Baby food formula ratio

How to Make a Baby Bottle: Storage and More

Guidelines on how to mix and store baby formula for your little one


Whether you’re feeding your baby with formula only or are breastfeeding and supplementing with formula, it’s important to know the basics of formula preparation and storage. This not only saves time, but also helps keep your baby happy and healthy.

With all the mixing, storing, and warming dos and don’ts, there’s a lot to remember. We get it. And we’re here to help. If you have more questions, you can also talk to your doctor.

Choosing the right formula: 3 basic steps

To start with, here are 3 easy steps that will help you choose the right formula, plus a few things to keep in mind before you prepare it.

Step 1: Choose the right formula for your baby. If you’re not sure what formula is best, talk with your pediatrician for advice. Use our Formula Finder to get tailored suggestions.

Step 2: Choose the type of formula that works best for you: powder, ready to feed, or concentrated liquid.

Tip: Use powder or concentrated liquid for everyday use and ready to feed for convenience when traveling.

Step 3: Read all the information below before making your first bottle. We hope this will answer any questions that may come up along the way.

How to mix and prepare Similac

® powder baby formula

Preparing Similac powdered formula is simple, but it’s still important to carefully follow the directions. Your baby's health depends on it. Proper formula preparation is important in order for your child to receive the necessary nutrition.

Formula-to-water ratio: 1 level scoop of formula (not packed down) per 2 fl oz of water. Be careful not to add too much water. Watered-down formula is not recommended, as it dilutes essential nutrients and can affect your child's nutrition.

Reminder: Powdered infant formula is not sterile and should not be fed to premature infants or infants with immune problems unless directed and supervised by your doctor.

Preparing formula with boiled water

Ask your baby’s doctor if you need to use cooled, boiled water for mixing and if you need to boil (sterilize) bottles, nipples, and rings before use. If you choose to boil, follow these steps:

1. Bring water to a rolling boil for 1 minute, then turn off the heat. Overboiling can increase the concentration of impurities.

2. Let the water cool to room temperature before adding formula. Making formula with boiling water can cause clumping and decrease the nutritional value.

3. Before feeding, sprinkle a few drops on the inside of your wrist to make sure it is not too hot.

4. Feed or refrigerate the prepared formula.

Note: If you are concerned about lead or other harmful substances in your water, talk to your healthcare professional before making formula with tap water. Bottled or filtered water can contain bacteria and should still be boiled.

Mixing Tips for Similac Powdered Formula

Single bottle instructions

1. Wash your hands thoroughly with soap and warm water.

2. Measure and pour desired amount of water into the baby bottle.

3. Add unpacked, level scoop(s) of powder formula to the bottle as directed. Return dry scoop to can. (1 scoop of formula per 2 fl oz of water.)

4. Put the cap on the bottle and shake.

Tip: Moving your wrist in a twisting motion helps powder formula mix more quickly and more thoroughly.

5. Feed or store immediately in refrigerator.

Multiple bottle instructions*

1. Measure 23 fl oz of water using a liquid measuring cup.

(NOTE: If using Similac NeoSure powder, use 21 fl oz of water instead of 23 fl oz of water for standard caloric density.)

(NOTE: If using Pure Bliss™ by Similac® powder, use 24 fl oz of water instead of 23 fl oz of water for standard caloric density.)

2. Add 1 cup (100 g) of powder, unpacked and level, using a household measuring cup for dry ingredients.

3. Add powder to water and mix well.

4. Pour prepared formula into individual feeding bottles.

5. Put the cap on and store immediately in the refrigerator. Feed within 24 hours.

Similac® For Spit-Up mixing tips

Similac For Spit-Up formula contains rice starch. This means that compared to other Similac powdered formulas, it mixes a little more slowly with water. This is true of any formula that contains rice starch.

Rice starch also makes Similac For Spit-Up look more "grainy" than other Similac formulas. What you are seeing is tiny grains of starch and not a product defect.

Try these tips to help prevent clogged nipples:

  • Mix the powder and water, then wait 2 minutes
  • Gently swirl, or agitate, the formula in the bottle before feeding
  • Or, mix the formula in a separate container, and then pour into a bottle to feed

What temperature should baby formula be?

