How to Sterilise and Clean Baby Bottles Properly (Step-by-Step)

Cleaning and sterilising sound like the same job, but they're two separate steps, and it helps to know the difference. Cleaning removes milk residue and dirt from the bottle. Sterilising, sometimes called sanitising, is an extra step that reduces the microorganisms left behind after cleaning. You clean first, then sterilise, never one instead of the other.

If you’re wondering how to sterilize baby bottles or how to clean baby bottles, this guide walks through the full routine in order: taking the bottle apart, washing every surface, choosing a sterilising method, then drying, storing and knowing when to replace parts.

Step 1: Wash your hands and disassemble every part

Start with clean hands, then take the bottle completely apart. If you’re learning how to clean baby bottles properly, this is an important first step. Separate:

• The bottle body
• The teat
• The screw ring or collar
• The cap
• The valve or any internal venting parts

Milk has a way of hiding in seams, vents and small components, so a bottle that's only half taken apart never really gets clean. Every piece needs to come away so every surface can be reached.

Step 2: Clean every surface

With everything apart, clean each piece thoroughly using the approved method for your bottle, either by hand or in the dishwasher (where the product allows it).

If you're washing by hand:

• Use hot, soapy water and a dedicated bottle brush kept just for feeding equipment
• Use a smaller teat brush to reach inside teats and narrow parts
• Get into every groove, thread and vent where residue collects
• Rinse thoroughly under clean running water afterwards, following your local guidance
• Cleaning is the step that does the heavy lifting, so it's worth being thorough here before you sterilise.
   

Step 3: Choose an approved sterilising method

If you’re wondering how to sterilize baby bottles, there are several methods you can use, depending on your routine and what your bottle is designed for. Always follow the care instructions for the specific product.

• Boiling: Maxi-Cosi Glass and PPSU bottles can be sterilised by boiling. Make sure all parts are suitable for this method and follow the product instructions. 
• Steam sterilising: Both bottle types are suitable for use with a steam steriliser. 
• Microwave self-sterilising: Maxi-Cosi Glass and PPSU bottles can also self-sterilise in the microwave. After washing and disassembling the bottle, add 30 ml of water to the base and follow the specific microwave instructions provided with the bottle. 

Step 4: air-dry and store components safely

Once sterilised, let the parts air-dry on a clean surface rather than rubbing them dry. Avoid drying internal feeding surfaces with a kitchen towel, which can transfer fibres and germs onto the very surfaces you've just cleaned.

When everything's dry, keep the clean parts protected and dry until you need them. Reassembling bottles once dry, or storing parts in a clean covered container, keeps them ready without picking up anything from the worktop in the meantime.

Frequently asked questions

How often should bottles be sterilised? 

Clean bottles thoroughly after every feed, and follow current guidance on how often to sterilise, which often depends on your baby's age. Whatever the frequency, cleaning always comes first, as sterilising a bottle that still has milk residue on it doesn't do the job properly.

Can a dishwasher sterilise baby bottles? 

Not on its own. A dishwasher cleans effectively but doesn't reliably sterilise unless it reaches and holds a high enough temperature. If you want bottles sterilised, use an approved sterilising method as a separate step after washing.

How should sterilised bottles be stored? 

Keep them clean, dry and protected until needed. Many parents reassemble the bottle once it's dry, or store the parts in a clean, covered container, so the sterilised surfaces don't pick anything up before the next feed.