How Long Can Breast Milk Be Kept At Room Temperature?

breast milk

Breast milk fed through the natural process provides your child with a fresh, bacteria-free milk. However, it’s important to consider proper preservation methods in case you are away and still want to feed your baby with the healthiest food. There are different preservation methods, but choosing an effective one is key. Experts suggest breast milk kept at room temperature for about eight hours is still safe for consumption, but leaving it unrefrigerated for more than four hours can affect the level of nutrients. 

Breast Milk is able to terminate viruses and bacteria, so it remains safe for a few hours before spoilage. One effective method of preservation is freezing. It preserves milk nutrients longer than other procedures. But how long can frozen milk last? Find out other alternative methods and their safe time duration.

How To Effectively Store Breast Milk

After collection, you can either store breast milk at room temperature, keep it refrigerated, freeze it, or use insulated and closed cooler packs. These methods help in preservation for reasonable amounts of time before consumption.

Preserving breast milk, avoid using plastic containers that may contain a chemical called Bisphenol A (BPA). This is usually contained in recycled plastics of a higher range of about 7. Alternatively, use hard plastics free of BPA or a neat glass bottle. You can also opt for thick plastic storage bags designed specifically for Breast Milk preservation, and they help in safe storage during freezing.  Most mothers prefer baby bottles made with polycarbonate and coated with BPA to prevent tarnishing when sterilized.

The Growth Of Bacteria In Breast Milk

Unlike many other foods, breast milk contains antibacterial characteristics that make it last longer and stay healthy. But there are specified durations before consumption, depending on different storage methods. It may not be dangerous for consumption after required periods, but babies may reject it because of its foul smell and taste.

Temperature is the major factor that affects breast milk preservation. It determines how long before bacteria start to form on the surface. Breast Milk kept under a hot room temperature for up to eight hours or more can be unsafe. A higher temperature causes bacteria to grow and act faster. Using a refrigerator is mostly effective for proper storage, but cooler packs with ice can also be useful. 

Once breast milk has been pumped and stored in required containers, a label according to the time and day collected. This is important to track and easily identify spoilt milk. After this procedure is completed, store in the heart of the refrigerator. Choose the coolest part of the freezer for more cooling effect; avoid placing it close to the refrigerator door, as it will be subjected to a gust of hot or warm air when opened.

Also Read:  How to Warm Breast Milk From Fridge : Do's & Don'ts

Don’t forget to portion breast milk into separate containers, according to the quantity needed for one feed. This is necessary to reduce the number of times it is exposed to warm air.

How Long Is It Safe?

Breast Milk is generally endorsed because it contains essential nutrients like carbohydrate, protein, and fats plus other constituents that prevents it from easy spoilage. But how should you store it to keep it fresh?

Various means of preserving breast milk have different times before spoilage. Here is their duration:

  • Room temperature: Preserving breast milk without any medium requires 4 hours before bacterial action. Moderately warm room temperature preserves it for up to six hours. A safe room temperature for breast milk preservation is 77 degrees Fahrenheit, after which its quality is reduced.
  • Insulated cooler packs: storing breast milk in an enclosed cooler packed with ice is an effective storage alternative for refrigerators. Place the breast milk container into an enclosed and insulated pack and surround it with ice as a cooling medium. Freshly collected breast milk is considered healthy for up to 24 hours using this preservation method. After this period, it should be refrigerated or frozen.
  • Freezer:  Place milk inside a freezer compartment if you’re not using it within four days. Freshly collected breast milk should be preserved at the back of the freezer for only about 12 months. However, the duration is dependent on the type of freezer compressor. So it is advisable to use within six months from the collection date, as more nutrients are lost when stored for a longer period. In other words, the shorter you preserve breast milk, the lower the nutrients loss.
  • Refrigerator: A refrigerator can store and preserve breast milk ideally for only about 3 to 4 days. Eight days’ storage is also safe depending on the refrigerator temperature. Avoid re-freezing breast milk after it was previously frozen for 24 hours.

How Does Spoiled Breast Milk Look?

Breast milk will lose its fresh nature when kept out in the open or even in the refrigerator when left longer than it should, so it’s important to identify spoiled milk before feeding it to an infant. Not properly sealed containers or three-day-old breast milk is not enough reason to tag it as spoilt. Here are signs to look out for in spoilt breast milk:


Awkward breast milk taste doesn’t represent spoiled milk. Sometimes, the taste of the milk may be affected by what you consume. The taste of your breast milk depends on the type of food or drugs ingested. Try eating plenty of fruits, vegetables, and whole-grain meals like carrots, potatoes, pickles, beans, or oats to produce tasty milk.

The storage mode can also affect breast milk, so tasting is required regardless of how it was stored. Sour, stale, or rotten taste indicates spoilage – The taste of bad breast milk is nowhere different from spoilt cow milk.


Lipase is the main nutrient that breaks down fat in milk, and it also helps babies digest milk easily. Once breast milk is left to stand, lipase breaks down fat faster, and if left longer without adequate storage method, it produces a foul smell.  A soapy smell indicates the milk contains a high level of lipase enzyme. Spicy foods, caffeine, alcohol, or Fish oil consumption in excess can make your breast milk smell bad, even before the required spoilage time. A smelly refrigerator can also affect the smell.

Also Read:  Increasing Breast Milk Supply with Fenugreek Seeds


When breast milk has been collected and stored, some of the constituents’ settles. Agitating it should produce a homogenous mixture. But continuous swirling without mixing indicates spoiled milk – discard it. Normal breast milk appears yellow, off-white, or slightly orange, depending on what you eat. White and watery breast milk is often tagged as spoilt.

Is It Safe To Feed My Baby Leftover Breast Milk?

One major problem of feeding a baby leftover milk is the increased action of bacteria from his mouth on the milk bottle. The bacteria in the baby’s mouth acts on the milk and contaminates it. Some mothers who have an issue with the level of milk production can opt for properly refrigerated leftovers. But If there’s no valid reason to feed babies leftover milk, avoid it! 

Working nursing mothers that rely on leftover milk should endeavor to refrigerate in small and portioned quantities.

Is Leftover Milk Harmful?

Feeding your baby leftovers may be unsafe for them due to the high bacteria content; Leftover breast milk contains minimal or no nutrients, so it’s not advisable to feed them leftovers, but there’s no theory or claim that leftover milk is harmful. It may cause an increase in their bowel movement, but it likely won’t hurt them.

Any Alternate Use Before I Discard Leftovers?

Totally! There are several alternative beneficial uses of leftover breast milk, but it’s important to consult a doctor for medical advice before trying these home remedies. It can be used to:

  • Ease eczema if your baby has sensitive skin that is prone to this infection.
  • Treat acne on their skin.
  • Stop the spread of diaper rash and reduce redness and irritation.
  • Soothe and relieve sore nipples.
  • Treat sunburn and insect bites.
  • Fertilize plants.
  • Ease ear infection in babies
  • Freeze and use to ease pain accompanied with teething.
  • Make solid baby foods that have a familiar taste.


Milk stored at room temperature is prone to high lipase action, causing it to produce a foul smell; refrigerated or frozen breast milk stops and restricts further action of bacteria. To recognize spoilt breast milk, it’s important to know how normal breast milk looks. Storing milk at room temperature is not ideal because it can only last a few hours before spoilage; freezing is better because the required nutrients are still retained even after a long period. Slightly orange, off-white, cream or tinted blue milk are normal breast milk color.  

Avoid feeding your child with white and fluid-like milk, as it may affect their well-being; do not reheat previously frozen milk. Frozen milk is the most effective form of milk preservation with a shelf-life of six to twelve months.

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