"Oh no, my ice is melting fast!"

By Ceres Chill


As all Ceres Chill moms know, the Demigoddess Chiller gives you 16 hours of safe storage and the OG Chiller gives you 20 hours of safe storage with just a handful of ice cubes and a splash of water. Adding the cubes to the chamber before heading out is necessary to bring down the temperature of your milk, and you may be concerned if you notice them melting after a couple of hours. We’re here to let you know that your milk is likely to be the perfect temperature, even if your cubes have melted — it’s part of how the Ceres Chill chiller works!


There are a few reasons why your ice may be melting before you’re expecting it to: 

  • The most common explanation is that it transferred its cooling capacity of about 30 degrees to your 98 degree milk as you’ve added it into the chiller. It works to equalize them at about 40-50 degrees. This is completely normal, and the high quality copper and bismuth seal is still working to maintain your milk at safe temperatures for the rest of the 16-20 hours. 
  • It’s also possible that you are adding too much water — all you need is a tiny splash to help the ice settle in! Too much water will speed up the ice melting.
  • Keep in mind that ice melting doesn’t mean your milk is unsafe. According to the Academy of Breastfeeding Medicine, your milk can be safely stored at up to 59 degrees Fahrenheit for up 24 hours.
  • If you’re in doubt, you can always sneak a few more cubes in just for peace of mind.


To get the maximum chilling capacity out of your Chiller, you want to make sure the ice is touching the bottom of the inner chamber. The ice and water don’t have to surround the inner chamber for your chiller to work beautifully.


If you’re using the 27-ounce method and are facing super-long travel or work shifts, you could consider freezing the inner chamber overnight for even longer cooling capacity. 


  • While it’s not necessary to use this method to safely store your breastmilk for long stretches of time, it can be useful for moms with extremely long days and demanding schedules. If you’re storing more than 20 ounces of breastmilk for over 16 hours, it might be a great hack for you. 
  • Be aware that the inner chamber was designed to be ultra-light for pumping and transporting purposes, so its stainless steel is thinner. Freezing it can cause the bottom of the chamber to bow out. Although 95% of moms who choose to freeze their inner chamber have no issues, our engineers have found that some freezers drastically drop in temperature and create a frozen "cap" on the top layer of water which forces the bottom out. This occasional issue is why we have to note this risk. If you think that this method would work for you,  be sure to fill it no more than 8 ounces and leave the cap off while freezing to help prevent distortion. Unfortunately though, damage is still a risk. If you don't want to take the risk in freezing it, you can stick with ice and a splash of water and refresh the ice if you feel that it's needed.



Lastly — and this is important — if you often notice your ice melting very quickly, make sure that your chiller's vacuum insulation seal is intact.


  • To test the chiller seal, add ice to the outer chamber and leave it sitting at room temperature for at least 20 minutes.
  • If the outside is very cold to the touch and developing condensation, the seal is likely broken. This can happen if the Chiller is badly dropped or otherwise abused. To ensure the highest quality and safety for infant use, instead of a lead seal we use a bismuth seal that can be broken under certain conditions. Reach out to us immediately if you suspect that your seal has been damaged!



Check out our Science page to learn more about the chilling capacity of our breast milk chiller — even when the ice is fully melted!

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