How to Clean and Sterilise Baby Bottles

The short answer

Clean bottles and every removable part after every feed, then let every item air-dry completely. Cleaning must happen before any additional sanitising or sterilising step. The U.S. Centers for Disease Control and Prevention (CDC) and the U.K. National Health Service (NHS) give different national protocols: follow the one that applies where you live, alongside the equipment manufacturer's instructions and any individual direction from your baby's clinician.

When to get help now

The CDC says that Cronobacter infection in an infant under 1 year usually starts with fever and poor feeding, excessive crying, or very low energy. Some babies may also have seizures. The CDC says a baby with these symptoms should be taken to a medical provider as soon as possible. These signs do not let a parent diagnose an infection; a clinician assesses the baby.

For a baby or child under 5, the NHS says to call 999 or go to A&E for any one of these 11 signs:

• Swollen lips, tongue, or throat with difficulty swallowing or talking.
• Very fast breathing or difficulty breathing; the child may grunt or suck in the tummy while breathing.
• Blue, grey, pale, or blotchy skin, lips, or tongue. On black or brown skin, the NHS says this may be easier to see on the palms or soles.
• Skin that feels cold or damp.
• A rash that does not fade when pressed.
• A temperature of 38C or higher in a baby under 3 months, or 39C or higher in a baby aged 3 to 6 months.
• A temperature below 36C, feeling cold to touch, or shivering.
• A weak, high-pitched, or continuous cry.
• Fainting, being difficult to wake, or being unable to wake.
• No pee in the past 12 hours.
• A seizure.

The NHS also says to call NHS 111 when you are worried about any symptom or do not know what to do. Those are U.K. routes.

This page explains general bottle-hygiene guidance. It cannot assess an exposure, illness, or individual baby's needs. Decisions about a specific baby belong to the clinician who knows that baby's history.

If you are worried about your baby right now, you do not need a reason that satisfies anyone. Call your pediatrician, your local out-of-hours service, or your emergency number. Trusting your instinct is the correct response.

What is the difference between cleaning and sterilising?

Cleaning removes milk and other residue from feeding items. The CDC hand-washing method uses soap, hot water, a dedicated basin, and a dedicated brush. Sanitising is an additional step after cleaning. The NHS likewise instructs caregivers to wash and rinse bottle-feeding equipment before sterilising it.

The agencies use different terms and protocols. The CDC calls its extra step “sanitizing.” The NHS calls its extra step “sterilising.” Their directions are not interchangeable: for example, the CDC's boiling method uses 5 minutes, while the NHS boiling method requires at least 10 minutes. Follow one applicable protocol rather than combining details from both.

Which bottle parts need cleaning?

The CDC includes bottles, nipples, rings, caps, valves, and membranes among infant feeding items. Take the bottle apart so that each removable component can be washed. Check the manufacturer's instructions before putting any component in a dishwasher, steam system, chemical solution, or boiling water.

The NHS tells caregivers to check the bottle and teat for damage before cleaning and sterilising. The CDC also advises inspecting used bottles before each use and discarding them at the first sign of damage or wear. Follow the manufacturer when deciding when a valve, membrane, teat, or other component must be replaced.

The CDC says bottles should be cleaned after every feeding. It warns that germs can grow quickly when breast milk or formula is added to a partially used bottle, or when a used bottle is rinsed instead of cleaned. A rinse is therefore not the full cleaning process.

How do you wash bottles by hand?

The CDC's current hand-washing process is:

1. Wash your hands with soap and water for 20 seconds.
2. Separate all bottle parts.
3. Rinse each part under running water. Do not place the parts directly in the sink.
4. Put the parts in a clean basin used only for infant feeding items.
5. Fill that basin with hot water and add soap.
6. Scrub each item with a clean brush used only for infant feeding items.
7. Squeeze water through nipple holes.
8. Rinse the items under running water, or hold them completely under fresh water in a separate basin used only for feeding items.
9. Put the parts, basin, and brush on a clean unused dish towel or paper towel in an area protected from dirt and dust.
10. Let everything air-dry thoroughly.

The CDC says not to rub or pat feeding items dry with a dish towel because the towel may transfer germs to them. It also tells caregivers to rinse the basin and brush and let both air-dry after every use. The CDC says to wash the basin and brush every few days. For a baby younger than 2 months, born prematurely, or with a weakened immune system, it says to wash them after every use.

Can bottles go in the dishwasher?

Only use the dishwasher if the manufacturer says every relevant part is dishwasher-safe. The CDC says to separate the parts, rinse them under running water, and put small pieces in a closed-top basket or mesh laundry bag so they do not fall into the dishwasher filter.

If possible, the CDC says to use hot water and a heated drying cycle or sanitising setting. Wash your hands before removing the items. If a part is still wet, place it on a clean unused dish towel or paper towel and let it finish air-drying. Do not rub or pat it dry.

Under CDC guidance, a dishwasher using hot water and heated drying, or a sanitising setting, removes the need for a separate sanitising step. The NHS says that a dishwasher cleans bottle-feeding equipment but does not sterilise it. This is a genuine difference between the two national protocols.

When does the CDC say to sanitise bottles?

For extra germ removal, the CDC says to sanitise feeding items at least once daily. It says this is particularly important when a baby is younger than 2 months, was born prematurely, or has a weakened immune system. It also says daily sanitising may not be necessary for older, healthy babies when items are cleaned carefully after each use.

