Guide to Bottle Feeding
How to prepare infant formula and feed your baby safely

(Content revised 02/2025)

Considerations for feeding baby with infant formula

If for some reason, parents cannot breastfeed or have decided not to give their baby breastmilk, they can only give them infant formula in their first few months of life.

Parents should understand that once their baby is fed with infant formula, the baby's desire to be breastfed will reduce and thus decrease mother's milk production.

Infant formula is costly. Parents may have to spend a considerable amount of money on the infant formula in the first year (for example, a can of 900 gram infant formula costs $2761 and a baby consumes 3.5 cans a month. That would cost over $10,000 in the first year).

Infant formula is available in two forms: the commercially sterile ready-to-feed liquid formula and powdered infant formula. Powdered infant formula is not a sterile product. Safe preparation of formula milk and use of properly sterilised feeding equipment is essential to protect the baby from the risk of infection.

1Infant Formula Price Survey Price Information collected from Retail Outlets by Consumer Council (Jan 2025). The median price of 900 gram infant formula.

Breastmilk is more than the baby's natural food…

Breastmilk is the ideal source of nutrients for the baby's growth and development. It also contains antibodies and living immune cells from the mother, enzymes, and other valuable substances that cannot be obtained from infant formula. These ingredients enhance the baby's immunity and reduce the chance of being admitted to hospital because of chest infection or diarrhoea. Breastmilk also helps the digestion and absorption of nutrients.

Breastfeeding enhances bonding between mother and baby, and makes the baby feel safe. Breastfeeding is also convenient, time-saving, money-saving and environmentally friendly. Breastfeeding benefits mothers too. Breastfeeding helps the uterus return to its normal size and reduces the chance of heavy bleeding after delivery. Breastfeeding also protects mothers from ovarian and breast cancer. Mothers breastfeeding for a longer period also have a lower risk of developing hypertension and diabetes.

Contents

What is infant formula?

  • Most infant formulae are made from cow's milk that has been treated to make it suitable for babies. There are also infant formulae made from goat's milk or soy protein.
  • The nutritional compositions of infant formulae must meet the standards of the Codex Alimentarius Commission, and satisfy, by itself, the nutritional requirements of infants during the first months of life up to the introduction of appropriate complementary feeding.2

How to choose a suitable infant formula?

  • Cow's milk-based infant formulae, often called "Stage 1 formulae", are suitable for healthy babies from birth.
  • Soy-based infant formulae can be used when the baby has galactosaemia or when they cannot have formulae made from cow's milk for cultural or religious reasons.
  • Nutritional composition of infant formulae are similar. You can make your decision according to the market supply or personal choice. If needed, you can ask your doctor or nurse for advice. In general, switching to another brand should not affect the baby's health.
  • Premature infants and infants with weakened immune systems are more vulnerable to bacterial infections. Where possible, the sterile ready-to-feed liquid infant formulae should be chosen.3

Unless advised by a doctor, babies under 6 months should only be given infant formula.

After 6 months, they can continue with infant formula. After 12 months old, they can start to drink full fat cow's milk.

2Nutritional composition of infant formula sold in Hong Kong is under legislative regulation. It should provide nutrition label(s) showing energy and nutrient contents. Visit the webpage of the Centre for Food Safety for details.

3Centre for Food Safety, Food and Environmental Hygiene Department. Food Safety Focus (28th Issue, November 2008).

Q. Is there any infant formula that reduces the baby's risk of getting allergy?

  • Current research does not support any infant formula product having an advantage over another in preventing healthy babies from developing allergies. If there is a family member suffering from an allergy, please seek your doctor's advice if you consider feeding your baby infant formula.

Q. What are the choices of infant formula for infants with cow's milk allergy?

  • Consult your doctor if you worry your baby is allergic to cow's milk. For infants who are diagnosed with cow's milk protein allergy, doctors may prescribe special formulae4, such as extensively hydrolysed formula or amino acid formula. It is important to follow doctors' instructions on choice of products.
  • Soy-based formulae or goat's milk formulae are not suitable for babies with cow's milk allergy because these babies may also be allergic to soy or goat's milk.

4"Special formula" means formula for special medical purposes for infants and young children.

Q. My baby passes hard stools. Is it related to the infant formula?

  • Generally speaking, it is not common for babies to have constipation in the first six months of age. However, constipation may occur temporarily when they switch from breastmilk to infant formula or switch to a new brand of formula. Besides, babies may be constipated if the infant formula is not prepared correctly and less water is added. Check the instructions on the formula package. Make sure the correct amount of water and powdered infant formula are used in making up a feed. Always put water into the feeding bottle first and then add the formula powder. If needed, you can give your baby a small amount of water in between meals.

