Both microwave and electric steam sterilisers do the same core job — they use hot steam to kill the germs on your baby's bottles — and both are effective when used correctly. The real difference is convenience: an electric steam steriliser sits on your bench, holds more bottles and runs at the push of a button, while a microwave steriliser is smaller, cheaper and more portable but relies on your microwave and handles fewer bottles at a time. Which is “better” comes down to your kitchen, your budget and how many bottles you're getting through.

If you're setting up your feeding kit and staring at two similar-looking options, this guide breaks down exactly how they differ so you can choose with confidence.

At a glance

How each type works

Microwave steriliser

A microwave steriliser is a vented container (or a reusable bag) that you part-fill with water, load with bottles and teats, and place in your microwave. The microwave boils the water into steam, and that steam kills bacteria across the surfaces of your equipment in just a few minutes. Because it uses an appliance you already own, the unit itself is inexpensive and compact.

Electric steam steriliser

An electric steam steriliser is a standalone bench-top unit with its own heating element. You add water, load your bottles, and it generates steam automatically — no microwave required. Most have larger capacity and a hands-off cycle, and many keep contents sterile for several hours if you leave the lid closed.

Whichever you choose, remember that sterilising only works on clean equipment. Always wash bottles in hot soapy water first — our guide on how to sterilise baby bottles walks through the full routine.

Speed and capacity

Microwave sterilisers often finish their steam cycle faster — sometimes in just a couple of minutes — but they hold fewer bottles, so if you're sterilising a big batch you'll run several loads. Electric sterilisers take a little longer per cycle but fit more in one go, which usually makes them quicker overall for households getting through 6+ bottles a day. For newborns feeding around the clock, that larger capacity can be a real time-saver.

Cost, space and convenience

Microwave sterilisers win on price and storage — they're cheaper to buy and tuck away in a cupboard between uses. Electric sterilisers cost more and claim permanent bench space, but you get one-touch operation and don't tie up your microwave at mealtimes. If your kitchen is small or you're on a tight budget, a microwave steriliser makes a lot of sense. If bottles dominate your day and you'd rather press a button, the electric option earns its footprint.

Which is right for you?

• Choose a microwave steriliser if you want a low-cost option, have limited bench space, sterilise smaller batches, or want something that travels well for holidays and grandparents' houses.
• Choose an electric steam steriliser if you're sterilising lots of bottles daily, want a completely hands-off cycle, don't want to share time with your microwave, and have room to leave it out.
• Consider both — many families keep an electric steriliser at home and pack a compact microwave option (or steam bags) for travel.

Heading away? A packable option pairs perfectly with a portable bottle warmer so you can clean and warm bottles wherever you are. You'll find feeding bundles in our gift packs collection.

What about UV sterilisers?

Steam isn't the only option — UV sterilisers use ultraviolet light instead of heat, which is gentler on some materials and dries as it works. If you're weighing that up too, our comparison of UV steriliser vs steam steriliser covers the trade-offs in detail.

Keeping your steriliser working well

Whichever type you pick, mineral build-up from Australian tap water can affect performance over time. Descaling every few weeks keeps steam flowing properly — see our guides on cleaning a bottle steriliser and descaling a steriliser. Australia's Raising Children Network recommends sterilising feeding equipment for babies under 12 months, so it's worth having a routine that's easy to stick to.

Frequently asked questions

Is a microwave steriliser as good as an electric steam steriliser?

Yes — both use steam to kill germs and both are effective when used correctly. The difference is convenience and capacity, not how well they sterilise.

How long do bottles stay sterile after sterilising?

If you leave the lid closed and don't touch the contents, both microwave and electric sterilisers can keep bottles sterile for around 6 hours. Once opened, use or re-sterilise the bottles.

Which is faster, microwave or steam steriliser?

A microwave steriliser often has a shorter cycle, but holds fewer bottles. For larger loads an electric steam steriliser is usually faster overall because it does everything in one go.

Do you still need to wash bottles before sterilising?

Yes. Sterilising only works on clean surfaces, so always wash bottles and teats in hot soapy water and rinse before you sterilise them.

How long do you need to sterilise baby bottles for?

In Australia it's generally recommended to sterilise feeding equipment for babies under 12 months. After that, thorough washing in hot soapy water or the dishwasher is usually enough.

Can you use a microwave steriliser without a microwave?

No — a microwave steriliser needs a microwave to generate steam. If you don't have one, an electric steam steriliser or stovetop boiling method is the way to go.

This article is general information for Australian parents. Always follow the manufacturer's instructions for your steriliser, and check with your child health nurse if you're unsure. Source: Raising Children Network.