Soapy, sour or metallic tasting breast milk? Lipase may be the cause.
Lipase is a naturally occurring component in breast milk and in our digestive systems. It helps our body break down the fat we eat and use it inside our bodies. Lipase helps keep your baby healthy by allowing your body to absorb the nutrients from your breast milk.
Our bodies need some lipase but if your breast milk has too much, it digests the fat in your milk and leaves behind a soapy, metallic or sour taste. Sadly, many mothers discover their milk has excess lipase after pumping and storing several ounces. Once lipase has changed the taste of the milk, it cannot be returned to the original state. The stored breastmilk is safe for your baby to drink, but many babies will refuse the bottle because of the change in flavor and odor.
To test for excess lipase:
Place 2-3 ounces of breastmilk in the refrigerator. Every hour, smell and taste a small amount of the milk. Write down the time you notice a change in the smell and taste. Do this until you find a consistent time. Some moms find their milk changes within 1-2 hours, others find the milk takes 18-20 hours to change.
If your milk has excessive lipase, you will need to take some additional steps before freezing your milk:
• To neutralize the lipase, you will need to heat your milk to 180 degrees.
• Most moms pour their milk into a metal bottle, then use a bottle warmer without an automatic safety shut off (otherwise the bottle warmer will not allow your milk to get to the high temperature required).
• A bottle warmer that submerges the entire bottle, rather than just part of the bottle will raise the temperature of your milk faster.
• Stir your milk gently with the thermometer.
• Using a metal bottle will allow you to place the bottle into an ice bath immediately after reaching 180 degrees. Use caution when quickly cooling a glass bottle, it may shatter.
• Many moms heat their pumped milk upon returning home at the end of the workday. You might ask your partner to heat and cool your milk while you breastfeed.
If you need to heat your milk at work but can't use the bottle warmer, consider the microwave. Typically, microwaving breastmilk is not recommended. The high, uneven heat of the microwave can inactivate some components in your breastmilk. However, if your baby is doing some drinking from the breast and the microwave is the only option for preserving your milk, it may be a good choice.