Bottle Warmer vs Bottle Sterilizer – Do You REALLY Need Both?

Balint Horvath, PhD

Writer, parent, and veteran of baby feeding battles.


One big struggle when comparing the bottle warmer vs bottle sterilizer options – do you really need either or both? I’m all for easy parenting so read on to find out about these two useful gadgets when bottle-feeding babies.

Bottle warmers and sterilizers serve different functions – the former for warming milk and the latter for sterilizing bottle-feeding equipment. They’re convenient, speedy, and easy to use. However, they’re not always necessary with cost-effective and simple alternatives available to parents. 

Key takeaways

  • Bottle warmers use hot water or steam to warm up infant formula or breast milk efficiently, safely, and quickly.
  • Bottle sterilizers use steam to efficiently eliminate 99.9% of germs and bacteria from baby bottles.
  • Multifunctional bottle warmers and sterilizers all-in-one appliances warm and sterilize baby bottles.
  • There are cost-effective and easy-to-use alternatives to warming and sterilizing baby bottles.
  • Parents don’t need both unless they want to save time and have the convenience of hands-free methods for warming and sterilizing bottles. 

Bottle warmer vs bottle sterilizer comparison table

Bottle WarmerBottle Sterilizer
Used to warm infant formula or breast milk.Used to sterilize bottles and remove germs and bacteria.
Uses hot water or steam to warm milk.Uses steam to eliminate 99.9% of bacteria, mold, and yeast.
Warms milk within 3 to 6 minutes (depending on brand).Sterilize bottles within 8 to 12 minutes (depending on brand)
Uses electricity or rechargeable batteriesUses electricity or rechargeable batteries
Can include sterilizing features in combo designs. Can include a warming feature in combo designs. 

How a bottle warmer works

Most bottle warmers are simple devices used to warm up your baby’s infant formula or breast milk to the right temperature for feeding. You’ll find electric and battery-powered models on the market with the second option being great for portability. 

Water is added to the bottle warmer which produces steam or hot water to warm up your baby’s milk. Every brand has its own unique features but most of them come with the following:

  • Heat and temperature-control settings
  • A defrosting setting
  • Auto shut-off switch (to prevent overheating)
  • Timer

When looking for the best bottle warmer for different brands of baby bottles, check out the Philips Avent Fast Baby Bottle Warmer. It fits most bottle brands and warms a 5-ounce bottle in just 3 minutes!

How a bottle sterilizer works

A bottle sterilizer is specifically designed to eliminate bacteria and germs from baby bottles. It can be used to sterilize bottle teats, pacifiers, teethers, and other accessories. These gadgets mostly run on electricity and water is added to produce steam which sterilizes 99.9% of bacteria, mold, and yeast (responsible for oral thrush.)

Top-quality brands such as Dr. Brown’s Sterilizer and Dryer include the following features:

  • Control panel with different settings
  • Auto shut-off feature
  • Removable accessory tray
  • Type 2 HEPA filters

When picking a bottle sterilizer make sure it’s compatible with most baby bottle brands. Read my article on whether MAM bottle fit all Tommee Tippee sterilizers for more useful information on the sterilizer at least from Tommee Tippee. 

Pros and cons of a bottle warmer

Pros of a bottle warmer

  • Fast: Warms formula or breast milk quickly and efficiently.
  • Safety features: Preserve nutrients in breast milk by not overheating the bottle contents.
  • Dual purpose: Some models include a sterilizing feature. They can also be used to defrost expressed frozen breast milk or baby food. 
  • Easy to use: A convenient and efficient way to warm up milk without needing extra items.

Cons of a bottle warmer

  • Space gobbler: This can clutter your kitchen countertop, especially in small kitchens. 
  • Expensive: Pricey compared to alternative warming methods such as using hot water to warm up your baby’s bottle. 

Pros and cons of a bottle sterilizer

Pros of a bottle sterilizer

  • Hygienic: Efficiently eradicates 99.9% of bacteria and germs.
  • Storage: This can be used to store bottles and accessories after being sterilized. If left unopened, the bottles will stay sterilized for up to 24 hours.
  • Easy to use: All you have to do is add some water, touch a button or two and the device does the rest for you. 

