When And How To Sterilize Baby’s Bottles? Our How-To Guide

Sterilizing baby’s bottle is an extra cleaning step that can help kill excess germs that still linger after washing. Learn when you’ll need to sterilize baby’s bottle, and all the different bottle sterilizing methods the CDC approves.

Keeping your baby’s bottles clean is a vital step for keeping their developing immune system healthy.

But even after washing your baby’s bottle, there’s one extra step you may sometimes need to keep bottles pristine. That step is sterilizing baby’s bottle, which usually involves using extra-hot water or steam to kill lingering germs on the bottle.

Today, we’ll cover when sterilizing a baby’s bottle is needed, and the different safe ways to sterilize baby’s bottle as recommended by the CDC.

When to sterilize baby’s bottle?

According to the CDC, sterilizing your baby’s bottle, as often as once a day, is beneficial for removing excess germs that regular washing doesn’t remove.

Still, how often you sterilize is up to you --- and sterilizing your baby’s bottle isn’t always necessary. If your home has access to clean, treated municipal water, you won’t need to sterilize your baby’s bottle very often.

In fact, if your baby is healthy and you’ve already sanitized a bottle for the first time, you probably shouldn’t sterilize it too often. Sterilizing too frequently could possibly cause damage to the bottle.

Even so, there are certain situations where it’s very important to sterilize your baby’s bottle.

Here are the times when sterilizing your baby’s bottle is vital:

When your baby is younger than 3 months old: Babies under 3 months of age have especially fragile immune systems. So, the CDC says sanitizing your baby’s bottles regularly is “particularly important” at this age. Once baby is older than 3 months, you can stop sterilizing their bottle regularly if they don’t have other health concerns.

If your baby is a preemie: If your baby was born prematurely, sanitizing their bottles also helps protect their especially vulnerable immune system.

If your baby has any health issues: Again, if baby has any health conditions that weaken their immune system, the CDC says sanitizing their bottles regularly is “particularly important.”

Before you use a new bottle for the first time: You don’t know how a bottle was handled during the manufacturing and packaging process. So always wash and sterilize each bottle right after you take it out of the package, to keep baby safe and healthy.

Before you first use a secondhand or borrowed bottle: Whenever you first plan to use a bottle that someone else used, wash and sanitize it first. This applies whether you’ve acquired the bottle from a thrift store or borrowed it from a friend/family member. You never know what it was exposed to in storage (and before storage).

Before you use a bottle previously used with a sibling: Just to be on the safe side, wash and sterilize your pre-loved bottle before your new little one first drinks from it.

If your baby is sick (or just recovered from an illness): Don’t risk re-infecting baby by using a bottle that may have lingering germs from their illness. Instead, sanitize the bottle daily while baby is still fighting the illness, to remove any bacteria and viruses that stick around after a wash.

If your young baby attends daycare: Since your little one comes in contact with more people at daycare (and there’s the rare but real risk bottles could get switched), you’ll probably want to sanitize your baby’s bottles after every time baby attends daycare.

If you don’t have access to clean drinking water: If you don’t have access to clean, treated drinking water, or your water supply is compromised, you’ll need to sterilize baby’s bottle regularly (preferably daily). You’ll also need to sterilize regularly if you use well water.

How To Sterilize Baby’s Bottle?

The CDC recommends sterilizing baby’s bottle using boiling water, using a dishwasher, or by using steam (a microwave or specialty bottle sanitizer). If none of these other options is available, the CDC also says you can sterilize with bleach as a last resort.

Use these methods to sterilize the bottle brush and basin that you use to wash the bottles, along with all the bottle parts.

Let’s go through each of the ways to sterilize baby’s bottle, step-by-step.

Sterilizing Baby’s Bottle With Boiling Water

  1. Wash all parts of the bottles before you sanitize, following CDC guidelines.
  2. Fill up a large clean pot with enough water to cover the bottles completely.
  3. Place the bottles upside down (or on their sides) in the water and let them fill with water. Make sure there aren’t any air bubbles trapped in the bottles.
  4. Place the other disassembled bottle parts in the water with the bottles.
  5. Bring the water to a boil, and let the bottles sterilize in the water for 5 minutes. (5 minutes is recommended by the CDC, but also check what the manufacturer recommends for your specific bottles)
  6. Turn the heat off, and remove the sterilized bottle parts using tongs.
  7. Place the bottle parts on a clean, dry dishcloth, and let them air dry. Don’t rub or pat the bottle parts dry with a dish towel, as this could transfer germs from the towel to the bottle.

