What do I need to know about storing my milk?

In addition to the milk storage times (see chart below), it also helps to know these points:

• Glass or plastic containers can be used.
• Milk freezer bags are also an option.
• Avoid thin bottle liners. These are meant to be used as feeding bags, but not for freezing milk. They can split when frozen.
• Store your milk in the smallest amount your baby might take. When your baby takes a bottle, her saliva mixes with the milk. You can always add to it, but don’t save your milk after part of it’s been given to your baby.
• Write the date and time on your milk container with a sticky label or non-toxic marker. Add your baby’s name if she is in daycare or in the hospital.
• You can combine milk pumped at different times. When combining milk from different days, write the date of the oldest milk on the container.
• If you plan to use your milk within 8 days, you can keep it in the fridge. Otherwise, plan to freeze it in the coldest part of the freezer. Avoid the door.
• If you follow the times on the chart below, you can keep your milk at room temperature, then refrigerate it, and then freeze it.
• You can add fresh milk to cooled milk. And you can add fresh milk to frozen milk if it’s cooled first and there is less of it than the amount frozen.
• Before freezing large amounts of milk, freeze a batch or two, then thaw and smell it. Some mothers make milk high in lipase, an enzyme that digests fat. When thawed, the frozen milk of these moms has a strong, spoiled smell. If this happens, scald the milk to deactivate the lipase before freezing. (To scald your milk, heat it in a pot on the range until bubbles form at the edges, then cool and freeze.)

Storage Time	Deep Freeze	Refrigerator Freezer	Refrigerator	Room Temperature
for Human Milk*	(0°F) (-18°C)	(variable 0°F) (variable =18°C)	(39°F) (4°C)	(66°F-72°F) (19°C-22°C)	(72°F-79°F) (22°C-26°C)
Fresh	Up to 12 Months	3-4 Months	8 Days	6-10 Hours	4 Hours
Thawed	Do Not Freeze	Do Not Freeze	24 Hours	1 Hour	1 Hour
*Storage times may vary for premature or sick babies. Sources: Jones, F. and M.R. Tully, Best Practices for Expressing, Storing and Handling Human Milk in Hospitals and Child Care Settings. Raleigh, NC: Human Milk Banking Association of North America, 2006; Mohrbacher, N. and J. Stock, The Breastfeeding Answer Book. Schaumburg, IL: La Leche League International, 2003

Why do I read different milk storage guidelines in different places?

Why can’t experts agree? First, research confirms that your milk will not spoil before the times listed on in the chart above. But the longer your milk is stored, the more vitamins are lost. That’s why some breastfeeding books list shorter storage times. Those experts prefer you use your milk sooner rather than later. But this doesn’t mean that your milk will be spoiled if you wait longer.

It’s never a bad idea to give your milk as soon as you can after pumping. But what should you do if you find some stored milk in the back of the fridge that has been there for up to eight days? When in doubt about the freshness of your milk, smell or taste it. Spoiled milk will usually smell spoiled.

Why do I need to warm my milk before feeding it to my baby?

An older, larger baby can handle drinking chilled milk. But milk needs to be warm for a tiny baby. If a newborn is fed cold milk, it can bring down your baby’s body temperature. Try to warm your milk to between room and body temperature.

Is there anything I should know about warming and thawing my milk?

HEAR ARE SOME POINTERS:

• Whether warming chilled milk or thawing frozen milk, keep the heat low. High heat destroys the antibodies in your milk that help keep your baby healthy.
• To warm your milk to between room and body temperature, put it under cool then warm running water. Keep water away from the bottle lid so that it doesn’t mix with the milk.
• One way to do this is to put a bottle in a bowl with the sides lower than the bottle’s lid. Run warm water in the bowl. The warm water against the sides of the bottle warms the milk.
• You can thaw frozen milk in the refrigerator.
• Your milk is not “homogenized” like the milk in the store. So it may separate into layers. If this happens, just gently swirl it to mix.

HERE ARE SOME “DON’TS” TO KEEP IN MIND:

• Don’t warm milk in the microwave. It changes the milk and causes hot spots that can burn your baby’s throat.
• Don’t heat the milk in a pot on the stove. High heat can make the milk too hot for your baby, and it destroys the antibodies your baby needs.