Have you been wondering how long your breast milk will be good for if left at room temperature? Or how long you can keep it in the fridge before you have to freeze or use it? The information below, sourced from La Leche League International explains safe storage time frames, temperatures and storage methods.
According to La Leche League International, Human milk actually has anti-bacterial properties that help it to stay fresh.
This information is based on current research and applies to mothers who:
- have healthy, full-term babies;
- are storing their milk for home use (as opposed to hospital use);
- wash their hands before expressing;
- use containers that have been washed in hot, soapy water and rinsed.
All milk should be dated before storing. Storing milk in 2-4 ounce (60 to 120 ml) amounts may reduce waste. Refrigerated milk has more anti-infective properties than frozen milk. Cool fresh milk in the refrigerator before adding it to previously frozen milk.
Preferably, human milk should be refrigerated or chilled right after it is expressed. Acceptable guidelines for storing human milk are as follows.
What Type of Container to Use
The best options for storing human milk:
- glass or hard-sided plastic containers with well-fitting tops
- containers not made with the controversial chemical bisphenol A (BPA), identified with a number 3 or 7 in the recycling symbol. A safe alternative is polypropylene, which is soft, semi-cloudy, and has the number 5 recycling symbol and/or the letters PP. You can avoid the dangers completely by using glass bottle.
- containers which have been washed in hot, soapy, water, rinsed well, and allowed to air-dry before use
- containers may also be washed and dried in a dishwasher
- containers should not be filled to the top – leave an inch of space to allow the milk to expand as it freezes
Important: Plastic bottles and component parts become brittle when frozen and may break when dropped. Also, bottles and component parts may become damaged if mishandled, e.g. dropped, over-tightened, or knocked over. Take appropriate care in handling bottles and components. Do not use the breastmilk if bottles or components become damaged.
- freezer milk bags that are designed for storing human milk
- put only 60 to 120 ml (two to four ounces) of milk in the container (the amount your baby is likely to eat in a single feeding) to avoid waste
- Squeeze out the air at the top before sealing, and allow about an inch for the milk to expand when frozen.
- Stand the bags in another container at the back of the refrigerator shelf or in the back of freezer where the temperature will remain the most consistently cold.
Disposable bottle liners or plastic bags are not recommended. With these, the risk of contamination is greater. Bags are less durable and tend to leak, and some types of plastic may destroy nutrients in milk. Mark the date on the storage container. Include your baby’s name on the label if your baby is in a day care setting.
How to Warm the Milk
Frozen milk: thaw in the refrigerator overnight or under cool running water. Gradually increase the temperature of the water to heat the milk to feeding temperature.
Refrigerated milk: Warm the milk under warm running water for several minutes. Or immerse the container in a pan of water that has been heated on the stove. Do not heat the milk directly on the stove. Some babies accept milk right from the refrigerator.
Do not bring temperature of milk to boiling point.
Human milk may separate into a milk layer and a cream layer when it is stored. This is normal. Swirl it gently to redistribute the cream before giving it to baby.
Do not use a microwave oven to heat human milk. It may cause the loss of some of the beneficial properties of the milk. Microwaves do not heat liquids evenly and may leave hot spots in the container of milk. This could be dangerous for infants.
Sometimes thawed milk may smell or taste soapy. This is due to the breakdown of milk fats. The milk is safe and most babies will still drink it. If there is a rancid smell from high lipase (enzyme that breaks down milk fats) activity when the milk has been chilled or frozen, the milk can be heated to scalding (bubbles around the edges, not boiling) after expression, then quickly cooled and frozen. This deactivates the lipase enzyme. Scalded milk is still a healthier choice than commercial infant formula.
If you or your baby has a thrush or yeast/fungus infection, continue to breastfeed during the outbreak and treatment. While being treated, you can continue to express your milk and give it to your baby. Be aware that refrigerating or freezing milk does not kill yeast. After treatment is finished, any leftover milk that was expressed during the infection should be discarded.
Previously frozen milk that has been thawed can be kept in the refrigerator for up to 24 hours. While there is limited evidence to date that milk thawed for a few hours may be refrozen, this results in further breakdown of milk components and loss of antimicrobial activity. At this time, the accepted practice is not to refreeze thawed milk. While some mothers and caregivers reheat expressed milk that was leftover and refrigerated after a previous feeding, there is no research on the safety of this practice. There is also no research about whether freshly expressed milk left unfinished at room temperature should be discarded, or can be saved for a short time (perhaps up to one hour as reported by some mothers and caregivers) to finish the feeding if the baby wakens from having fallen asleep or still appears hungry.
Expressed milk can be kept in a common refrigerator at the workplace or in a day care center. The US Centers for Disease Control and the US Occupational Safety and Health Administration agree that human milk is not among the body fluids that require special handling or storage in a separate container.