How Long Can Formula Sit Out?

Proper storage of baby formula is essential for your little one's health and safety. Using expired or improperly stored formula can pose risks, such as bacterial growth, leading to potential illness. In this article, we'll explore various aspects of formula storage and handling, focusing on the question: how long can formula sit out? You can also reference this helpful tool from the CDC.

Formula Preparation Guidelines

When preparing baby formula, it's important to follow the instructions on the packaging closely. This includes using the correct water temperature, as too hot or too cold water may impact the formula's effectiveness. Be sure to always measure the water first and formula powder accurately to provide your baby with the right balance of nutrients. It is never safe to dilute formula by adding extra water.

How Long Can Formula Sit Out At Room Temperature?

The CDC recommends prepared formula be used within an hour from the start of feeding and within 2 hours of preparation. If you aren't going to feed your baby within 2 hours, the bottle should be stored in the refrigerator and used within 24 hours. Any leftover formula should be thrown away - the combination of formula and baby saliva can cause bacteria to grow. 

How Long Is Formula Good In The Fridge?

If you need to store prepared baby formula for a longer duration, refrigeration is the best option. Prepared formula can be safely stored in the refrigerator for up to 24 hours. Opened containers of liquid concentrate or ready-to-feed formula can also be refrigerated but must be used within 48 hours. When using refrigerated formula, ensure it is mixed well before feeding.

How Long Is Unopened Formula Good For?

The shelf life of unopened baby formula depends on the type and brand. Generally, it can last a few months to over a year. To make sure you're using the freshest formula for your baby, always check the expiration date on the packaging. Store unopened formula in a cool, dry place, away from direct sunlight. That's because improper storage can affect the formula's quality and safety. If the expiration date has passed, toss the formula. Using expired formula might not be safe for your baby, as it could have decreased nutritional value or potential bacterial growth.

Should You Reheat Formula?

While it is not necessary to warm infant formula , you or your baby may prefer  to warm the formula before feeding. Use safe methods such as a bottle warmer or a bowl of warm water and avoid getting water into the bottle or nipple. Never use a microwave, as it can create hot spots that could burn your baby's mouth. Ensure the formula is at a comfortable temperature by testing it on your wrist before feeding – it should feel warm, not hot

When To Discard Formula

Knowing when to discard formula is essential for your baby's health. Prepared bottles of formula should be used or disgarded within 24 hours of preparation. Signs of spoiled formula include a sour smell, clumps, or discoloration. If you're unsure about the formula's freshness, it's always best to err on the side of caution and discard it.

Traveling With Baby Formula

Traveling with baby formula requires careful consideration. Bring along a cooler with ice packs to keep the formula at a safe temperature. Pre-measured powder can be stored in a separate container for easy mixing when needed. Remember to follow the same guidelines for storage and feeding when you're on the go.

Should Formula Be Frozen?

Freezing baby formula is not recommended, as it can cause the texture to change and separate, impacting its quality and nutritional value. Instead, prepare and store smaller batches of formula to minimize waste and ensure freshness.

Tips for Formula Storage and Handling

Proper storage and handling of baby formula can help keep your baby safe and healthy. Here are some tips to follow:

  1. Wash hands: It is important to always wash your hands well with soap and water before handling bottles containers, and formula
  2. Label containers and bottles: To avoid confusion, clearly label the containers and bottles with the date and time of preparation.
  3. Prepare formula in advance: If you need to prepare formula ahead of time, store it in the refrigerator immediately. Remember to use it within 24 hours.
  4. Clean bottles and equipment: Regularly clean and sterilize bottles, nipples, and other feeding equipment to prevent bacterial growth.
  5. Store formula containers properly: Keep unopened formula containers in a cool, dry place away from direct sunlight. Once opened, tightly seal and store powdered formula in a cool, dry area for up to one month.
  6. Avoid cross-contamination: Use a separate, clean scoop for each formula type, and do not touch the formula powder with your hands. Keep the formula container's lid and rim clean to prevent bacteria from entering.
  7. Be cautious with prepared formula: If you have doubts about the prepared formula's freshness or storage conditions, it is better to discard it and make a fresh batch to ensure your baby's safety.

Storage Times for Different Types of Formula

There are various types of baby formula, each with specific storage requirements and expiration dates. The most common types include powdered, concentrated liquid, and ready-to-feed. However, specialized formulas, such as hydrolyzed or lactose-free, also have unique storage guidelines. Always check the manufacturer's instructions for accurate information.

Tips for Safely Cleaning, Sanitizing, and Storing Formula Feeding Items

To ensure the health and safety of your baby, it's essential to properly clean, sanitize, and store all formula feeding items. Here are guidelines based on recommendations from the Centers for Disease Control and Prevention.

How Often Should I Clean My Baby’s Bottle?

It's recommended to clean baby bottles after each and every feeding. Unfinished formula left in a bottle for more than 2 hours should be discarded to prevent the growth of harmful germs.

How To Clean: Dishwasher Method

If your feeding items are dishwasher-safe, they can be run through the dishwasher. First, disassemble all parts of the bottle and rinse them under running water. Then, place them in the dishwasher, ideally using a hot water cycle and a heated drying cycle to eliminate more germs. Always wash your hands before removing and storing cleaned items.

How To Clean: Hand Wash Method

If you're cleaning feeding items by hand, start by washing your hands thoroughly. Disassemble all bottle parts and rinse them under running water. Then, place all items in a clean basin filled with hot soapy water and scrub them with a clean brush dedicated to this purpose. Rinse the items again under running water and let them air-dry on a clean, unused dish towel or paper towel.

Cleaning Brushes and Basins

Brushes and basins used for cleaning bottles should be rinsed well and allowed to air-dry after each use. Wash them every few days, either in a dishwasher or by hand with soap and warm water.

Cleaning Infant Formula Containers and Scoops

While there's no evidence to suggest that contamination on the outside of a formula container can make a baby sick, you can still choose to clean the container with a disinfectant wipe or paper towel sprayed with disinfectant. The scoop used for powdered formula generally doesn't need to be cleaned unless it gets dirty.

Remember, these guidelines are meant to ensure the safety and health of your baby. Proper cleaning, sanitizing, and storing of formula feeding items can help prevent the growth of harmful germs and keep your baby healthy.


Following baby formula storage and bottle cleaning guidelines are essential for your baby's health and safety. By adhering to these best practices, you can make sure your baby receives the nutrients they need while minimizing the risk of illness. Remember to consult your pediatrician with any concerns or questions related to your baby's nutrition and well-being.

Wondering which type of formula is best for your baby? Check out our baby formula quiz to make the most informed decision.