Formula does not need to be warmed. But, if you do want to feed warmed formula, do not microwave it. This can cause "hot spots" that could burn your baby. Instead, set the filled bottle in a bowl of warm (not boiling) water. You can also hold the bottle under warm tap water. Sprinkle a few drops of formula on the inside of your wrist to make sure it’s not too hot.

How to prepare Similac Ready-to-Feed formula (or how to make formula bottles in advance)

Preparing Similac Ready-to-Feed formula is easy. You don’t need to mix or measure anything. Just shake the bottle well before opening, twist off the cap, and pour into a baby bottle. Or, if you’re using a 2-fl-oz Ready-to-Feed bottle, just twist on a nipple and ring. This way, there’s no need to make anything in advance when you’re going out.

Baby formula storage guidelines for Similac products

Similac powder formula storage

  • Once opened, store powder formula in a sealed container in a cool, dry place
  • Once mixed, feed immediately or refrigerate in a sealed container; use within 24 hours
  • Do not freeze mixed formula—this can cause the protein and fat to separate
  • Do not store unmixed powder in the refrigerator
  • Avoid extreme temperatures
  • Use the product within 1 month                            

Similac Ready-to-Feed formula storage

  • Store unopened bottles at room temperature; avoid extreme temperatures
  • Store in carton until ready to use
  • 32-fl-oz bottles: Once opened, store immediately in the refrigerator for up to 3 days (72 hours) or 2 days (48 hours) when opening Alimentum. If poured into individual baby bottles, store immediately in the refrigerator and feed within 48 hours
  • 2-fl-oz and 8-fl-oz nipple-ready bottles: Once opened, use or store immediately in the refrigerator and feed within 48 hours
  •  Do not reuse bottles
  •  Protect bottles from light

See the product labels for more instructions.

How long is formula safe to use after being mixed or prepared?

Formula made from powder must be used within 24 hours. Ready-to-Feed formulas must be used within 48 to 72 hours after opening according to label directions. Once powder has been mixed with water or Ready-to-Feed bottles have been opened, they must be stored in the refrigerator until feeding.

Check the date

Never feed expired formula to your baby or use formula from a dented container.

Now that you know how to make the perfect bottle for your little one, visit Formula Feeding Basics for helpful feeding tips.

* Makes approximately 26 fl oz of prepared formula.
For most accurate results, powder should be weighed on a scale that reads in grams.
Avoid vigorous shaking right before feeding, which can cause air bubbles that can lead to gas in your baby.

Join Similac® Rewards for up to $400* in benefits and support throughout your journey.
* Offers may vary.

Sign Up

Formula Feeding FAQs: Starting Solids and Milk (for Parents)

Whether you plan to formula feed your baby from the start, want to supplement your breast milk with formula, or are switching from breast milk to formula, you probably have questions.

Here are answers to some common questions about formula feeding.

When Can My Baby Try Solid Foods?

Doctors recommend waiting until your baby is about 6 months old to start solid foods. Some babies may be ready for solids sooner than 6 months, but wait until your baby is at least 4 months old.

Babies who are ready to eat solids foods:

  • are interested in foods (for example, they may watch others eat, reach for food, and open their mouths when food is near)
  • hold up their heads well, and sit up with little or no help
  • don't push food of their mouth (which is a natural tongue reflex that disappears when babies are 4–6 months old)
  • usually weigh twice their birth weight, or close to it

Talk to your doctor about the right time to start solid foods.

How Do I Introduce Solid Foods?

When the time is right, start with a single-grain, iron-fortified baby cereal. Start with 1 or 2 tablespoons of cereal mixed with breast milk, formula, or water. Feed your baby with a small baby spoon. Don’t add cereal to a baby's bottle unless your doctor recommends it.

When your baby gets the hang of eating the first food, introduce other foods from all food groups, such as puréed meats, fruits, vegetables, grains, beans, and yogurt. Wait a few days between introducing new foods to make sure your baby doesn't have an allergic reaction.

