Store breast milk

Nicole Wendler holds a PhD in biology in the field of oncology and immunology. As a medical editor, author and proofreader, she works for various publishers, for whom she presents complex and extensive medical issues in a simple, concise and logical manner.

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How you store breast milk depends on whether you want to feed your baby right away or later. It is important to maintain the quality as long as possible. In addition to hygiene, other factors also play a role in storing breast milk. Read here how long breast milk can be kept and what you should consider when freezing, transporting or thawing breast milk.

Store breast milk: storage

When it comes to storing breast milk, there are a few things to keep in mind. You can avoid contamination if the breast milk ends up directly in the container in which it is to be stored when expressing. It should be a clean, sterilized and well sealable container. Containers made of glass or hard plastic (polycarbonate) and special milk bags from various manufacturers are suitable. They are sterilized and of tested quality. Kitchen utensils such as ice cube trays, normal freezer bags, plastic bottles or baby bottles that were manufactured before 2011 should not be used to store breast milk. They can contain plasticizers (phthalates, di-ethylhexylphthal) and bisphenol A (in polycarbonate).

In order not to exceed the shelf life, the date and time must be written on the container. In the hospital, the baby's name should also be noted on it to avoid confusion. Special guidelines for storing breast milk apply to premature and sick children. They must be clarified with the respective hospital.

Breast milk: how long can I keep?

Various substances in breast milk inhibit the growth of bacteria. Therefore, breast milk has a longer shelf life than industrial baby food. The exact shelf life depends on how you store the breast milk, whether at room temperature, in the freezer or in the refrigerator.

Store breast milk at room temperature

If the room temperature is between 18 and 20 degrees Celsius, you can store the breast milk without refrigerating it - but only for a maximum of eight hours. If the baby does not drink the milk within this period, it must be put in the refrigerator immediately.

Store breast milk in the refrigerator

Breast milk can be stored for more than eight hours if it is stored in the refrigerator. It is best not to put the container in the door, but in a lower compartment further back. The temperature there is lower and remains constant at around four to six degrees. You can keep your breast milk there for three to five days.

Freeze breast milk

If breast milk is not fed in the refrigerator within five days, it should be frozen. It is best to do this immediately after pumping, not after five days. Portions with around 60 to 120 milliliters of breast milk are practical. Shelf life and quality are guaranteed for six months at minus 18 to 20 degrees Celsius. It is usually not that cold in an integrated freezer compartment in the refrigerator. You should therefore check the temperature of your refrigerator: lower freezing temperatures reduce the shelf life.

Because frozen milk will expand, do not fill the container completely. Leave about three inches to the edge.

Store breast milk: mixing allowed

You can collect several pumped servings a day in one container. However, the fresh, warm milk first has to cool for an hour before it can be mixed with a cold portion that has already been expressed. When storing frozen breast milk, you can pour chilled milk from the refrigerator onto frozen milk. The amount added should be less than the already frozen supply and also well chilled so that the frozen portion does not thaw.

Thaw breast milk

If you want to thaw frozen breast milk, you have to proceed slowly and gently so as not to destroy the ingredients. To do this, simply put the frozen milk in the refrigerator for 24 hours. The breast milk can then be warmed up or stored in the refrigerator for a further 24 hours. Once opened, it only lasts for a maximum of 12 hours in a cool place.

Warm up breast milk

If you want to warm breast milk, this must also be done carefully, for example under warm water, in a warm water bath or in a bottle warmer at a maximum of 37 degrees. Valuable ingredients such as vitamins and unsaturated fatty acids are lost through overheating. You should therefore never use the microwave to warm or thaw breast milk. It is enough if breast milk is at room temperature.

Once warmed up, milk should be drunk quickly. Check the temperature on the back of your hand beforehand. Storing breast milk if it was warmed up more than an hour ago is not an option. The same goes for rewarming. Keeping breast milk warm is also not a good idea, as microorganisms multiply in the process.

Store breast milk: transport

If mother and child are spatially separated, it may be necessary to transport expressed breast milk. With frozen milk, the cold chain must not be interrupted, i.e. the milk must not be thawed during transport. Cool bags with cooling elements are ideal for this.

Storing breast milk: good to know!

If the shelf life of breast milk is exceeded, these milk residues can still be used as a bath additive.

If breast milk stands for some time - in the refrigerator or at room temperature - a layer of fat forms on the surface, which is dissolved again by gently shaking it. The lower layer can appear yellowish or bluish in color. When storing breast milk, this is completely normal and not a sign that the milk is inedible.

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