune system develops, and in many instances, this type of exposure can strengthen their immune system, which is definitely a good thing.

However, there is a big difference between bad bacteria and immune-building bacteria. Usually, disease-causing germs can be found on items that will come into contact with your infant’s mouth. Washing a bottle in hot soapy water is key, yet some types of harmful bacteria will be able to survive even the toughest scrubbing.

Bacteria can cultivate through transfer and this includes handling bottles and their accessories without washing your hands. Additionally, they can also cultivate bacteria from exposure, such as leaving a washed bottle on the same counter that you’ve prepared foods such as raw chicken and beef.

Because of this, many parents have made it a point to sterilize their bottles, which as you know by now, will effectively eliminate any bacteria that has survived the washing process.

As I’ve touched on earlier, bottle sterilization can be done in a number of ways, such as:

  • Sterilizing tablets
  • Countertop sterilizers
  • Sterilizer baskets for the dishwasher
  • Boiling the bottles on the stove

Whichever method you choose, make sure you follow the instructions carefully in terms of usage and sterilization time.

A Note About Air Dying

When you allow the bottles to air dry, you need to take special care to prevent the bottles from making contact with the countertop. Some parents will use a clean dishtowel, while others will purchase a special bottle drying rack for extra protection and a faster drying time. Many of these drying racks feature a raised drying platform, which completely eliminates any contact with the counter and any appliances on the counter.

The base will collect water so your countertop will remain dry. If you’re worried about the rack taking up counter space, then buy a folding rack, which you can fold back up and store away once the bottles are dry.

Related Questions

How Can You Sterilize Bottles When You Travel?

In my breast milk guide, I discussed the importance of storing breast milk as you travel. Ensuring your bottles are sterilized and ready to go is another part of traveling with your infant that you should figure out before your trip. The options available will depend on how you travel and where you’re staying. If you’re staying with family, then you can bring along your usual sterilization equipment. However, if you’re staying at a hotel, things can get tricky. If your room has a microwave, then you can always rely on it to sterilize your bottles. You can even pick up a special microwave-safe steam sterilizing bag for bottles, which can make the entire process that much easier. Remember, plan well in advance in order to make traveling easier on both you and your baby.

Do You Have to Sterilize Bottles Before the First Use?

These days, manufacturing processes are said to be much safer than what they were just five years ago. But like most parents, you want to go above and beyond for your child and ensure there are no harmful chemicals, bacteria, or any type of contaminant on or in the bottles. For this reason, I definitely recommend sterilizing all of the bottles, and anything that’s designed to go into your child’s mouth, before you use it. This includes pacifiers, teething rings, teething jewelry, and sippy cups.

How Do You Store Sterilize Baby Bottles?

Some parents will leave sterilized bottles inside the sterilizer until they’re ready for use. Other parents will store them in the cupboard as usual, but only after reassembling the bottles and applying the included cap. This can help to prevent dust, debris, and any other types of contaminants from making contact with the nipple. You can also store the nipples separately in an airtight container or ziplock bag for extra protection.

Final Thoughts

I hope this sterilizing guide has helped you to decide which sterilizing method to go with. Remember, not only should the method you choose make life a little easier for both parents, but it should also be effective and efficient. Most parents can agree that a countertop bottle sterilizer is the way to go. While some models can be a little pricey, they will definitely take a lot of the heavy lifting out of the entire sterilizing process, saving you plenty of time in the kitchen and freeing you up to take care of other chores around the home.