You can include foods that are more likely to cause allergies — such as peanuts, eggs, cow’s milk, seafood, nuts, wheat, and soy — among the foods you introduce to your infant. Waiting to start these foods does not prevent food allergies.

Talk to your doctor before giving foods that contain peanuts if your baby has severe eczema or an egg allergy, as these conditions make an allergy to peanuts more likely. Eating peanut-containing foods early on may lower a child’s chances of developing a peanut allergy. But your doctor will need to decide if you can give peanuts to your baby, and the safest way to do it. Usually, this requires allergy tests.

Should We Avoid Some Foods?

Yes, don’t give your baby:

  • foods with added sugars or no-calorie sweeteners
  • high-sodium foods
  • honey until after the first birthday. It can cause botulism in babies.
  • unpasteurized juice, milk, yogurt, or cheese
  • regular cow's milk or soy beverages instead of breast milk or formula before 12 months. It’s OK to offer pasteurized yogurt and cheese.
  • foods that may cause choking, such as hot dogs, raw carrots, grapes, popcorn, and nuts

Always supervise your child when eating. Make sure your child is sitting up in high chair or other safe place.

When Can My Baby Have Cow's Milk?

Before their first birthday, babies still need the nutrients in breast milk or formula. But after that, they’re ready to switch to cow's milk.

Most kids under age 2 should drink whole milk. If a toddler is overweight or there is a family history of obesity, high cholesterol, or heart problems, your doctor might recommend switching to reduced fat (2%) milk.

If your child can’t drink cow’s milk, choose an unsweetened soy beverage fortified with calcium and vitamin D. Other milk alternatives, like almond, oat, rice, or coconut milk, have less protein and may not be fortified.

How Do We Switch to Cow’s Milk?

You can switch your baby from formula to whole milk by replace bottles of formula with bottles — or sippy cups — of milk. By 1 year old, your baby should be eating a variety of solid foods and drinking about 16 to 24 ounces (480–720 milliliters) of milk per day.

When Can I Start Giving My Baby Water and Other Drinks?

In their first 6 months, healthy babies drinking enough formula usually don't need extra water. Once your baby is eating solid foods, you can offer a small amount of water between feedings, up to 4–8 ounces a day. 

Water that has fluoride helps prevent tooth decay. If your water does not have fluoride, talk to your doctor or dentist about fluoride drops.

Do not give juice to babies younger than 12 months. After your child’s first birthday, limit 100% fruit juice to no more than 4 ounces a day. Always serve juice in a cup, not in a bottle. Don’t give your child sugar-sweetened beverages, including soda, juice drinks, sports drinks, and flavored milks.

Reviewed by: Mary L. Gavin, MD

Date reviewed: November 2021

Composition of infant formula

Breastfeeding is the best way to provide your baby with ideal nutrition for normal growth and development.

Dry initial milk formula adapted by Valio Baby 1 NutriValio for feeding children from birth to 6 months Read more

Mother's milk is a unique biological and emotional basis for the baby, being a natural type of food, fully adapted to the digestive functions of the baby.

However, for objective reasons, many mothers have to transfer their children to formula milk. And then the question arises, how to choose a milk formula, the composition of which is as close as possible to the composition of mother's milk. What vitamins and nutrients should be in infant formula?

The compositions of modern infant formulas are developed in strict accordance with the recommendations of the World Health Organization*. Any parent will find their reflection on every package of baby food, since all manufacturers of infant formula must ensure that there are labels on the packaging detailing all the necessary information about the composition of the product, the ingredients used and storage conditions.

When choosing a formula for children of the first year of life, one of the most important criteria should be the compliance of the composition of the mixture with the age-related metabolic capabilities of the child. It must have a balanced complex of components, contain a certain amount of calcium, phosphorus, iron, sugars, vitamins, proteins, fats and carbohydrates.

