Should you use the “Fridge Hack?”

If you’re pumping regularly, you’ve probably heard of the “fridge hack” — storing used pump parts in the fridge between sessions instead of washing them every time. It’s a huge time-saver, and many parents find it makes pumping more sustainable.

Here’s how to do it thoughtfully — and what to keep in mind.

What is it?

The fridge hack means placing your used pump parts in a clean container in the fridge between pumping sessions. Cold temperatures slow bacterial growth, so your parts can safely wait for the next pump without an immediate wash.

1.The CDC discourages it — but safety issues haven’t been documented.

The CDC recommends washing after every use (and sanitizing for babies under 2 months). But there’s no real-world evidence linking the fridge hack to illness in healthy, full-term babies.

The CDC’s concern is theoretical — that bacteria on refrigerated parts could grow and contaminate milk. However, both fresh and refrigerated breastmilk contain immune and antibacterial factors that help inhibit bacterial growth.

And it’s interesting that, despite known high-risk concerns for powdered infant formula contaminated with pathogenic bacteria cronobacter and salmonella, the CDC does not devote this same level of universal precaution to formula prep. Whereas the WHO recommends preparing all powdered formula with water heated to 158°F ( in order to kill pathogenic bacteria in both water and the powdered formula), then cooling to body temp before feeding, the CDC only recommends preparing powdered formula with boiling water for some babies “under 2 months, born prematurely, or with weakened immune systems.”

Bottom line: more research is needed to support pumping and storage recommendations that make it practical for families to meet their feeding goals, while also keeping their baby safe. And until then, using the fridge hack does technically go against CDC guidance. But we’re always here to help you make informed and practical choices for your family.

2. Weighing risk vs. benefit

For many parents, the fridge hack makes the difference between fitting in a pumping session — or skipping it. The small theoretical risk of bacteria has to be balanced with the real risks of stress, skipped sessions, and early weaning—something that has well-documented implications for the long-term physical and mental health of both parent and baby. Supporting parents to meet their feeding goals is also a key part of infant health.

3. Best for older, healthy babies

If your baby is healthy, full-term, and over 8 weeks old, their immune system has matured significantly, and any amount of breastmilk you’ve already provided has helped them to build it. For them, the fridge hack is going to be lower risk. If your baby is younger, premature, or has health concerns, providing breastmilk through consistent pumping can still be an especially critical way to help build and train their immune system, shape their microbiota, and establish a protective gastrointestinal barrier. If this is your baby, the fridge hack might still make sense for you–just talk to your IBCLC, or pediatrician about it first, to weigh your individual circumstances.

4. Store parts properly

Use a clean, lidded container (like Tupperware) — not a plastic bag. Place a paper towel in the bottom to absorb condensation. Wash your container, and change the paper towel daily.

5. DON’T rinse your parts before refrigerating

It might feel counterintuitive, but rinsing can actually increase bacterial risk. Residual water creates a moist environment where bacteria can grow. Breastmilk, on the other hand, contains natural antimicrobial properties that help inhibit bacterial growth.

6. Only skip 1-2 washes

Use the fridge hack sparingly:
🕐 Pump → 🥶 Fridge Hack → 🕐 Pump →🧼 Wash → Repeat
And if you only pump a few times a day, don’t go more than 8-12 hours on the fridge. Label your tupperware with the time you put them in the fridge.

This keeps things both efficient and safe.

7. Extra sets of pump parts can make life easier

If you pump multiple times a day, you may find it easier to have an extra set (or two) of pump parts on hand to reduce the stress of constant washing. You can still use the fridge hack 1-2x with each set.

8. Sanitize every few days

If you’re regularly using the fridge hack, consider sanitizing your parts every few days to ensure you’re starting with parts that are as clean as possible. This might be as easy as just be popping them into your dishwasher on the sanitize cycle.

8. Practice good “pumping hygiene” overall

If you’re using the fridge hack, give a good look to the CDC guidelines for cleaning and storing your parts and try to really maximize your pumping hygiene at the other points along your routine. These hygiene recs all have important evidence behind them:

  • Don’t let parts touch the sink or shared sponges.

  • Always let parts fully air-dry — moisture = bacteria.

  • Store clean parts in something washable (like Tupperware or a zippered, machine-washable bag), not reused plastic bags.

  • 🚗 Mind your pumping space:
    If you pump in your car or a shared room, wipe surfaces or use a clean mat. And never let anyone make you pump in a bathroom.

  • 🙌 Hands matter:
    Wash or sanitize before handling your parts — especially if you’ve been using your phone or other high-touch surfaces.

  • 🥶 If washing has to wait:
    When the CDC’s “wash as soon as possible” isn’t possible (because, baby), the fridge can be the best place to keep your used parts until you’re ready to wash.

  • 👃 Coming soon:
    Next week — how your pumping routines and storage habits can affect the smell and taste of your milk, and how to prevent problems months from now!

Bottom Line

The fridge hack can be a total game-changer for simplifying your pumping routine — especially when used thoughtfully and in combination with good pumping hygiene. While it’s technically not CDC-recommended, there’s no evidence that it poses a risk to healthy, older infants, and many parents find it invaluable for making pumping sustainable.

As always, trust your instincts and talk with your lactation consultant or pediatrician if you have concerns about your specific situation.

Katie Shamp