A bottle doesn't need to be warm, it needs to be lukewarm: roughly as warm as your own skin. Milk that is too hot can burn your baby's mouth and throat, and with breast milk, valuable components are lost at high temperatures.
The short answer
- Breast milk: warm slowly to about 37 °C, your body temperature.
- Formula: body temperature is the norm. Kind en Gezin (the Flemish child and family agency) says room temperature is also fine, if your baby drinks it well.
- Always test: drip a drop onto the inside of your wrist. Lukewarm is right, warm is too warm.
Warming breast milk
Kind en Gezin advises warming breast milk slowly to 37 °C, in a bain-marie or a bottle warmer. That way the antibodies and nutrients are preserved as well as possible.
- No microwave, or at most 10 seconds on the lowest setting, then swirl and test again. A microwave heats unevenly.
- Thawed milk should be used within 24 hours and never refrozen.
- Leftover warmed breast milk can be used for up to 1 hour at room temperature.
Preparing and warming formula
The powder itself is not sterile. So always prepare a bottle just before use, with still, low-mineral water suitable for infant feeding. Don't store a prepared bottle, not even in the fridge, and pour away any leftovers.
Why not warmer?
A baby's mouth is more sensitive than the inside of your wrist. Milk that feels nicely warm to you is already too hot for your little one. Body temperature is what your baby is used to from the breast.
How long can a warmed bottle stand?
As briefly as possible. Bacteria grow fastest in lukewarm milk. That's why, with the Monkilou bottle warmer, we recommend keeping breast milk warm for 30 minutes max. For formula: don't let your baby drink for longer than half an hour, and throw away what's left.
In practice, on the go
A portable bottle warmer such as the Monkilou bottle warmer warms the milk through direct contact in a stainless steel chamber, without water or a plug socket. You choose the temperature: 37 or 40 °C for breast milk, 45 or 50 °C for formula. Even then, always test a drop on your wrist.
This article is general information and does not replace medical advice. If in doubt, ask your midwife, doctor or Kind en Gezin.