The CDC gives three additional methods after cleaning:

• Boiling: cover disassembled boil-safe items with water, bring the pot to a boil, boil for 5 minutes, and remove the items with clean tongs.
• Steam: put disassembled items in a microwave or plug-in steam system and follow the manufacturer's instructions for sanitising, cooling, and drying.
• Bleach: this is an alternative when boiling, steaming, or a dishwasher cannot be used. Follow the CDC's current measured recipe and sequence exactly rather than using a remembered household mixture.

The bleach instructions include full submersion, removal with clean hands or tongs, no rinsing after sanitising, and complete air-drying. Because the concentration, contact time, and sequence are part of one official method, read the live CDC page before using it.

How does the NHS say to sterilise bottles?

The NHS instructions apply to equipment used for expressed breast milk and first infant formula. Before sterilising, wash hands, clean the work surface with hot soapy water, check the bottle and teat for damage, wash them in hot soapy water with a clean bottle brush, and rinse everything in clean cold running water.

The NHS then gives three routes:

• Steam sterilising: use an electric or microwave steriliser according to its manufacturer instructions, with bottle and teat openings facing down.
• Cold-water sterilising: follow the product instructions, change the solution every 24 hours, leave equipment in it for at least 30 minutes, remove trapped air, and keep everything below the solution with the submerger.
• Boiling: confirm the items are safe to boil, keep them below the water, and boil for at least 10 minutes.

The NHS warns never to leave hot pans or liquids unattended. It also notes that boiling can damage teats faster. Follow the equipment instructions.

How should clean bottles dry and be stored?

The CDC says clean feeding items, brushes, and basins should air-dry thoroughly before storage to help prevent germs and mould from growing. When the items are completely dry, wash your hands, put the bottle parts back together, and place them in a clean protected area, such as a closed kitchen cabinet used only for clean dishes.

If you use a drying rack, the CDC says to reserve it for infant feeding items. It says to wash, sanitise, and thoroughly dry the rack every few days, or at least daily when the baby is younger than 2 months, was born prematurely, or has a weakened immune system.

For a powdered-formula scoop, the CDC says not to clean it unless it becomes dirty. If it falls on the floor or is otherwise soiled, clean it as carefully as the bottles and let it air-dry completely before returning it to the container. Keeping liquid out of powdered formula is the stated reason.

Does clean equipment make prepared formula safe indefinitely?

No. Bottle hygiene and formula preparation are separate controls. The CDC says to use the amount of water on the formula container, measure the water first, and then add the powder. It says too much water may leave the formula unable to meet a baby's nutritional needs, while too little may make the kidneys and digestive system work too hard and can cause dehydration.

For storage in the United States, the CDC says to use prepared formula within 2 hours of preparation and within 1 hour after feeding begins. If feeding has not started within 2 hours, refrigerate the bottle immediately and use it within 24 hours. Formula left in a bottle after a feed must be discarded because the combination of formula and saliva can allow bacteria to grow.

The U.K. process differs. The NHS says to prepare feeds one at a time, using fresh cold tap water that has been boiled and left to cool for no more than 30 minutes so that it remains at least 70C. Follow the formula label and the national instructions where you live. Never change the water-to-powder ratio.

The CDC says formula does not need warming. If warming is chosen, it says never to use a microwave because uneven heating can create hot spots that burn a baby's mouth and throat.

If feeding frequency is the concern, see how often a newborn feeds. If output falls or a baby becomes difficult to wake, use the urgent routes in signs of dehydration in babies and contact the baby's clinician.

A repeatable cleaning checklist

After each feed:

• Separate every removable part.
• Rinse and wash by hand using the CDC sequence, or use a compatible dishwasher under the applicable national guidance.
• Complete the applicable sanitising or sterilising step.
• Let every item air-dry thoroughly in a protected area.
• Store only fully dry equipment with clean hands.
• Discard formula left after a feed under the applicable storage rule.
• Check the bottle, teat, and other parts for damage before reuse.

This checklist does not replace any step on the live agency page or in the equipment manual. If a neonatal unit, pediatrician, or public-health service has given instructions for a premature baby or a baby with a medical condition, follow that individual plan.

Sources

• CDC, “How to Clean, Sanitize, and Store Infant Feeding Items Frequently Asked Questions” (16 April 2024) — bottle parts, every-feed cleaning, hand and dishwasher methods, U.S. sanitising methods, drying, and storage.
• NHS Best Start in Life, “How to sterilise feeding equipment” (accessed 1 September 2026) — U.K. preparation steps and steam, cold-water, and boiling methods.
• CDC, “Infant Formula Preparation and Storage” (14 May 2026) — mixing order, storage times, leftovers, warming, and additional precautions.
• NHS Best Start in Life, “How to make up a bottle feed” (accessed 1 September 2026) — U.K. one-feed-at-a-time preparation and the at-least-70C route.
• CDC, “About Cronobacter Infection” (29 September 2025) — infant signs, medical routing, and contamination routes.
• NHS, “When to get urgent medical help for babies and children under 5” (reviewed 6 August 2026) — the 11 immediate-action signs and the NHS 111 route.

Independent guidance, not medical advice. We do not diagnose or recommend treatments or doses. For any concern about your baby, contact your pediatrician or local emergency service.