Q. How do I help my baby switch to another brand of infant formula?

  • There is no specific rule on how to switch infant formula brands. If your baby accepts new tastes quite easily, parents can simply switch to the new brand in one go. Alternatively, you may increase the number of feeds of the new brand gradually.
  • The milk powder and water ratio may differ with different brands. You should not mix different brands of milk powder when preparing one feed.
  • On switching to another formula brand, you may notice a change in your baby's stool. This is usually due to a subtle difference in composition of ingredients amongst different brands, and does not affect the baby's health.

<Follow-on formula >is not suitable for babies under 6 months

Follow-on formula (that is "Stage 2" or "Stage 3 formula") contains much more protein. The excess protein may overload the immature kidneys of newborn babies and may lead to dehydration, diarrhoea or damage to the brain.

Types of milk to avoid in babies under one year old:

  • Goat's milk
  • Soy milk
  • Evaporated milk
  • Condensed milk
  • Full fat milk or low fat milk

What equipment is needed for bottle feeding?

  • Sterilising equipment (such as a large pot, electric or microwave steam steriliser)
  • Feeding bottles and teats of appropriate size and material
  • Bottle brush and teat brush
  • Tongs for picking up feeding bottles and teats after sterilising

How to choose feeding bottles and teats?

Choosing feeding bottles

  • Use glass bottles or plastic bottles that are bisphenol A (BPA) free.
  • The colours of the decorations and markings on the bottles should not chip off easily and should be harmless.
  • The bottles should be clear with easy to read markings on the side. The inner part of bottles should be easily visible.
  • They should be easy to clean.
  • The bottle sizes should be appropriate.

Choosing teats

  • The size of the teats should be appropriate for the age of the baby.
  • The shape and material of the teat generally do not make a difference in feeding. Latex teats are soft and flexible. Silicone teats are more durable and can stay in shape longer.
  • The hole of the teat should be of an appropriate size that the milk will drip at a rate of about one drop per second when the bottle is tilted. If the hole is too small, the baby may get tired from sucking. If it is too big, the baby may choke on the milk because the formula comes out too fast.
  • Use bottles and teats that comply with the safety standards (such as the European standard EN 14350). Check that the bottles are bisphenol A (BPA) free.
  • Replace the bottles when the markings become blurred.
  • Throw away broken or damaged bottles and teats.

How to clean, sterilise and store feeding equipment?

(Feeding equipment cleaning, sterilisation and storage video)

All feeding equipment for breastmilk or infant formula must be washed thoroughly and sterilised. They include feeding bottles, teats, bottle covers, rings, and other accessories such as tongs and knives.

1. Cleaning feeding equipment

  • Before cleaning the feeding equipment, wash your hands with soap and water. Clean the work surface with hot soapy water.
  • Wash feeding bottles, teats and tongs in hot soapy water immediately after feeding by using a clean bottle brush. Ensure that there are no remains of milk left inside. Then rinse the equipment thoroughly in running water.

Bacteria can grow easily in the cracks. Check carefully when washing bottles and teats. Discard damaged ones.

2. Sterilising the feeding equipment

You can choose from the following methods for sterilising the feeding equipment:

  1. Sterilising by boiling
    • Make sure the equipment is designed to be boiled.
    • Put the cleaned equipment into a large pot. Cover all items with water and make sure no air bubbles are trapped inside the equipment.
    • Place the lid on the pot. Boil the feeding equipment for 5-10 minutes. Then turn off the heat and leave the water to cool. Please refer to 'Storing the sterilised feeding equipment' for taking out feeding equipment.
    • Keep the pot covered until the feeding equipment is needed. If the lid has been opened, the content requires to be sterilised again.
  2. Sterilising with steam (with an electric or microwave steriliser)
    • Follow the manufacturer's instructions carefully.
    • Make sure that the openings of the bottles and teats face downwards in the steriliser.
    • Open the steriliser lid and remove the feeding equipment only when you are going to prepare a feed. Please refer to 'Storing the sterilised feeding equipment' for taking out feeding equipment.
    • If the steriliser has been opened, the content requires to be sterilised again.
  3. Sterilising with chemicals
    • Follow the manufacturer's instructions for sterilisation and changing the sterilising solution. For most products, the solution should be changed every 24 hours.
    • Put the feeding equipment into the sterilising solution. Make sure no air bubbles are trapped inside the bottles and teats. Place a floating cover over the equipment to keep all items submerged in the sterilising solution.

