Yes—you can refrigerate prepared baby formula if your baby has not started drinking from the bottle. Put it in the refrigerator promptly and use it within 24 hours of preparation. If feeding has begun, discard any formula left in the bottle within 1 hour from the start of the feeding. Do not save it for later.
These time limits apply to prepared infant formula. Opened powdered formula should be kept tightly closed in a cool, dry place—not in the refrigerator. Always follow the storage directions on your formula label when they are more restrictive.
This guide is educational and is not a substitute for advice from your pediatrician. Babies younger than 2 months, babies born prematurely, and babies with weakened immune systems may need additional precautions.
Baby Formula Storage Times at a Glance
| Situation | Safe storage rule |
|---|---|
| Freshly prepared, feeding has not started | Use within 2 hours of preparation, or refrigerate promptly and use within 24 hours |
| Baby has started drinking | Use or discard within 1 hour from the start of feeding; do not refrigerate leftovers |
| Prepared formula in the refrigerator | Use within 24 hours of preparation |
| Opened powdered formula | Keep tightly closed in a cool, dry place; do not refrigerate |
| Prepared or powdered formula in the freezer | Do not freeze unless the product label explicitly directs otherwise |
Can You Refrigerate Prepared Formula?
Prepared formula can go in the refrigerator only when it has not touched your baby's mouth. The safest routine is to refrigerate it immediately if you are preparing it for later. The CDC says prepared formula should be used within 2 hours of preparation. If feeding will not begin within that period, refrigerate the bottle and use it within 24 hours.
Keep the refrigerator at 40°F (4°C) or below. Store bottles toward the back of the refrigerator, where the temperature is more stable, rather than in the door. Label bottles with the preparation time if you prepare more than one.
How Long Can Formula Stay in the Fridge?
Prepared formula that has not been offered to your baby can remain refrigerated for up to 24 hours from the time it was prepared. The clock does not restart when you remove or warm the bottle.
If you cannot remember when a bottle was prepared, discard it. Smell, taste, and appearance are not reliable ways to decide whether infant formula is safe.
Can You Put Leftover Formula Back in the Fridge?
No. Once your baby starts drinking, saliva enters the bottle and can allow bacteria to grow. Refrigeration does not make that leftover bottle safe for a later feeding. The CDC recommends using prepared formula within 1 hour from the start of feeding and throwing away what remains.
To reduce waste, prepare a smaller bottle and make more only if your baby is still hungry.
Can You Freeze Baby Formula?
Do not freeze prepared formula unless the manufacturer specifically says you can. Freezing can cause separation and changes in texture, and the FDA's storage guidance directs parents to refrigerate prepared formula for no more than 24 hours rather than freeze it.
Opened powdered formula also should not be refrigerated or frozen. Moisture can enter the container and affect the powder. Keep the lid tightly closed and follow the package instructions for how soon to use it after opening; the FDA notes that opened powder typically needs to be used within one month, but the product label controls.
Can You Refrigerate Ready-to-Feed or Liquid Concentrate Formula?
Storage depends on whether the container has been opened and whether your baby has fed directly from it. Follow the manufacturer's label for opened ready-to-feed formula or liquid concentrate. Any formula remaining in a bottle your baby drank from must still be discarded within 1 hour from the start of feeding.
How to Prepare Bottles Ahead of Time
- Wash your hands and use clean feeding equipment.
- Prepare the formula exactly as directed on the product label. Do not add extra powder or extra water.
- Cap the untouched bottle and refrigerate it promptly.
- Mark the preparation time.
- Use the refrigerated bottle within 24 hours.
- Warm only the bottle you are about to use, if warming is desired.
For the warming steps, see How to Warm Formula From the Fridge Safely. For brand-specific mixing ratios, use our Baby Formula Preparation Guides.
Frequently Asked Questions
Can I refrigerate formula immediately after making it?
Yes. If your baby has not drunk from the bottle, refrigerate it promptly and use it within 24 hours of preparation.
How long can formula sit out before refrigeration?
Use prepared formula within 2 hours of preparation. If you will not start feeding within that time, place it in the refrigerator promptly rather than waiting until the 2-hour limit.
Can I refrigerate formula after my baby drinks from it?
No. Discard leftovers within 1 hour from the start of feeding because saliva can allow bacteria to grow.
Can I put warmed formula back in the fridge?
Do not return a warmed feeding bottle to the refrigerator for another feeding. Warm only the amount you expect to use and follow the product label. Once feeding starts, discard leftovers within 1 hour.
Can formula be served cold?
Yes. Infant formula does not need to be warmed. If your baby accepts it cold, a properly refrigerated untouched bottle can be served without warming.
Should powdered formula be kept in the refrigerator?
No. Keep opened powder tightly closed in a cool, dry place and follow the use-by directions on the container.
Last reviewed: July 2026. Safety guidance checked against current CDC and FDA recommendations. Always follow the instructions on the formula container and seek medical advice for individual feeding needs.