Hydro Flasks are made to keep water and other drinks cold for hours or even longer than an entire day. They are also built from stainless steel and designed to be tough and handle the extreme outdoors.
But what about the fridge? Can you put a Hydro Flask in the refrigerator? Or is it possible that the refrigerator will actually somehow damage your Hydro Flask and cause it to stop working? After all a Hydro Flask can't go in a dishwasher.
I often like to prepare my water bottle at night and put it in the refrigerator overnight to keep it cold. Then in the morning I can just grab it and go. But I wanted to make sure doing this is not going to break my Hydro Flask.
I couldn't find an obvious warning from Hydro Flask about it so I did some research to see if there are any risks or if you can safely put your Hydro Flask in the fridge. Here's what I found:
You can safely put Hydro Flasks in the refrigerator. They are designed to handle cold and hot temperatures and the fridge poses no risk to it. The vacuum insulation of the Hydro Flask will mean your fridge won't cool your drinks well, but it'll keep them cold longer.
However, you cannot put your Hydro Flask in the freezer. The way liquids expand as they freeze can bend the metal of your Hydro Flask and potentially break the vacuum seal, which will ruin it's insulation.
But the fridge should be completely fine.
The reason people think you can't put it in the fridge is because Hydro Flask (and other brands) warn against putting your bottle in the freezer, but they don't really explain why so people just naturally think you can't put it in the fridge either.
But the fridge and freezer are very different. Putting your Hydro Flask in the fridge is fine.
What Does Hydro Flask Say About Putting Their Bottles In The Fridge?
I couldn't find a great deal from Hydro Flask about whether or not you can't put them in the fridge.
On their Bottle Care Instructions page they do state you shouldn't put your Hydro Flask in the freezer but they don't explain why and they don't say anything about the fridge.
Because they don't say not to put it in the fridge I'd assume it's ok.
There is this question on Amazon where someone asks if they can put it in the fridge. The response from Tall Ridge (Hydro Flask's only authorized Amazon seller) and they say:
“The entire Hydro Flask line is vacuum insulated, which means there is an absence of matter between the two stainless steel walls. Since there is no matter, the temperature outside of the flask has a difficult time affecting the temperature of the contents inside the flask. So no, you do not need to put your Hydro Flask in the fridge.”
Truthfully they don't really answer the question which is a little frustrating. But other people on the same page say it's fine and that they do it.
Given than Hydro Flasks are designed to be used in the great outdoors and sometimes in sub freezing temperatures then yes, it should be fine to keep your Hydro Flask in the fridge and you shouldn't have any issues.
It won't cool your drink down very quickly which we'll talk about next, but it shouldn't damage your bottle.
Will a Drink In Your Hydro Flask Get Cold in The Fridge?
When you ask the internet whether or not you can put a Hydro Flask in the fridge the resounding response is “why bother?” which isn't exactly helpful.
Given that Hydro Flasks are marketed as keeping drinks cold wouldn't it make sense to keep them in the fridge?
However, Hydro Flask keep drinks cold because they are double walled with a layer of vacuum insulation in between the walls. The vacuum insulation stops most heat transfer.
This means it stops heat getting into your Hydro Flask on a hot sunny day, but it also stop the cold getting it when you put your bottle in the fridge (I mean technically the fridge is drawing heat out but you know what I mean.)
So if you put a bottle of room temperature water in a Hydro Flask and put it in the fridge it will eventually cool down to the temperature of the fridge, but it'll take a long time.
The insulation stops fridge from cooling down your drink. But it's not perfect so eventually your drink will cool down to the temperature of your fridge.
To speed up the process it's a good idea to leave the lid of your Hydro Flask off when putting it in the fridge. That way it can cool down faster.
Why Can't You Put Hydro Flasks In The Freezer?
Hydro Flask clearly state in their care instructions:
Put your Hydro Flask in the freezer: Due to the double wall vacuum insulation, the water inside will be protected from the temperature inside the freezer and won’t freeze. If you want ice cold water, put some ice cubes inside your flask and notice how long it takes them to melt!
But they don't really explain what might happen if you do put your Hydro Flask in the freezer. Why is the fridge fine but not the freezer?
While Hydro Flask don't state why you shouldn't put it in the freezer but after doing my research I discovered this article by Contigo (a competing brand who make similar products) that explained it simply.
When liquids freeze, they expand and take up more space. As the liquid freezes and expands, it can cause your water bottle or travel mug to become deformed and misshapen.
Even worse, the expanding liquid might break the welds and seals holding your water bottle together. If you place a stainless steel water bottle in a freezer, you might unintentionally and up damaging the vacuum seal, causing it to lose its insulating properties and not keep your water cold for as long. Ironic, right?
When you place your Hydro Flask in the freezer eventually your drink inside will begin to freeze.
As it starts to freeze the liquid will expand in all directions and put pressure on the inner walls of your Hydro Flask bottle. It won't only expand up but can also expand outwards bending the metal in the process.
It's possible for the liquid to deform your bottle enough to actually break the vacuum seal.
The inner compartment will then fill up with air and the cup will no longer insulate as well. Learn why Hydro Flasks can stop working.
Now instead of having a bottle that will keep ice for more than a day you've just got an expensive metal bottle that might keep ice a couple of hours at best.
Why Is It Safe To Put a Hydro Flask In The Fridge?
The reason we don't have the same issues with the fridge that we do with the freezer is that the fridge isn't going to cause your drink to freeze. This means your drink won't expand and it won't deform the bottle or break the vacuum seal.
Hydro Flasks are made from stainless steel and are designed to handle cold temperatures really well. People take them in sub zero temperatures and have no problems
The fridge isn't special. It's just a cold environment that your Hydro Flask bottle can easily handle.
The vacuum will insulate your drink and this means it'll take the fridge a long time to cool down your drink. It won't cool down nearly as quickly as a drink in a plastic or glass water bottle, but it will cool down eventually.
The fridge will also help to keep ice water or an iced drink cold for a longer period of time in your Hydro Flask because it's being exposed to less outside heat.
For a lot of people Hydro Flasks keep drinks cold for long enough that they don't need to worry about refrigerating them. But if you want to put your Hydro Flask in the fridge then by all means go for it. It shouldn't cause any damage and it'll keep your drinks colder for longer.
Just don't expect your fridge to rapidly cool down your room temperature water.