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What is Your Breastmilk’s Shelf Life?

If you Google the refrigerator shelf life of breastmilk, you will find answers ranging from “three days” to “a week.” That is a big gap!

The question Google can’t answer is this: how long does your breastmilk last in the refrigerator?

This is good information to know for a few reasons:

  • If you have a short shelf life, you could be unknowingly be putting spoiled milk in the freezer.
  • If you have a long shelf life, you might be able to leave your milk in the refrigerator longer and avoid the extra step of freezing. This is particularly helpful when you are a working, pumping mom. Rolling the milk you pumped on Friday over to Monday without needing to freeze it is much more convenient than freezing and defrosting.
  • If you are traveling for more than a few days, you will need to know if you can get by with transporting your milk without needing to freeze it.

Here’s the experiment:

You will need about an ounce of milk for each “test day.” If you are a low supply mom, you could probably do this with half an ounce per day.  Hopefully, you will only be wasting one test day worth of milk. You will, however, be wasting one test day worth of milk. Brace yourself. I know it hurts.

Get yourself some milk to use as your test sample. You can do this by:

  • Pumping after a feeding. You will probably get the most milk if you pump after a morning feeding since the volume of your milk is highest in the morning. You want to pump no longer than 15 minutes after completing breastfeeding so you don’t cut into baby’s next feeding.
  • Pumping in place of a feeding. You could offer baby a bottle of milk you have in the fridge or freezer so that you can collect your fresh milk for the experiment.

Note: This is a good time to practice the bottle skill if you haven’t already. You should ideally introduce the bottle in the four- to six-week window and consistently offer it a few times a week, more often if you have a resistant bottle feeder.

Divide your milk into individual bottles. Put about one ounce in each. Label and date each bottle with the date you pumped it.

Okay. Now. You need a baseline of smell and taste. Yes, you need to smell and taste the milk. So, some people think tasting your own milk is disgusting. I don’t get that at all. I mean, your baby is eating it, so why wouldn’t you even taste it? If you have ever tasted your own sweat or licked the blood off your own cut, you have tasted bodily fluids that aren’t meant to be eaten. Just taste your damn milk.

Bonus: recruit a lab partner. If you want to have two opinions on when your milk spoils, recruit your partner to also smell and taste your milk each day. Here I would like to remind the two of you of how many “non-food” bodily fluids you have shared. This is your baby’s food, folks.

Okay, so now that you know how fresh milk tastes and smells, label the one-ounce bottles with numbers one through seven (these are the days you will be testing them). Put the corresponding date for the day you marked on the bottle.

So, if I pumped milk today, I would do this:

Each day, around the same time as when you pumped it if possible, check your milk. Smell it and taste it to determine if it is spoiled. If it is not spoiled, use it or freeze it.

Whatever day it spoils, your shelf life is the day before that. This means that if your milk is spoiled on day five, you need to use or freeze your milk no later than day four. Dump your spoiled milk. Sorry, I warned you.

There you have it. Now, for bonus points, take oldest non-spoiled milk and freeze it. Let’s just make sure you don’t have over-active lipase (more on this here).

2 Comments

  • Lara Zeises Deloza says:

    Oh, good! I’m glad you’re going to address the lipase thing. Our fridge is weird in that you have to kick the door shut to make the seal activate. Sometimes regular dairy will still spoil earlier than expected. So about 5 weeks into my pumping journey, when I finally had enough to start freezing some, I smelled/tasted the milk I was getting ready to freeze. It smelled fine but had a faint aftertaste of vomit. Thinking it was spoiled, I dumped it down the drain. I did this for about 20-30 oz. of milk before learning about lipase and how that was more likely the culprit. I want to sob when I think of all of that milk I wasted.

  • […] that you have figured out what the refrigerator shelf life of your breastmilk is, another important test is freezing and defrosting your […]