Human breast milk

Storage Time

Freshly expressed human breast milk can be safely stored at room temperature (up to 25°C/77°F) for up to 4 hours, in the refrigerator (0-4°C/32-39°F) for up to 4 days, and in a standard freezer (-18°C/0°F) for 3-6 months. For optimal quality and nutrient retention, it can be stored in a deep freezer (-20°C/-4°F or colder) for up to 12 months. Thawed breast milk should be used within 24 hours and never refrozen.

Temperature

Optimal refrigeration at 0–4°C (32–39°F) and freezing at -18°C (0°F) or colder is essential for preserving the integrity and safety of breast milk.

Freezing

To freeze human breast milk effectively, use sterile breast milk storage bags or BPA-free, airtight containers, filling them to no more than three-quarters full to allow for expansion. Label each container clearly with the date of expression to ensure proper rotation. For thawing, transfer frozen milk to the refrigerator overnight, or hold the container under cool, then gradually warmer, running water. Avoid using a microwave to thaw or heat breast milk, as it can destroy valuable nutrients and create dangerous hot spots. Once thawed, breast milk should be used within 24 hours and must not be refrozen to prevent bacterial growth and nutrient degradation.

Signs of Spoilage

• A distinctly sour, rancid, or 'off' smell, which is different from its usual mild, slightly sweet, or sometimes soapy aroma.
• A chunky, curdled, or stringy texture that does not mix smoothly after gentle swirling, indicating protein breakdown.
• Any unusual discoloration, such as a greenish or dark yellow tint, or the presence of visible mold, which signifies bacterial contamination.