How Long Can Formula Stay Out (And Why)?

Exact Answer: 2 Hours

Formula or Infant Formula is a substitute that can be used to feed a baby in the absence of the natural mother’s milk. It can be used in case a mother is unable to breastfeed. Since a newborn needs its mother’s breastmilk to get all the nutrients to grow, using alternatives like infant formula can be a good option.

Baby formula is a food product for babies, and hence it tends to spoil sometimes. It is necessary to know how long the formula will last since it affects the quality. It also impacts the health of the baby.

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How Long Can Formula Stay Out?

The shelf life of the formula will depend on different factors. It includes the type of formula that is being used. Since there are different types of formula available in the market like Cow milk protein-based formula, soy-based formula, or even protein hydrolysate formula. It also depends if the formula is kept in the box or kept out prepared.

Each type has different ingredients and hence has a different shelf life. Usually, the formula in the box can last till a month. When it comes to the formula being prepared and kept out, the shelf life of the formula is low. Once a baby formula is prepared, a chemical reaction starts happening. It will eventually ruin the formula.

If the baby formula is prepared, it should be kept in an air-tight container in the refrigerator. If it is to be kept out at room temperature, then it is imminent that it s used within two hours of preparation. 

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If the prepared formula is fed to the baby, the remaining formula needs to be fed within an hour as it will spoil after an hour.

Storage conditionShelf life of the prepared formula
Freshly prepared baby formulaWithin two hours of preparation
The baby formula once fed to the babyRemaining to be used within an hour

Why Can Formula Stay Out For So Long?

Baby formula is in general made from mixing many ingredients to make it nutritional. Everything that is added has its expiration date. Once any food is prepared, the heat or the mixing can start a chemical process. After some time, the chemical process leads to the growth of bacteria. 

The case is similar when it comes to the simple preparation of baby formula too. The baby formula once prepared is prone to getting spoiled fast. There are many reasons behind the low shelf life of the formula. A few of the reasons are as below:

  • The primary factor determining the shelf life of the formula is the brand. The different brand uses a varied list of ingredients that cause the difference in the shelf life. The longest time for which the formula is good to use after mixing is about two hours. But there can be certain brands that will only have a shelf life of about an hour after mixing.
  • Another factor that can decide the shelf life is if it is fresh or has been already fed to the baby. Once the prepared baby formula is fed, the shelf life is reduced considerably. The reason behind that is that once the baby consumes the formula, the baby’s saliva will mix with the remaining formula. It will speed up the chemical process. The baby formula will only last for about an hour or even less.
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Infant formula contains all the necessary nutrients that will be healthy for the baby. The baby formula can also be prepared and kept in the refrigerator. But even that will increase the shelf life of the formula by only a couple of hours.

The maximum time for which the baby formula can be kept in the refrigerator is about four hours. After which it will start spoiling, and will become unfit for consumption.

The baby formula container, if unopened, can last for the time that it is mentioned on the box. The formula is not to be used past its expiration date to avoid ill effects. Once the container is opened, it should be used within a month or as soon as possible. The opened box is supposed to be kept in a dry place to use to the full extent.


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Hi! I'm Nidhi.

Here at the EHL, it's all about delicious, easy recipes for casual entertaining. So come and join me at the beach, relax and enjoy the food.

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