Dry ice is a great way to keep food frozen or cold longer when camping, fishing or hunting. It's colder than regular ice, doesn't make everything wet and it helps to keep all your food safe in your cooler.
But can you use a combination of regular ice and dry ice? Can you put regular ice on top of dry ice?
Yes, you can put regular ice on top of dry ice. It might make the dry ice disappear a little bit faster but the dry ice will make the regular ice much colder. Once the dry ice is gone your regular ice will continue to keep things cold in your cooler.
This is a popular method for keeping your cooler cold for longer and extending the life of your regular ice.
What Happens When You Put Regular Ice On Top of Dry Ice?
Dry ice is made from frozen carbon dioxide. This is the same stuff they put in sodas to make them fizzy.
Dry ice does not react with water/regular ice so you don't have to worry about any explosions or harmful chemical reactions.
Dry ice is SUPER COLD at -109ºF (0ºC). In comparison, regular ice at 32ºF (0ºC) is hot compared to dry ice.
Because water is denser than air it also transfers more heat.
If you put regular ice on top of dry ice the regular ice will heat up the dry ice causing it to sublimate (turn to gas). At the same time the dry ice will cool down the regular ice making it colder.
Over time the dry ice will disappear first, turning from a solid into a gas. Depending on the quality of your cooler and how much dry ice you use this could happen in as little as a few hours or your dry ice might last 3+ days. More on how long dry ice lasts in a cooler.
Once the dry ice is completely gone you'll be left with regular ice that is much colder than it usually would be in a normal freezer or cooler.
But now there is no dry ice to keep it cold your regular ice will start to warm up and eventually start to melt.
Will Dry Ice Keep Ice Cubes From Melting?
Yes dry ice will keep ice cubes from melting.
At -109ºF (-78ºC) dry ice is much much colder than regular ice and so when regular ice is on top or near dry ice the dry ice will keep the regular ice from melting.
It'll even cause the regular ice to become much colder than it usually would be in a regular freezer.
Once all the dry ice runs out it is no longer there to keep the regular ice cubes cold. So once the dry ice is gone your ice cubes will begin to warm up and will eventually start melting.
How to Load Dry Ice and Regular Ice In a Cooler
If you want to combine dry ice and regular ice in a cooler you want to do it properly to maximize the life of your dry ice so it keeps everything frozen longer.
You can begin by placing the blocks of dry ice on the bottom of your cooler. Place them side by side and pack them together if you have enough.
The less air space between each dry ice block the longer they will last.
Then you can dump the regular ice on top of it. You can put in a layer of this ice on top of the dry ice and shake the cooler to make sure that the ice cubes get into all of the dead space.
Dead spaces allow the cooler to warm faster, so it is important to make sure that you fill them with ice as much as you can.
Once you have the regular ice in, you can load your cooler with your food and drinks.
If you want to keep things frozen put them closer to the dry ice. If you want to keep things cold but not frozen then put them as far away from the dry ice as possible.
Add Dry Ice to the Top If You Need to Keep Everything Frozen
If you want to keep everything frozen inside of the cooler, you can place another layer of dry ice on top.
Be sure to wrap it in newspaper so that it doesn’t touch your food directly as this cause freezer burn and ruin the taste and texture of your food.
The dry ice on top will disappear faster than the dry ice on the bottom, so anything that MUST stay completely frozen place near the bottom layer of dry ice.
Also, don't open your cooler unless you absolutely have to! Every time you open it you introduce warm air melting all your ice faster.
Also cheap coolers have empty lids with no insulation so the dry ice on top will disappear faster. However, more expensive coolers like Yeti have lids that are full of insulation. So if you're trying to keep everything frozen then I suggest a roto-molded cooler. Click here to see my recommendations for the best coolers for dry ice.
This is a great idea if you have food that is perishable because it will maintain a safe temperature until you return home. This way, your game from hunting or other perishable foods will not spoil.
It is important to slow down the sublimation of the dry ice by filling air pockets in dead spaces with ice cubes or balled up newspapers. This will ensure that your dry ice lasts as long as you need it to.
People often want to know if they can put regular ice on top of dry ice, and the answer is that you can.
You should always start with the dry ice on the bottom and make sure that your cooler has ventilation so that the carbon dioxide has room to expand as it sublimates.
The dry ice will keep your ice cubes frozen longer, and the ice cubes can help to fill the dead space in the cooler.
This will ensure that you keep food and drinks colder for a longer period of time.
If you have perishables in the cooler, you might consider putting another layer of dry ice on top.
Separate it from your food and drinks with newspaper, cardboard, or cloth. You will have your own dry ice refrigerator ready for any situation.