The short answer
University extension charts give about 1 to 4 months in a 0 F freezer. That range is for quality, not safety. These are the figures we found:
| Source | Freezer time at 0 F | Notes |
|---|---|---|
| Ohio State University Extension (Fayette County) | 1 to 2 months | Ice creams and sorbets. Overwrap to prevent ice crystals and freezer burn. |
| University of Illinois Extension | 2 months | For top quality. No split between opened and unopened. |
| University of Nebraska-Lincoln Extension | 2 to 4 months | Storage times are for quality only. |
None of these charts gives a separate figure for an opened tub and a sealed one. The sources we use do not cover that difference, so treat the range above as the guide for both.
Safe versus good: what “last” means
When people ask how long ice cream lasts, they usually mean two things at once: whether it is safe, and whether it is still good to eat.
FoodSafety.gov says freezer time limits are about quality only. Food kept frozen the whole time at 0 F (-18 C) or below can be kept indefinitely and stays safe. The Cuisinart instruction booklets also say your freezer should be at 0 F.
So does ice cream go bad in the freezer? Not in the safety sense, as long as the freezer holds 0 F. It does go downhill in quality. The University of Guelph’s Ice Cream Technology e-Book makes the point that there is no single shelf life for ice cream. Depending on storage it could be a year, or two weeks or less. Iciness, not spoilage, is the main limit.
Why ice cream gets icy in the freezer
The Guelph e-Book calls the process heat shock. When ice cream warms a little, its smallest ice crystals melt. When it freezes again, that water adds onto the larger crystals. You end up with fewer, bigger crystals, and the texture gets icier each time.
Two everyday things cause it:
- Freezer defrost cycles, which warm the inside of the freezer for short stretches.
- Handling, such as a tub left sitting on the counter while you scoop.
Temperature matters too. The e-Book says crystal growth stops below about -25 C. Above that point, crystals keep growing at a rate set by the temperature. A home freezer at 0 F (-18 C) is warmer than -25 C, so our reading is that ice cream keeps slowly getting icier even in a freezer that is working well.
Stabilizers slow this down. The Guelph e-Book notes that homemade ice cream usually has none, which is one reason a homemade batch can turn icy sooner.
How to store an open tub or homemade batch
These steps come from the extension charts and the machine makers:
- Keep the freezer at 0 F. That is the temperature every chart above assumes.
- Overwrap the container. The Ohio State chart says this helps prevent ice crystals and freezer burn.
- Move homemade ice cream out of the machine bowl. The Cuisinart booklet says to store it in an airtight, freezer-safe container, not in the freezer bowl.
- For a Ninja CREAMi, store leftovers in the pint. Ninja’s guide says to flatten the top before you refreeze it.
- Put the tub back quickly. This is our suggestion. Less time on the counter means less heat shock.
Shrinkage is a separate problem. The Guelph e-Book describes ice cream that pulls away from the sides and top of the container. It links this to very low or high storage temperatures, high overrun (a lot of air whipped in) and pressure changes.
Signs it has lost quality
The Guelph e-Book describes these quality defects:
- Coarse or icy: large ice crystals you can feel.
- Sandy: lactose crystals that do not melt in your mouth.
- Shrunken: the ice cream has pulled away from the container.
- Stale: what the e-Book calls a storage defect, where the ice cream lacks freshness.
- Off flavors picked up from the freezer: ice cream can absorb smells from around it, such as paint, ammonia or other foods.
- Oxidized: a cardboard-like, metallic, painty or fishy flavor.
- Rancid: a flavor caused by free butyric acid.
These are quality signs. The sources we use do not give a checklist for spotting unsafe ice cream by smell or look. FoodSafety.gov says you should never taste food to decide whether it is safe.
Can you refreeze melted ice cream
No. Once ice cream has truly melted, the guidance is to throw it out, not refreeze it.
After a party
The FDA says perishable food should not sit out for more than 2 hours, or more than 1 hour when it is above 90 F outside. If it sat out longer, discard it.
Our reading of the guidance draws a line here. Ice cream that went soft all the way through, or sat out past those limits, goes in the trash. A tub that softened only at the edges during a short serve and went straight back into the freezer is a different case. That is heat shock. It loses quality and gets icier, but the guidance does not treat it as a safety problem. You do not need to throw it out.
If you are serving outside, the Plan a cooler button under the intro opens our cooler calculator. You can use it to work out how much dry ice or regular ice to pack.
After a power outage
FoodSafety.gov’s power-outage table is strict about ice cream and frozen yogurt. It says to discard them in both cases it lists:
- The ice cream still contains ice crystals and feels as cold as if it were refrigerated.
- The ice cream was above 40 F (4 C) for more than 2 hours.
That is stricter than for some other dairy foods. In the same table, milk and soft cheese can be refrozen if they still contain ice crystals. A UConn Extension article from 2025 repeats the same table and credits it to USDA’s Food Safety and Inspection Service.
Our reading is that ice cream which thawed in a power outage goes in the trash, even if parts of it still feel frozen.
When a refrozen pint is hard
This is about texture, not safety. Ninja’s guide says that if a refrozen CREAMi pint is hard, you can process it again on the same program.
FAQ
How long does ice cream last in the freezer once opened?
The extension charts we found give 1 to 4 months at 0 F and do not separate opened from unopened. That range is for quality. At 0 F the ice cream stays safe as long as it stays frozen.
Does homemade ice cream last as long as store-bought?
The sources we use do not give a separate time for homemade ice cream. The Guelph e-Book notes that homemade ice cream usually has no stabilizers, and stabilizers slow the growth of ice crystals.
Is icy ice cream safe to eat?
Iciness is a quality problem, not a sign of spoilage. If the ice cream stayed frozen at 0 F the whole time, it is safe, just less smooth.
Can you refreeze melted ice cream after a power outage?
No. FoodSafety.gov’s outage table says to discard ice cream that thawed, even if it still has ice crystals.
What causes the gap between the lid and the ice cream?
The Guelph e-Book calls this shrinkage. It links it to very low or high storage temperatures, a lot of air in the ice cream and pressure changes.