How Many Times Can You Reheat Formula?

Are you wondering how many times can you reheat formula milk?

We’ve all been there. You make the baby a fresh bottle of formula when the phone rings, and suddenly fifteen minutes have passed and the bottle’s gone cold.

Do you make another new bottle, or can you safely reheat the one you made? Keep reading to learn more about food safety when it comes to baby formula.

How can you safely store formula?

According to the CDC, baby formula that’s been pre-prepared and left at room temperature can spoil starting two hours after making it.

If after two hours you haven’t used the prepared formula, then you can safely store it in the fridge for use within 24 hours.

How Many Times Can You Reheat Formula?

Remember, always throw away any formula leftover in the bottle when you’ve finished feeding your baby.

The mixture of your baby’s saliva with the formula can cause harmful bacteria to grow in your baby’s bottle. This is why it’s extremely important to ensure that all bottles and accessories are clean and sanitized before use.

What do the experts say?

The FDA states, “it’s not a good idea to repeatedly reheat formula because lots of nutrients can be lost.”

The USDA adds that you should “Never use a microwave oven to heat bottles of breast milk or infant formula. They may explode or the milk may get too hot”

Here is the FDA’s recommendations:


  • Don’t make more formula than you will need. Formula can become contaminated during preparation. If a large quantity of formula is prepared and not properly refrigerated, bacteria can multiply to very large numbers. The more bacteria there are, the greater the chances for foodborne illness. Preparing formula in smaller quantities on an as-needed basis greatly reduces the possibility of contamination. If using powder, reconstitute immediately before feeding. If using liquid concentrates or ready-to-feed products, follow label instructions provided by the manufacturer.
  • Don’t put a bottle back in the refrigerator if the baby doesn’t finish it. Harmful bacteria from a baby’s mouth can be introduced into the bottle during feeding; they can grow and multiply even after refrigeration (some bacteria can grow at refrigerator temperatures) and reheating. The temperature that’s needed to kill harmful bacteria is extremely high for consumption by a baby. Also, it’s not a good idea to repeatedly reheat formula because lots of nutrients can be lost.
  • Don’t feed a baby from a jar of baby food and then put it in the refrigerator. Saliva on the spoon may contaminate the remaining food. Instead, put a serving size on a dish. Refrigerate the food remaining in the jar. Throw away the food in the serving dish that’s not eaten.

How many times can you reheat formula?

If your baby drank the formula, you should NOT reheat it. This is because baby’s saliva mixed with the formula and can cause bacteria to grow.

Reheating encourages bacteria to grow (in as little as 30 mins) so even handling the bottle and then reheating can be a problem.

How can I reheat formula that has already been prepared?

You know that formula should only be reheated one time after it has already been prepared and heated, you might be wondering how to re-warm it.

Here’s how you can re-warm pre-prepared, stored baby formula:

  • Remove the prepared formula from the refrigerator immediately before use.
  • Place the container in shallow, heated water for up to 15 minutes, or use a bottle warmer.
  • After 2 hours at room temperature, throw away any un-used infant formula.

Now that you know how to better prepare formula for baby, feel free to check out one of our other articles for more information on how to properly re-heat food for you and the rest of your family.

Can I make my infant’s formula taste better?

It is not recommended that you introduce any additional ingredients into your baby’s formula unless otherwise instructed by your health care professional.