How long does it keep?
Formula and breast milk storage limits, at a glance.
Storage limits
| Room temperature | In the fridge | |
|---|---|---|
| Formula made from powder, not yet fed | 2 hours | 24 hours |
| Any bottle the baby has drunk from | 1 hour, then bin it | Do not refrigerate it |
| Ready-to-feed poured into a bottle | 2 hours | 24 hours |
| Ready-to-feed, opened container | Refrigerate it | 48 hours |
| Liquid concentrate, opened | Refrigerate it | 48 hours |
| Freshly expressed breast milk | 4 hours | 4 days |
| Breast milk left after a feed | 2 hours | Keep for the next feed |
| Breast milk mixed with formula | 2 hours | 24 hours |
| Opened tin of powder | 4 weeks | Do not refrigerate powder |
The one people get wrong: a bottle the baby has drunk from does not go in the fridge. Saliva adds bacteria that cold slows but does not kill, and they restart from a higher count when it rewarms. One hour, finished or not.
Breast milk is more generous than formula everywhere except after a feed. Mix the two in one bottle and the formula limits apply, because you cannot give the longer limit to a liquid that contains the shorter one.