How do you store baby bottles after sterilizing?

Quick Answers

There are a few key things to keep in mind when storing baby bottles after sterilizing:

  • Let bottles air dry completely before storing
  • Store sterilized bottles in a clean, covered container
  • Use bottles within 24 hours for optimal safety
  • Refrigerate leftover breastmilk immediately
  • Don’t reuse bottles more than a few times before sterilizing again

Let Bottles Air Dry

It’s important not to store bottles until they are completely dry after sterilizing. Any remaining moisture can allow bacteria to grow back quickly. After removing bottles from the sterilizer, stand them upright and allow them to air dry for at least 5 minutes before assembling nipples, caps, and collars and putting them into storage containers. Fanning bottles with a clean paper towel can help speed up the drying process if you are in a hurry.

Use a Clean, Covered Container for Storage

Once fully dry, sterilized bottles should be stored in a clean, covered container. This helps prevent contaminants in the air from getting into clean bottles. Some options for bottle storage include:

  • A clean cupboard or cabinet shelf dedicated to baby bottle storage. Be sure to regularly sanitize the shelf.
  • Clean zip top plastic bags or plastic containers with lids. Opt for bags/containers clearly marked for bottle use only.
  • Specialty bottle organizers and sterilizer bags designed for storing sterilized bottles.
  • Bottles with caps, nipples, and collars pre-attached can also be stored assembled in a clean container.

Use Bottles Within 24 Hours

For optimal safety and hygiene, sterilized baby bottles should be used within 24 hours. After this time period, bacteria levels can start to grow again and make the bottles unsafe for the next feeding. Any bottles not used within a day should be re-sterilized before their next use. When possible, only sterilize as many bottles as you expect to use during each 24 hour period.

Refrigerate Leftover Breastmilk

If a baby does not finish a full bottle of expressed breastmilk, the leftover milk should be immediately refrigerated. Seal the bottle and refrigerate for up to 24 hours. Discard any unfinished formula left in bottles – this cannot be reused due to bacterial contamination risk. Only reheat refrigerated breastmilk one time for the next feeding, and do not save any milk that baby does not finish the second time.

Don’t Reuse Bottles Too Many Times

Over time with repeated uses and washings, small scratches can develop in baby bottles and nipples. These microscopic scratches can harbor bacteria that is difficult to remove with sterilizing. It’s generally recommended to retire and replace bottles after the equivalent of roughly 250 washings. For most families, this equals about 2-3 months of use. Look for cracked, clouded, or worn bottle parts as signs it may be time to replace a bottle. Rotate bottles out to spread wear and tear.

Choosing the Best Sterilization Method

There are several effective options for sterilizing baby bottles, each with their own pros and cons. Here is an overview of common sterilization methods:

Method Pros Cons
  • Uses items already in your kitchen
  • Least expensive option
  • Time consuming
  • Bottles must be fully air dried after
  • Risk of burns from hot water
Steam Sterilizers
  • Fast and efficient
  • Automatic shut off when cycle complete
  • Models dry bottles after sterilizing
  • More expensive initial investment
  • Takes up counter space
Steam Bags
  • Inexpensive bags
  • Easy to use in microwave
  • Take up little storage space
  • Single use only
  • Bottles take longer to dry
  • Microwave safety concerns
  • Built into existing appliance
  • Cleans and sterilizes at once
  • Not as effective at killing all bacteria
  • Chemical residue can remain
  • Still requires drying

If you need a fast, effective method for sterilizing after each use, a steam sterilizer is likely the best investment. For occasional or travel use, microwave steam bags offer an inexpensive and easy option. And for emergency sterilizing with minimal supplies, boiling bottles is a reliable standby technique.

Step-by-Step Boiling Directions

If using the boiling method to sterilize baby bottles, follow these steps for proper technique:

  1. Wash bottles, nipples, caps, and collars thoroughly in hot soapy water first. Use a clean bottle brush to reach inside. Rinse all parts completely.
  2. Fill a large pot with water, leaving space for the bottles so it doesn’t boil over. Bring the water to a rolling boil.
  3. Use tongs to carefully place bottle parts into the boiling water, fully submerged. Leave for 5 minutes at a rapid boil.
  4. Turn off heat. Use tongs to transfer bottles to a clean drying rack or clean dish towel. Allow to air dry fully before assembly.
  5. After drying, store in a clean, covered container. Use within 24 hours.

Be cautious when sterilizing with boiling water due to risks of burns from the hot steam. Handle bottles carefully with tongs, and keep children away from the stove during the process.

Microwave Steam Bag Directions

Microwave steam sterilizer bags offer a quick, easy way to sterilize bottles with most types already having their own simple instructions to follow. However, keep these general guidelines in mind:

  1. Always start by washing all bottle parts thoroughly with soap and water before placing in the bag.
  2. Check that bottles and parts are completely clean of milk or formula residue so the microwave runs safely.
  3. Arrange bottles and parts so steam can fully circulate around each item.
  4. Add correct amount of water called for in the instructions.
  5. Heat the bag on full power based on time given on label, typically 5-8 minutes.
  6. Use potholders to remove bag carefully after microwaving.
  7. Allow bottles to dry fully before storing.
  8. Check your microwave wattage and do not exceed bag time limits.

Take extra care when using the microwave for sterilizing due to risks of burns and hot water splashes. Only use microwave-safe sterilizer bags and closely follow all instructions.

