Yeti tumbler cups are great at keeping water ice cold for 24+ hours and they can keep your tea or coffee hot for up to 12 hours. But can you put milk in a Yeti tumbler cup?
Is it safe to store milk in a Yeti cup and if so how long can you store the milk before it starts going bad and you need to toss it away?
My kids love cold milk and love milkshakes so the idea of making them one for later when we are driving or out for the weekend seemed like a great idea.
But I also wanted to make sure it would be safe for them. So I did my research into whether or not you can keep milk in a Yeti tumbler cup and here's what I found.
You can keep milk in a Yeti tumbler cup for 2-6 hours depending on it's starting temperature and how hot it is outside. To make it last longer start the milk off as close to freezing temperature as possible and use reusable ice bricks like myColdCup in order to keep the milk cold.
The key to keeping milk safely in a Yeti tumbler cup is to keep it at or below 40ºF (4ºC) for as long as possible.
How To Keep Milk Safely In a Yeti Cup
Milk needs to be kept below 40ºF (4ºC) otherwise the bacteria lactobacilli can grow and multiply, which spoils your milk and if left too long can lead to food poisoning.
To keep cold milk safely in a Yeti cup you want to make sure that this milk is below that temperature.
From 40-140ºF (4-60ºC) is considered by the USDA to be the “danger zone” for bacteria growth in food. Milk is a type of food especially susceptible to this danger zone.
The general advice is that you should keep milk for no longer than 1-2 hours in the danger zone before discarding it.
So the idea is to keep the milk in your Yeti cup below this danger zone temperature for as long as possible and once it warms up into this range then you have 1-2 hours to drink your milk before you need to discard it.
Start Your Milk Out at a Colder Temperature
One way to keep milk longer in a Yeti tumbler is to start the milk out at a colder temperature.
A fridge usually keeps milk around that 40ºF (4ºC) mark, just outside of the danger zone.
You want to get your milk as close to freezing temperature as possible without actually freezing it.
Put it in the back of the fridge right in front of the cold air vent or place it in the freezer for a bit before putting it in your Yeti tumbler cup.
Starting out colder means it will last longer with less risk of growing bacteria.
Chill The Inside of Your Yeti Tumbler
This doesn't have a huge effect but it's still a good idea to pre-chill the inside of your Yeti tumbler before pouring milk in there.
The stainless steel at room temperature can add heat to your milk as you pour it in.
To pre-chill it fill your cup up with ice or iced water and leave for 10-30 minutes to cool down the metal.
Then discard the ice or iced water and pour your cold milk into your cup
The Best Way To Keep Cold Milk in a Yeti Cup: A Reusable Ice Brick
Milk by itself in a Yeti tumbler cup will allow you to keep it for 2-6 hours before you risk drinking off milk.
However, if you add a reusable ice brick then you can often keep milk for 12-24 hours without issue.
You don't want to put loose ice in your milk, because while it'll work to keep your milk cold as the ice melts it'll dilute your milk.
Reusable ice bricks won't dilute your milk as they melt, so they will keep it cold and fresh and out of the danger zone without ruining the milk.
An ice brick like the myColdCup drinks ice brick at Amazon are designed to fit into cups and bottles and will do the trick perfectly.
If you're in a pinch of don't want to spend the money then putting some ice cubes in a zip lock plastic bag and putting that in your Yeti cup could do the trick too.
But the ice bricks are so cheap and in my opinion are worth the small investment.
Can You Put Hot Milk in a Yeti Cup?
When it comes to putting hot milk in a Yeti tumbler cup again you need to be aware of the “danger zone” for milk and keep it out of this range.
You can put hot milk in a Yeti cup but you'll want to make sure it's OVER 140ºF (60ºC) the entire time, otherwise harmful bacteria can grow. Hot milk can last approximately 2-6 hours in a Yeti cup or even longer if it stays extremely hot. However, prolonged heat exposure leads to denaturing causing the milk to change flavor and consistency.
Ideally you want to preheat your Yeti cup by filling it with boiling water and leaving it to stand for 2-5 minutes.
Heat up your milk to near boiling temperature and then discard the boiling water and pour your hot milk into your Yeti cup and quickly put the lid on.
Yeti cups can keep drinks hot for 6-12+ hours however as I mentioned above you want to be aware of the danger zone temperatures.
Milk contains lactobacilli bacteria which can grow quickly between 40-140ºF. So keep “warm” milk is a really bad idea because within as little as 1 hour it can completely go off and eventually become extremely harmful to drink.
If you're super paranoid then getting a little pocket thermometer can help ease your mind as you can see whether or not the milk is hot enough that it's still safe to drink. This cheap little thermometer at Amazon should do the trick.
But for most people a sniff test will be enough to tell, or a little sip taste test.