Cons of a bottle sterilizer

Does a bottle warmer sterilize bottles?

A bottle warmer doesn’t sterilize bottles. 

However, some brands such as the NCVI Bottle Warmer include a steam sterilizing feature which saves you from having two different appliances for warming and sanitizing your baby bottles. These multifunctional bottle warmers and sterilizer all-in-one combos can sterilize your bottles in 8 to 12 minutes. 

How to sterilize bottles without a sterilizer

There are several alternatives to sterilize baby bottles without a bottle sterilizer. Here’s an article where I compared using a dishwasher vs sterilzer vs washing by hand.

Boiling water

  • Disassemble the bottle parts and rinse under running water to remove residue.
  • Place the bottle and all the parts into a saucepan and pour water over them. Make sure the bottle and parts are fully submerged.
  • Boil for five minutes.
  • Remove with clean tongs and leave to air-dry on a drying rack or paper towels.


  • Before using this method, make sure the bottles and parts are dishwasher-safe.
  • Disassemble the bottle parts and rinse them under running water to remove residue.
  • Place the small, loose parts into a dishwasher basket to prevent them from getting lost during a wash cycle.
  • Place the bottles and parts on the top rack of the dishwasher.
  • Switch on a hot water cycle. Some dishwashers include a baby care wash cycle which produces steam to sterilize the bottles. 
  • Select the dry mode before removing the bottles from the dishwasher. 

Find a dishwasher, e.g. countertop, for baby bottles so you get features such as a baby care wash cycle and dry mode to clean and sterilize your bottle-feeding equipment properly. 

Bleach solution

  • Add 1 to 2 teaspoons of fragrant-free bleach to 16 cups of water in a clean bowl.
  • Place bottles and parts in the solution ensuring they’re fully submerged.
  • Soak for at least 2 minutes.
  • Remove with clean hands or tongs and leave to air-dry. The bleach will dissipate as the bottle dries. 

Watch this video and find out if sterilizing baby bottles is necessary!

Here’s an article I wrote about sterilizing baby bottles with bleach.

Is a sterilizer better than using boiling water?

Steaming and boiling water serve the same purpose so a bottle sterilizer isn’t necessarily better than using the traditional sanitizing method. Sterilizers and boiling water both use the same principle for sanitizing bottles – high temperatures are reached to eliminate most germs and bacteria. 

A portable bottle sterilizer is better when you’re traveling and don’t have access to clean water and facilities to boil it. A bottle sterilizer can be safer too, preventing you from scalding your hands or arms when using the boiling water method. 

Do I really need a bottle warmer and sterilizer?

A bottle warmer and sterilizer are useful when you don’t want to hassle with heating water to warm your baby’s milk or waste time washing bottles at the kitchen sink! They get on with the job, leaving you hands-free to hold your baby – pretty handy in the middle of the night. 

If you’re pumping and freezing breast milk (with a bottle), a bottle warmer can be particularly handy for defrosting, safely and quickly before a feed. They can also be used to sterilize breast pumps and parts. Bottle sterilizers give you peace of mind that your premie or immunocompromised baby is safe when bottle-feeding. 

However, if you’re looking for cost-effective alternatives, bottle warmers, and sterilizers aren’t an absolute necessity to include on your baby registry list.


Bottle warmers and sterilizers simplify warming and sterilizing baby bottles which I find really handy. Checking that Avent, Comotomo, Tommee Tippee baby bottles are dishwasher safe meant I could use this appliance for sanitizing bottle-feeding equipment without a sterilizer. 

So, to sum up, I would say no to sterilizers if you have a dishwasher. But, while we’ve used hot water often to warm our baby’s milk we do find a bottle warmer convenient most times!

Photo of author


I’m Balint, founder of this site and a father (and dad) to a baby-turned toddler. I found the world of babies so fascinating that I started a blog dedicated only to that topic. By the way, I studied physics, engineering (PhD, MSc), and therefore I do a thorough research when I write about something. Since it’s a blog, of course I also write about my personal experiences.

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