3. Storing the sterilised feeding equipment

  • It is best to take the feeding equipment out just before use.
  • Before taking out the equipment from the steriliser, wash your hands thoroughly with soap and water, and then dry them with a clean towel. (Please refer to the leaflet "Hand Hygiene --- an easy and effective way to prevent infection".)
  • If the sterilised feeding bottles and other equipment are not used straightaway, take them out with sterilised tongs and put the teats and caps back onto the bottles. Store everything in a cleaned and covered container.
  • Boil-sterilised equipment must be used within 24 hours. When using other sterilisation methods, the storage time of the equipment must be in accordance with the manufacturer's instructions.

How to prepare an infant formula feed safely?

(Formula feed preparation video)

Follow these steps:

  1. Boil the water

    Boil fresh tap water or distilled water. If you use an electric kettle, the water should be boiled until the electric supply of the kettle switches off.

  2. Clean the surface for preparing the feed and wash your hands

    Clean and disinfect the surface on which you are going to make up the infant formula feed. Wash your hands with soap and water, and dry them with a clean towel or tissue paper.

  3. Take out the sterilised bottle

    Take a sterilised bottle and shake off the water inside the bottle and the teat. If you are using chemical sterilisation, please follow the manufacturer's instructions.

    Bottled water

    • Some bottled water (e.g. mineral water) are not suitable for making up infant formula because their mineral content may exceed the baby's needs.5
    • If bottled distilled water is used, boil it before making up infant formula feeds.

5National Health Service. How to make up baby formula. Retrieved December 6, 2024.

Read the instructions on how to make a feed on the package of the infant formula. Measure the amount of water and milk powder accurately.

Use water no less than 70°C to make up formula feeds. Make up a fresh bottle of formula each time your baby needs a feed. These practices reduce the risk of infections in your baby.

  1. Fill the feeding bottle with the correct amount of hot water

    Put the correct amount of hot water into the sterilised bottle. The water should be no cooler than 70ºC. To achieve this temperature, cool the boiled water at room temperature for no longer than 30 minutes.

  2. Add the correct amount of powdered infant formula

    Measure the formula powder with the scoop provided in the package or can. Loosely fill the scoop with formula powder, then level it off without compressing the powder. Measure one level scoop of formula powder each time. Add the exact amount of powdered formula to the bottle filled with water according to the instructions on the package.

    Key facts

    Make up infant formula feeds with hot water of temperature no less than 70ºC. This kills harmful bacteria which may be present in the powdered infant formula.6

    6World Health Organization in collaboration with Food and Agriculture Organization of the United Nations. 2007. Safe preparation, storage and handling of powdered infant formula: guidelines. World Health Organization.

  3. Gently shake the bottle

    Attach the teat, cap and other accessories to the bottle. Shake/swirl until the powder dissolves.

  4. Cool the feed

    Cool the feed to an appropriate temperature by holding the bottle under running tap water or placing the bottle in a container of cold water. Ensure the cooling water is below the cap and does not touch the teat.

  5. Test the temperature

    To prevent scalding the baby's mouth, test the temperature of the formula feed on the inner side of your wrist before feeding. Repeat cooling until the feed is lukewarm.

    Key facts

    Consume the prepared formula feed within 2 hours to reduce the risk of infection.

How to store a prepared infant formula feed?

  • It is best to make up a fresh feed each time your baby needs one, and to consume it immediately.
  • If you have to make up a feed in advance, cool the feed immediately after it is prepared and store it in the fridge at temperature of 4℃ or below.
  • Throw away the refrigerated feeds if they are not used within 24 hours.

How to rewarm a feed?

  • Rewarm a refrigerated feed no more than 15 minutes. Rewarm the feed by placing the bottle in a container of warm water. Make sure the water level does not touch the cap or the teat. Swirl the bottle occasionally to ensure the milk warms up evenly.
  • Follow the manufacturer's instructions if you use a bottle warmer.
  • Never rewarm leftover feeds.

Key facts

  • A formula feed should be consumed within 2 hours of rewarming. Throw it away if it is not consumed within that time.
  • Never use a microwave oven to rewarm refrigerated formula feeds. Microwave heats the feeds unevenly. This can scald the baby.

