I discovered (by a bottle-refusing baby, vomit-smelling milk, and my breastfeeding support group) that I have an excess lipase issue. Due to this, my milk changes smell and taste much faster than normal. To stop this process, I have to scald my milk before it can be frozen. Freezing milk does not stop the process. I've found that my milk lasts a little less than 2 hours unrefrigerated, and about 24 hours refrigerated. I've only frozen scalded milk. 

The scalding process does slightly reduce the nutritional benefits of the milk, but as long as baby only gets scalded milk occasionally it is not a problem. This is why I did not have a big stash of milk and was not away from my baby very often or for long periods of time. 

To scald breastmilk, you must heat it to 163F and keep it at that temperature for 15 seconds. or you can just let it hit a temperature of 180F and immediately start cooling. I typically let mine go past 163F and then it would keep rising a few degrees during those 15 seconds before I dunked it into ice.
Source: Lawrence R, Lawrence R. Breastfeeding: A Guide for the Medical Profession, 6th ed. Philadelphia, Pennsylvania: Mosby, 2005: 156-158, 203-205, 771, 781.

Having the right tools makes this scalding process much easier. If you have high lipase levels in your Breastmilk, I highly recommend the supplies listed below to treat your milk before storing it. Most warmers will not get the temperature high enough due to having an automatic shut-off. 

The RIGHT Tools:

The process is SO MUCH EASIER with the bottle warmer and taller thermometer. The stainless steel bottle is KEY. Plastic bottles take much longer to warm the milk. Who has time to wait for that???

Before I purchased these items I was warming my milk on the stove. IN A POT. It was terrible. My hands were burning with steam, the top-heavy thermometer would threaten to tip over the bottle, and it took forever.
The Wrong Tools (don't do this):

The ExpectingHappiness Lipase Breastmilk Scalding Instructions:

1) Combine milk into one bottle, write measurement of volume on the storage bag you plan to use (bottle measurements are more accurate than the bags).

These would actually add up to 4.75oz

2) Place stainless steel bottle of milk in the bottle warmer- set the time to 2:00-3:00 minutes, fill with water according to directions. Watch the thermometer to see what time you get to the 163F mark. This is a bit of a learning curve, but you’ll start to know how long each amount takes to scald (my typical 4oz batches took around 2 minutes). Or heat milk to about 180 F (82 C) and immediately remove bottle from the warmer.
3) Remove bottle and put in a bath of cool water.

4) Once milk has reached room temperature (doesn’t feel warm to the touch), funnel milk into a breastmilk storage bag. I find breastshields to be the perfect size funnel!

5) Put freezer bags into larger gallon storage bag (just in case of leaks) to keep all the milk organized (Always store milk in the BACK of the freezer away from the varying temperatures of the door, lay flat on side so the milk freezes flat).

6) When it is time to use your frozen milk, I recommend defrosting overnight in the fridge, just put it in a large bowl in case your bag leaks (my bags NEVER leaked, but I am paranoid!). Pour into a bottle, and tell your baby to enjoy!

Here’s some more information on the Stainless Steel Bottle; and the Bottle Warmer.

Let me make this easy for you... just click the links below to order!

The following information on Lipase is from KellyMom:

Does your milk smell or taste soapy?
A few mothers find that their refrigerated or frozen milk begins to smell or taste soapy, even though all storage guidelines have been followed closely. Per Lawrence & Lawrence (p. 781), the speculation is that these mothers have an excess of the enzyme lipase in their milk, which begins to break down the milk fat soon after the milk is expressed. Most babies do not mind a mild change in taste, and the milk is not harmful, but the stronger the taste the more likely that baby will reject it.

Lipase is an enzyme that is normally present in human milk and has several known beneficial functions:
  • Lipases help keep milk fat well-mixed (emulsified) with the “whey” portion of the milk, and also keep the fat globules small so that they are easily digestible (Lawrence & Lawrence, p. 156).
  • Lipases also help to break down fats in the milk, so that fat soluble nutrients (vitamins A & D, for example) and free fatty acids (which help to protect baby from illness) are easily available to baby (Lawrence & Lawrence, p. 156).
  • The primary lipase in human milk, bile salt-stimulated lipase (BSSL), “has been found to be the major factor inactivating protozoans” (Lawrence & Lawrence, p. 203).
  • Per Lawrence & Lawrence (p. 158), the amount of BSSL in a particular mother’s milk does not vary during a feed, and is not different at different times of day or different stages of lactation.
  • There is evidence that there may be a decrease in lipase activity over time in mothers who are malnourished.
  • Many mothers who need to store their expressed milk but have problems with excess lipase sometimes wonder whether changing their diets may help.
KellyMom discusses other options for scaling here:

Once the milk becomes sour or rancid smelling/tasting, there is no known way to salvage it.
If you have frozen milk in your freezer that your child refuses, here are some options:
  • Try mixing the “rejected” frozen milk with fresh milk. Start with half frozen, half fresh and adjust the amount of frozen milk up or down depending on your child’s preferences.
  • Consider donating your frozen milk to a milk bank. Lipase and other taste issues are not typically an problem for milk banks. Visit HMBANA for more information and to find your closest milk bank.
If you have any questions about scalding your milk, feel free to email me:

Making the lives of busy moms easier!

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    1. Purchased these supplies and did my first bag tonight. Was really easy and thank you for simplifying the process. I was unsure where to begin with all of this.

  3. Can milk be scalded in storage bag rather than stainless steel bottle?

  4. Lovely post and the baby is so cute!

  5. Thank you for this post. It's nice knowing cool ways of storing breast milk and use them with baby bottles.



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