The expansion can cause the stainless steel walls of the Hydro Flask to deform and sometimes break the vacuum seal. In this case, your Hydro Flask no longer isolates properly. Thanks to the double-walled vacuum insulation, the water in the Hydro Flask does not freeze and you can put it in the freezer. If you want ice cold water, you should add ice cubes to your bottle to see how long it takes for it to melt.
While nothing bad will happen if you put your Hydro Flask in your freezer, it’s pointless. It won’t bring your water to freezing temperatures. With their advanced vacuum insulation and TempShield technology, Hydro Flask water bottles are great for keeping your ice cold drink for 24 hours a whole day, whether you’re staying at home or having a hot beach party in the summer season, you can rest assured that Hydro Flask will Bring your favorite cold drink anywhere, anytime. Yes, you can put wine in a Hydro Flask — a Hydro Flask can hold an entire bottle of wine and keep it at the same temperature for at least four hours.
Since Hydro Flask doesn’t offer much information on how to freeze their bottles, I wanted to do some more research to see if anyone else had frozen their Hydro Flask and what the results were.