Q. How can I prepare formula feed away from home?

  • If you need to feed your baby away from home, you can choose sterile ready-to-feed liquid infant formula. If you choose to make up feeds with powdered infant formula away from home, pay special attention to the procedures and ensure all feeding equipment are sterilised.
  • As sterilisation needs time, parents are advised to prepare in advance sterilised feeding bottles and containers. Before going out, place the powdered infant formula in a dry container. Pour the water that has just been boiled into an insulated vacuum flask and screw the cap tightly. This helps to keep the temperature of water at 70℃ or above that is necessary for making up a formula feed.

Q. Is it OK to prepare the formula feed first before we go out?

  • It is safest to give your baby a freshly prepared feed every time your baby needs it. If you have to carry a pre-prepared feed, cool the feed immediately after it is made up and refrigerate it at a temperature of 4℃ or below. Shortly before you leave home, put the prepared feed in an insulated cool bag with an ice pack for delivery. Remember that made-up formula taken out from the fridge must be consumed within two hours.

When should I feed my baby?

Babies show hunger and fullness cues regardless of whether they are breastfed or bottle fed.

  • When hungry, your baby will search for a feed. Below are some early hunger cues:
    • Waking up and moving
    • Licking their lips
    • Turning their head to search with an open mouth
  • If not fed, they will progress to showing mid-hunger cues
    • Sucking their hand or fist
    • Moving their arms and legs
  • Crying and agitation are usually late hunger cues. Babies are "extremely hungry" by that time. However, babies may also cry for other reasons.

How should I respond to my baby's feeding needs?

  1. Observe and respond to your baby's cues: Feed your baby when they show "early hunger cues", follow their pace during feeds, and stop feeding upon noticing "fullness cues".
  2. Stay close to your baby: Hold your baby close when feeding, look into their eyes, and gently talk to them. Skin-to-skin contact and responsiveness can stabilise your baby's mood, and help brain development.
  3. Do it yourself: Parents should try to feed their baby if possible.
  4. Adopt a consistent way of feeding: Avoid too many different carers. This helps your baby adjust.

How do I feed my baby?

(Bottle feeding video)

Follow your baby's lead during feeding. Let them control the pace and decide how much they feed.

  1. Wash your hands before you feed your baby and help put on the bib. Get yourself into a comfortable position with back support. You may tuck a pillow under your elbow for extra support.
    • Try to switch the side you are holding your baby during feeding to encourage eye stimulation from both sides.
  2. Hold your baby close in a semi-upright position with their head and neck resting on your elbow so they can breathe and swallow comfortably.
  3. Let your baby see the feeding bottle. Softly brush the teat against their upper lip to invite them to open the mouth. Gently insert the teat into the mouth. If the baby does not open their mouth, do not force the teat inside.
  4. Hold the bottle horizontally or slightly tipped to ensure the tip of the teat is filled with milk. This can prevent the milk from pouring out too quickly. Thus, your baby can control the milk flow through active sucking, and can also avoid overfeeding.
  5. Observe your baby. If they splay their fingers and toes, stop sucking, turn their head away, push the bottle away, or milk spills from their mouth - give your baby a feeding break by withdrawing the teat. Do not rush them by tapping or shaking the bottle.

    If your baby would like to continue, they will draw the teat in. If they let the teat go, you may burp them. Offer the bottle again after burping.

  6. Learn the fullness cues of your baby. Let them decide how much to have at each feeding. Stop feeding when your baby shows signs of being full, such as if they:
    • close their mouth
    • suck slower or stop sucking
    • let go of the teat
    • push away the feeding bottle
    • arch the back and turn head away
    • relax the body and sleep

Important Notes

  • Do not add or mix any food or medicine into the infant formula.
  • Never prop up the bottle or leave your baby alone during a feeding. This puts them at risk of choking and suffocation.
  • Observe your baby's breathing and their effort in sucking. Babies may need a lot of effort to suck if the hole of the teat is too small. Check the teat type or size if needed.
  • Do not force your baby to complete the bottle. Throw away the leftover formula milk and/or expressed breastmilk.
  • Do not let your baby sleep with a bottle as they will start associating bottles with sleep, and will have difficulty dozing off without it. This can also cause cavities when they start teething.

How do I burp my baby?

(Baby burping video)

Burp your baby after feeding to expel the air they have swallowed during feeding.

  • Burp your baby after feeding or when they take a short break during the feed
  • You can burp them in the following ways:
    • Hold your baby upright on your shoulder. Gently pat or rub their back.
    • Sit them on your lap. Support the head and chest. Gently pat or rub their back.