Watch this video from Babylist for more on sterilizing a bottle in boiling water:

Sterilizing Baby’s Bottle In The Dishwasher

If you use hot water and the heated drying cycle (or a sanitizing cycle) while washing baby’s bottles in the dishwasher, the bottles will be sanitized while you wash them. Just make sure the bottles are dishwasher-safe before you use this method.

  1. Separate all the bottle parts.
  2. Rinse all the bottle parts under running water before you place them in the dishwasher.
  3. Place the bottle parts in the dishwasher. Place the small parts in a basket or mesh bag so they don’t fall into the dishwasher filter.
  4. Run the dishwasher with hot water and the heated dry setting.
  5. Wash your hands thoroughly before removing the bottle parts from the dishwasher.
  6. Place the bottle parts on a clean towel to air dry completely. Don’t rub or pat the bottle parts dry with a dish towel, as this could transfer germs from the towel to the bottle.

Sterilizing Baby’s Bottles With A Countertop Sterilizer

Countertop bottle sterilizers remove germs from baby’s bottles quickly and easily, and usually reach higher temperatures than boiling water (for an even more thorough clean). Simply follow the manufacturer’s instructions to sterilize baby’s bottles.

However, these electric sterilizers are the most expensive option for sterilizing baby’s bottle. So, you'll probably only want to buy one if you plan to sterilize bottles fairly often.

These countertop sterilizers use steam to sanitize bottles, but you can also use a microwave to sterilize bottles with steam.

Sterilizing Baby’s Bottles With Steam In The Microwave

  1. Wash all parts of the bottles before you sanitize, following CDC guidelines.
  2. Make sure the microwave is clean.
  3. Take apart the bottles.
  4. Place the nipples and rings in a microwave safe bowl. Set the bowl aside for now.
  5. Fill the bottles up halfway with water.
  6. Microwave the water-filled bottles for one to two minutes on the “high” setting.
  7. Let the bottles sit for a few minutes.
  8. Remove the bottles from the microwave using oven mitts.
  9. Dump the remaining water out, and let the bottles air dry.
  10. Fill the microwave-safe bowl with enough water to cover the nipples and rings.
  11. Microwave the bowl for one to two minutes.
  12. Let the bowl sit for a few minutes.
  13. Remove the bowl from the microwave using oven mitts.
  14. Dump out the remaining water, and let the bottle parts air dry.

You can also purchase a microwave sterilizer to make the steam process quicker and easier. Microwave sterilizers are usually around half the price of your typical countertop sterilizer. They enclose the bottles to make the steam-clean more thorough.

Sterilizing Baby’s Bottles With Bleach

If you can’t boil, steam, or use a dishwasher to sterilize baby’s bottles, the CDC does say that you can sterilize with bleach as a last resort.

  1. In a clean wash basin, combine 1-2 teaspoons of unscented bleach with 16 cups of water.
  2. Take apart the bottles.
  3. Submerge all parts of the bottles completely. Make sure the solution covers all parts of the bottles, and make sure there aren’t any air bubbles in the bottoms of the bottles.
  4. Soak the bottles and parts for 2-5 minutes.
  5. Remove the bottle parts with tongs. Don’t rinse as this could add germs back onto the bottles.
  6. Let the bottles air dry on a clean towel. (The bleach will break down as the bottles dry and won’t hurt baby. According to the CDC, this is similar to the bleaching used to sanitize restaurant dishes.)

A Note On Bottle Washing

Even if you don’t sterilize baby’s bottles, it’s still essential that you clean them after every feeding, as bacteria can thrive in residual or leftover breastmilk/formula. Use the dishwasher (as we described above) to both clean and sanitize, or thoroughly wash baby’s bottles by hand with soap and hot water following CDC guidelines. Be sure to wash the bottle brushes as well, and to wash the bottles in a dedicated basin if you wash them by hand.

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