Freezing and Thawing of Milk

Some general guidelines to remember:

• Fresh milk may be placed in a separate deep freeze (chest-type freezer) for 6-12 months. Milk can sometimes be stored even longer if it is immediately frozen and is frozen at the lowest possible temperature (-20 degrees). If previously kept at room temperature, or stored in a cooler or refrigerator before freezing, storage time may vary. Deep freezing is best for recipients with donors that live farther than driving distance.
• Previously frozen milk may be kept in the refrigerator for up to 24 hours after it has completely thawed.
• Avoid wasting milk by using only small amounts at a time, keeping the primary bag/bottle in the fridge and feeding an ounce or two at a time from a separate feeding device until you know your baby's eating patterns well.
• For local donation, fresh milk may be placed in a freezer compartment inside a refrigerator for up to 2 weeks. If it has previously been kept at room temperature, in a cooler, or in the refrigerator, storage time may vary. If milk must be shipped after freezing in a traditional freezer, it is best to ship milk as soon as possible.
• Freshly expressed breastmilk may be kept in a self-contained freezer unit of a refrigerator for up to 3-6 months, depending upon how often the door is opened. Store milk in the back of the freezer. If the milk has been stored at room temperature, in a cooler with icepacks, or in the refrigerator prior to being placed in the freezer, safe freezing time may be decreased.
• Milk that is truly bad has a very distinct sour taste and odor. Even if expressed milk is "out of date" it should still be considered safe to give a baby as long as it still has a fresh odor and/or taste.
• Milk recipients should own a deep freezer for storing milk until it is used.

HANDLING AND THAWING

Fresh human milk separates into milk and cream, so it is important to gently swirl the container to mix the milk before offering it to your baby.

For Donors: While it was originally thought that a mother had to cool her fresh breastmilk before combining it with previously expressed cooled milk, the latest research now shows that you may pump directly into already refrigerated or cooled milk as long as the milk is added within 24 hours of the first milk expressed. You should then follow the storage recommendations based upon the time and date of the first milk expressed. The milk should then be immediately placed in a deep freeze. You may add your fresh milk to what you have already frozen as long as you chill the fresh milk first for about half an hour and it is a smaller amount than the amount that you are adding it to. With milk that you will use, it is generally best to store in portions of 2-4 ounces to avoid less waste. Milk recipients will often pool and pastuerize milk, though, therefore making it unecessary to worry about the quantity of milk that you store in each container. Discuss this with your recipient.

For Recipients: When thawing milk it is best to thaw it in the refrigerator. This takes about 12 hours. If you need a quicker method you may hold the container under water that is gradually warmed or you may place it in a bowl of water that again is gradually warmed. Another, newer method that affords a faster warm is the Avent bottle warmer. This warmer allows for a gradual warm and has been tested on breastmilk and not shown to affect any of the milk's properties. Regardless of the method of warming you choose, shake the container before testing the temperature. Human milk should NEVER be microwaved or heated directly on the stove! These heating methods alter the composition of the milk and may result in hot spots in the milk that could perhaps burn your baby! Once thawed, breastmilk should not be refrozen. It also should not be reheated once heated.

Extensive research has not yet been done to determine if it is safe to give a baby milk that was left over from a previous feeding or milk that was previously warmed, but not used. However, most lactation experts agree that milk that is not finished at one feeding may be offered at one more feeding before needing to be discarded. Human milk has antibacterial and antimicrobial properties that result in slower spoilage as compared to other foods.

APPEARANCE OF STORED MILK

The appearance of stored milk can take on many forms. Most moms notice that after a while the fats in the milk begin to separate from the body of it. They may rise to the top or settle on the sides of the storage container. Before emptying the milk into your baby's bottle, cup, or supplemental feeder and right before serving it to baby, be sure to gently swirl the milk so that the fats can be redeposited back into the rest of the milk.

Milk that has been expressed can look thin and some moms may think this appearance means that their milk is low in fat. Human milk does not look like cow's milk in its container. Cow's milk has been homogenized giving it a more white appearance than cow's milk that has not been homogenized or expressed human milk. At other times, the milk may take on different tints of color. This can be in relation to something mom has eaten or a medication she is taking. The color of the milk is not harmful to the baby. And keep in mind that if the milk was not expressed, noone would be any wiser as to its appearance as it left the breast straight into baby's mouth.