Electric Steam Sterilizer Directions

Electric steam sterilizers provide an efficient, easy way to sterilize multiple bottles at once. Models do vary, so always consult the user manual for your specific device. But general steps include:

  1. Take apart bottles and wash all parts in hot soapy water. Rinse thoroughly.
  2. Ensure water tank is filled to marked fill line with distilled water.
  3. Load bottles/parts into provided trays or baskets. Follow any layout guidelines.
  4. Turn on sterilizer and select desired cycle, often just 1-2 buttons.
  5. When finished, unload using provided tongs or potholders.
  6. Let cool and dry before assembling bottles for storage.
  7. Sterilized parts are safe for use for 24 hours.

Using an electric steam model properly minimizes any safety risks. Take care unloading sterilizer when freshly finished as items may still be hot.

Storing Breastmilk Safely

Properly storing expressed breastmilk helps preserve its nutrients and antibodies while keeping it safe for baby to drink. Follow these guidelines:

  • Store in Clean Bottles: Pump milk into sterilized bottles/bags designed for breastmilk storage. Avoid reuse of regular bottle sets.
  • Seal Bottles: Use tight fitting lids, caps, or zip-top freezer bag seals to prevent spills or contamination.
  • Label Bottles: Include date expressed and amount for tracking time limits.
  • Refrigerate Promptly: Get breastmilk into fridge within 4 hours; 1 hour optimal if hot/humid out.
  • Use Oldest First: When feeding baby, use oldest refrigerated milk before fresher bottles.
  • Coordinate Freezing: For longest storage, freeze milk within 24 hours of expressing. Move to fridge day before use.

Following safe refrigeration and freezing guidelines optimizes preserving your breastmilk supply for baby’s needs.

Troubleshooting Sterilizer Issues

If your bottle sterilizer is not performing properly, try these troubleshooting suggestions:

Issue Troubleshooting Tips
Cycle not starting
  • Ensure power plugged in, outlet working
  • Check water tank filled to indicator line
  • Confirm door fully latched/closed
  • Press start button firmly
Not heating up
  • Give unit 10-15 minutes to warm up from cold
  • Descale if mineral deposits in tank/chamber
  • Contact manufacturer if issue persists
Burning plastic smell
  • Avoid overloading chamber
  • Keep bottles from direct contact with hot plates
  • Stop use if odor persists, may indicate electrical issue
Not drying effectively
  • Select drying cycle option if available
  • Leave door ajar after cycle to air dry
  • Use dish drying rack to assist drying process

Be sure to review your instruction manual for troubleshooting tips specific to your sterilizer model and features. Contact the manufacturer if you continue to experience technical problems.

Best Practices for Bottle Maintenance

Following these best practices will help keep baby’s bottles clean and safe:

  • Clean bottles thoroughly after each use – don’t let milk/formula residue sit
  • Take apart all bottle pieces for cleaning
  • Alternate between bottle brush and sponge for scrubbing
  • Inspect for cracks/cloudiness/worn parts
  • Replace nipples every 2-3 months at minimum
  • Use dishwasher or sterilizer for deeper cleaning
  • Have enough bottles for 24-48 hour rotation
  • Store nipples/parts separately from bottles
  • Wash hands before handling cleaned bottles

Making bottle maintenance a regular habit will minimize risks of bacteria growth and contamination over their lifespan of uses.


How long can you store sterilized bottles?

Bottles are only considered sterile for about 24 hours after sterilizing. After this timeframe, bacteria levels can regenerate so bottles should be re-sterilized before the next use. Only prepare the number of bottles you expect to use during each 24-hour period.

Can you store assembled sterilized bottles?

It is possible but not ideal. Assembled bottles take longer to fully air dry, increasing bacterial growth risk. And wearing bottle nipples and collar parts repeatedly facilitates small cracks that breed bacteria over time. Storing bottles disassembled is best practice.

What temperature should sterilized bottles be stored at?

Sterilized bottles should be stored at normal room temperature after they are completely dry. Refrigerating sterilized bottles is not necessary and may actually cause unwanted condensation.

Do bottles need to be sterilized before first use out of the package?

Yes, it is recommended to sterilize bottles before their very first use. Manufacturing processes do not guarantee bottles to be fully sterile straight from the package. Sterilizing first helps remove any residual bacteria.

Can you reuse microwave steam sterilizer bags?

No, microwave steam bags are designed for single use only. The bags will weaken and become less effective with repeated microwaving. Follow instructions for correct water amounts and never reuse bags.

How do you sterilize pump parts?

Breast pump parts that contact milk should be sterilized just like bottles and nipples. Take apart flanges, valves, tubes, etc and sterilize fully assembled pump per manufacturer instructions. Air dry all parts completely before next use.

Is the dishwasher effective for bottle sterilizing?

Using the dishwasher is not considered a reliable method of fully sterilizing baby bottles. The hot water may sanitize bottles to an extent, but dishwasher temperatures are typically not high enough to kill all potentially harmful bacteria.


Following the proper preparation and storage steps after bottle sterilizing is key to keeping baby’s bottles safe and hygienic. Letting bottles air dry before storage, using clean containers, sticking to 24 hour usage limits, coordinating breastmilk storage, and frequently replacing worn parts will all optimize bottle cleanliness. Consistent bottle maintenance routines provide peace of mind at feeding time.

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