An opened can of Kendamil powder formula stays good for 4 weeks. Ready-to-feed bottles last up to 24 hours in the fridge once opened. These timelines vary depending on which type of Kendamil you’re using and how you store it, so here’s a full breakdown.
Powder Formula: 4 Weeks After Opening
Once you pop the lid on a can of Kendamil powder, you have 4 weeks to use it up. After that point, the fats in the powder can start going rancid and key nutrients like vitamins A and C begin to break down. The formula may still look fine, but its nutritional quality drops. A simple trick: write the date you opened the can directly on the lid so you’re never guessing.
During those 4 weeks, store the open can in a cool, dry place like a pantry or cabinet. Kendamil recommends keeping it between 13 and 24°C (roughly 55 to 75°F). Don’t put the powder in the fridge. The humidity inside a refrigerator causes clumping, which makes it harder to measure accurately and can introduce moisture that speeds up spoilage. Keep it away from direct sunlight and never let it sit anywhere above 35°C (95°F).
Ready-to-Feed: 24 Hours Once Opened
If you’re using Kendamil’s ready-to-feed liquid bottles, any unused portion that hasn’t touched a nipple can go in the fridge for up to 24 hours. After that, toss it. Once you’ve attached a teat and the baby has fed from the bottle, do not save and reuse it. Bacteria from your baby’s saliva begin multiplying in the formula almost immediately, so any leftover liquid from a feeding should be discarded.
Prepared Bottles: A 2-Hour Window
When you mix Kendamil powder with water, the clock starts ticking faster. A prepared bottle that’s sitting out at room temperature is safe for up to 2 hours. If you know you won’t use it right away, put it in the fridge immediately, where it will keep for up to 24 hours.
Once your baby starts drinking from the bottle, the window shrinks further. The CDC recommends using a bottle within one hour of the start of a feeding. After that, bacteria from saliva can multiply to levels that cause digestive problems. This applies to all infant formula, not just Kendamil. If your baby falls asleep mid-feed and doesn’t finish, it’s safer to pour out what’s left and make a fresh bottle when they wake up.
Quick Reference by Format
- Unopened powder or liquid: Good until the expiration date on the package, stored in a cool, dry place.
- Opened powder can: Use within 4 weeks. Store at room temperature, not in the fridge.
- Opened ready-to-feed bottle (unused): Refrigerate and use within 24 hours.
- Prepared bottle (powder mixed with water): 2 hours at room temperature or 24 hours in the fridge.
- Bottle baby has started drinking from: Use within 1 hour, then discard.
How to Tell if Formula Has Gone Bad
Even within the recommended timeframes, formula can spoil if it’s been stored poorly. With powder, watch for clumping, a change in color (darker or off-colored), or an unusual sour smell. These are signs that moisture or heat has gotten to it. With liquid formula, look for separation, curdling, a foul odor, or any change in consistency. If the packaging is bloated or damaged, don’t use it regardless of the date.
If something seems off but you’re not sure, err on the side of making a fresh batch. Formula is one area where “when in doubt, throw it out” genuinely applies.
Why Kendamil’s Guidelines Are Stricter
You might notice that Kendamil’s storage recommendations are slightly more conservative than what you’d see from some American formula brands. Kendamil is manufactured in Europe and follows NHS guidelines, which tend to be stricter than those from the American Academy of Pediatrics. The core difference is mostly about prepared bottles: the NHS is more cautious about how long mixed formula should sit. This doesn’t mean other brands are unsafe, just that Kendamil defaults to tighter windows. When the instructions on your specific can differ from general advice you’ve read online, follow the can.