My seven-week-old baby has been solely breast-fed so far, but we might put him onto bottles soon.

We've been given a steam sterilizer, but my mother-in-law expressed surprise when she saw it. "We just washed them with hot soapy water," she said.

I must admit I've always wondered how we coped for thousands of years before we had bottle sterilizers (though I guess we breast-fed for longer then, and also had a higher infant mortality rate, so maybe that's irrelevant).

Anyway - do I need to sterilize these bottles? If so, how old does he have to be before I can stop?

asked 22 Sep '09, 16:08

teedyay's gravatar image

accept rate: 0%


First child: yes, for 6 months. Second child: yes, in theory, for 2 months. Third child: steriwhat?

(07 Jan '10, 10:02) Benjol

12next »

My sister had this same question when she started her son on bottles. We found this information on babycenter to be helpful.

Baby Center - Sterilizing Bottles

This website suggests sterilizing until 1 year old because "By the time your baby is one year old she has started to produce her own antibodies and is more resistant to harmful germs" -babycenter

My sister used her steralizer because it was FASTER and EASIER than putting the bottles in the dishwasher. She didn't always want to run her entire dishwasher if she needed to wash just a few bottles and nothing else. And she liked that she could leave them in there to dry and for storage of clean bottles.

When I used bottles for 2 months (from 10-12months) with my daughter we had the Playtex Drop-Ins. I handwashed the nipple as soon as she had finished her bottle and threw the liner away or if the milk had sat in the bottle for a while I put the nipple in the dishwasher just so it could soak longer in the hot water. We have very hot water at our house also.


answered 22 Sep '09, 21:52

Sabrina's gravatar image

accept rate: 21%

The advice we received was to sterilize anything new by submerging in a pot of water brought to a rolling boil, and leave it submerged in the boiling water for at least five minutes. After that, subsequent washings in hot soapy water (or in the dishwasher) between uses are enough.

The "sterilize everything, every time" advice seems to date back to the days when the majority of people in North America didn't have safe municipal water. If you can't trust the safety of the water you're using to wash your bottles, you really should be sterilizing.


answered 22 Sep '09, 19:00

dave0's gravatar image

accept rate: 12%

We never sterilized bottles. We figured municipal tap water is generally safe, kids are going to get exposed to lots of germs from multiple sources anyway, and exposure to some germs is in fact beneficial in terms of giving something to a developing immune system to focus on.


answered 23 Sep '09, 09:40

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Simon 1
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edited 23 Sep '09, 09:57

Scott's gravatar image

Scott ♦♦

Hello there! You should sterilise the bottles and that can mean using the sterilizer or just washing them with very hot water, steaming the nozzles and then storing them with the nozzles facing into the bottles. Thats how we did it.

We were encouraged to breast feed only for the first six months so we used bottles from six month onwards.

We stopped sterilising bottles and pacifiers when she was twenty months.

Good luck!


answered 22 Sep '09, 19:06

Emi's gravatar image

accept rate: 19%

We sterilize bottles and teats in a container which stays sterile for 24 hours at a time and then gets refreshed. This is timed to fit in with me doing the washing up of an evening. the bottles are sterilized on demand, which for a baby means 15 minutes before anticipated demand, and is much easier once you've got junior into a routine.

Should you bother to sterilize? Yes you should, especially with newborns.

I've always thought it curious that anything being fed to our baby is sterilized with extreme prudence by my wife and I, but baby herself is happy to lie on the carpet cramming everything she finds into her mouth. We cannot prevent her becoming ill as a result of infection, but we can reduce the chances of it by sterilizing her bottles.

We do take on board the advice of other posters about training a developing immune system, however when a baby is newborn or very young they have a very undeveloped immune system at a time that they are very vulnerable. Sterilization in the first few months is absolutely necessary.


answered 28 Sep '09, 14:02

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edited 29 Sep '09, 08:55

Found a reference with information here (see the section on Sterilization):

(29 Sep '09, 09:55) Scott ♦♦

You're considering giving your 7-week old baby warm milk - a fantastic medium for growing bacteria - in bottles which aren't sterile! Yes, I would sterilise them first.

If you're using powdered formula you should be aware that it is not sterile. So you should read and follow the instructions carefully - particularly about temperatures of the water and how long you should store it. Ready made formula is sterile until you open it - but it is still a warm, nutrient-rich solution, almost perfectly designed for cultivating bacteria. Even if you're using expressed breast milk, the same thing applies. So, personally, I would to limit the number of bacteria in the bottle at the start however possible.


answered 26 Oct '09, 08:14

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Meg Stephenson
accept rate: 7%

We just put them in the dishwasher (top shelf) along with everything else, and maybe once a month would boil them on the stove.


answered 23 Sep '09, 04:18

Brandon's gravatar image

accept rate: 2%

I sterilized the bottles every week or so. I breast fed and pumped while at work so I used bottles still. Hope you continue to nurse, it's the best thing for your little one.


answered 23 Sep '09, 14:10

Michelle's gravatar image

accept rate: 3%


Well I won't, but my wife will. ;-)

Yes - we agree that breast milk is the best: we're only thinking of introducing bottles so that she can get more than two hours sleep at a time.

(24 Sep '09, 15:03) teedyay

:-) I am not sure if she has a pump, but if she does, I pumped so my husband could give our baby a bottle and I could get sleep. Good luck and congrats.

(24 Sep '09, 15:25) Michelle

I had to start bottle-feeding my son around 1 month. I usually only sterilize if he's sick. Otherwise, I wash all of his bottles in the dishwasher. In fact, my dishwasher has an antibacterial cycle that sanitizes. You may check yours for a similar cycle.


answered 29 Sep '09, 13:41

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Anna 1
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We never sterilized, just washed well in hot water with soap.

Unless you think your tap water is full of pathogens or your baby is immunocompromised, I'm not sure why true sterilization would be necessary. They're putting all sorts of other unsterilized things in their mouth all freaking day long. How will a sterile bottle (as opposed to just well cleaned) make or break things?

See also the hygiene hypothesis.


answered 29 Sep '09, 14:14

lgritz's gravatar image

accept rate: 14%

Surely the adherents of the hygiene hypothesis don't claim that babies who are not yet capable of grasping stuff to put in their mouths should be deliberately fed potentially harmful bacteria?

(27 Oct '09, 09:32) Meg Stephenson

I'm just saying that, realistically, they put icky stuff in their mouths all day long (you don't think a human nipple is sterile, do you?) and a hot-water-and-soap-washed bottle is probably the cleanest thing they are exposed to all day long. It probably doesn't make a dent in their bacteria exposure level to sterilize the bottle versus just clean it well.

(27 Oct '09, 13:15) lgritz

I agree - not only is human skin naturally ripe with bacteria, having baby saliva and breast milk contained on it by breast pads and nursing bras sure helps the proliferation of that bacteria.

moisture + heat + nutrients = great breeding ground for germs.

(29 Nov '09, 20:53) DarwinsMom

Breast milk contains antibodies which are made in response to any bacteria the nipple comes into contact with (see so the bacteria on a nipple are unlikely to be anywhere near as harmful as those in a plastic bottle.

(27 Jun '11, 13:42) Meg Stephenson
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Asked: 22 Sep '09, 16:08

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Last updated: 27 Jun '11, 21:02