What should I do if my baby spits up after feeding?

Many newborns spit up a little after feeding, during burping, or when lying down because their digestive tracts are immature.

The following helps decrease these spitting episodes:

  • Feed your baby when they show early hunger cues. This helps them stay calm and swallow less air during feeding.
  • Keep the tip of the teat filled with milk during feeding.
  • Avoid overfeeding. Stop feeding when the baby shows cues of getting full.
  • After feeding or burping, keep your baby in an upright position for 10 to 20 minutes. You can either hold them or sit them on your lap.
  • If spitting up does not improve, consult your doctor.

How much milk does a baby need in a day?

Babies adjust the amount of milk they take to meet their needs for growth and development. Their appetite changes from meal to meal and day to day. Let your baby guide you when and how much they need.

  • Every baby is unique. Some babies need small frequent feedings, while some need to be fed less frequently but take more milk each time.
  • On the first few days after birth, babies take only small amount of infant formula at a time as their stomach is quite small. They usually need to be fed every 2 to 3 hours as they wake up. In the following few weeks, they may take around 60 to 90 ml every 3 to 4 hours. Sometimes they may need to be fed more frequently too, so follow their feeding cues.
  • One- to two-month-old babies usually settle into their own regular feeding patterns. From the age of two to six months, some babies adjust to a regular night and day pattern. They sleep for 5 to 6 hours at night and consume a greater quantity when they wake up in the early morning.
  • The amount of formula milk needed daily varies from baby to baby. Here is a reference for healthy babies in the first few months 7：
    Age Daily consumption of formula milk
    1 month About 550 – 970 ml
    2 to 5 months About 630 – 1110 ml
  • Babies know how much they need for their growth and body needs. Some babies may have a bigger appetite for a few days and eat less in the following days. If they are playful and gaining weight well, a change in appetite should not cause a concern.
  • Do not try to make your baby finish the bottle. Babies' appetite changes from day to day. Follow their cues and let them decide how much they need. Forcing your baby to finish a feed can be a stressful experience and make them take more than they need.

7Leung, S.S.F., Lui, S. & Davies, D.P. (1988). A better guideline on milk requirements for babies below 6 months. Australian Paediatric Journal, 24, 186-190.

Is my baby getting enough to eat?

Your baby is well fed when they have the following signs:

Wet nappies:

  • Have 1 to 2 wet nappies each day on the first two days after birth.
  • Have at least 3 wet nappies each day on the 3rd and 4th days.
  • From the 5th day onwards, have at least 5 to 6 heavy nappies (about the weight of 3 tablespoons of water in each nappy) and the urine is transparent to pale yellow.

Baby's stool:

  • Changes from passing meconium to yellowish stool in the first 5 days.
  • Changes texture from loose, pasty, to seedy gradually.

Baby's weight:

  • In the first few days after birth, it is normal for your baby to lose a bit of weight.
  • By the first to second week, your baby regains birth weight and then puts on weight steadily.
  • In the first 2 months, majority of infants gain 0.5 kg or more in weight per month on average.

If you have any queries concerning bottle feeding, please consult your doctor or nurse.

For more health information, please visit the Family Health Service webpage: www.fhs.gov.hk or call the 24-hour Information Hotline: 2112 9900.

Key Points for Bottle Feeding

World Health Organization recommends that babies should be exclusively breastfed in the first six months. At about six months old, babies should be given nutritious solid foods and continue breastfeeding up to the age of two years or above. If parents cannot or have chosen not to breastfeed their baby, feeding the baby with infant formula is the only alternative during their first few months.

Choosing Infant Formula

  • Infant formula ("Stage 1 formula") is suitable for newborns and babies below 12 months of age.
  • Follow-on formula ("Stage 2 formula") is not suitable for infants below 6 months of age. Switching to follow-on formula is not necessary after 6 months old.

Preparing the Infant Formula Feed

  • Feeding bottles, teats and other equipment must be cleaned and sterilised.
  • Measure the amount of water and powdered infant formula accurately according to the instructions on the package when making up the feed.
  • Put the water in the bottle before adding the powdered infant formula. The temperature of water must be at 70°C or above.
  • Offer freshly prepared infant formula feeds to babies. The formula feed should be consumed within 2 hours after being prepared.

Feeding the baby

  • Test the milk temperature.
  • Support the baby in a semi-upright posture and hold them during feeding.
  • Feed the baby according to their feeding cues. Do not force-feed.
  • Discard any leftover milk.