Protein - 1.2 - 1.6 g / 100 ml (mother's milk contains - 0.9 - 1.3 g)

For better digestibility of the milk formula, manufacturers adapt the protein by adding demineralized whey to the composition of cow's milk. Such proteins help bring the amino acid composition of the formula closer to the amino acid composition of mother's milk. The content of casein proteins in women's milk does not exceed 35% of the total, in cow's these proteins 80% of the total percentage of proteins. Therefore, in baby food, the balance of the ratio of whey proteins and casein in the proportion of 60:35 - 60:40 is important. If this ratio is not indicated on the package, you can independently calculate it by the amount of casein and whey proteins contained in the mixture.

Fats - 3.2 - 3.7 g / 100 ml (mother's milk contains - 3.5 g)

Fats provide from 30 to 55% of the daily energy requirement. To make up for the lack of fat, mixture manufacturers add vegetable oils to the food. They are the main source of polyunsaturated fatty acids involved in the development of the brain, vision and enhance immunity. As a rule, the composition of baby food includes: coconut, soy, sunflower and corn oils. They are listed on the label as linoleic and linolenic acids. The optimal combination of these acids in baby food is 7:1, respectively.

The combination of vegetable fats (coconut, rapeseed and sunflower oils) and milk fat allows you to increase the content of PUFAs of the Omega 3 and Omega 6 families and bring the fatty acid composition of Valio Baby® milk formulas closer to that of human milk.

Carbohydrates - 7.0 - 7.5 (mother's milk contains - 7 - 7.5 g)

Often, it is carbohydrates that determine the tolerability of infant formula. The main component of the carbohydrate component is lactose. Breast milk is significantly superior to cow's milk in terms of the amount of carbohydrates. In addition to lactose, starch, sucrose and maltodextrin can be found in the composition of the carbohydrate component of infant formula. A more physiological component for a baby in the first months of life is lactose. It promotes the absorption of magnesium, manganese and calcium, and also stimulates the growth of bifidobacteria in the intestines of the child.

It is also important to pay attention to the content or absence of starch and maltodextrin in the carbohydrate composition of baby milk food. Both of these substances make the mixture viscous, as a result of which it passes more slowly through the baby's gastrointestinal tract, allowing you to increase the periods between feedings. However, it is highly undesirable that these components be present in mixtures intended for feeding children under 12 months of age. Ideally, the mixture should contain only lactose.

Prebiotics and probiotics

They influence the development of beneficial intestinal microflora, and also facilitate digestion, contribute to the formation of regular stools in the baby and are responsible for strengthening the immune system. Formula manufacturers do not always add prebiotics and probiotics to their formulas. However, it is better to give preference to infant formulas, in which they are included.

Vitamins and minerals

When formulating milk formulas, their vitamin and mineral composition is taken into account. Quantitatively contained in mixtures of vitamins and minerals should be 15-20% higher than their presence in breast milk. This rate is due to the fact that vitamins are absorbed worse from mixtures than from mother's milk. In a complete mixture, vitamins and minerals are always optimally balanced, because the lack of even one important component can adversely affect the growth and development of the child. In the baby's diet, the presence of water- and fat-soluble vitamins of groups A, B, C, D, E, K is mandatory. In addition, infant formula should be enriched with calcium, zinc, copper, selenium, iron, iodine and potassium. Breastfed babies receive these micro and macro elements in sufficient quantities with mother's milk.

Amino acids

Taurine is one of the most important amino acids that milk formulas should be enriched with, as this amino acid is necessary for the development of the brain and retina. Taurine is not found in cow's milk. Therefore, mixtures should contain 5-7 mg of taurine per 100 ml; in breast milk, these figures are closer to 5 mg / 100 ml. It is important to remember that the body begins to synthesize this amino acid only after 1. 5 months.

Lutein is an antioxidant that provides protection to the retina and stimulates the development of memory and learning processes. Babies can get this element only from women's milk or infant formula enriched with it.

In addition to important and irreplaceable elements, some manufacturers often add ingredients to infant formulas that should not be there: sugar, soy, starch and palm oil.


A rational choice of infant formula should first of all take into account the age needs of the baby, his state of health and, of course, the presence of all vital components for harmonious growth and development. Also check out our experts' helpful resource on infant formula storage.

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