Keep out anything that expands inside a rigid container, anything held together by an emulsion, and anything crisp you intend to eat raw. What should you not put in the freezer comes down to two questions: will the container survive, and will the food still be worth eating afterward.
Almost none of these are safety problems. Our fridge and freezer storage chart covers where the real safety lines sit.
Food Safety Note
This article is general information about freezer storage in a home kitchen. It is not a substitute for the storage guidance on a product’s own label or for advice from a food safety authority. When any food has been handled or stored in a way you are unsure about, discard it rather than relying on a general rule.
Quick Answer
Eggs in the shell, unopened cans, carbonated drinks and full rigid containers all risk bursting. Mayonnaise, cream sauces, custards, sour cream and soft fresh cheeses separate. Lettuce, cucumber, celery and whole tomatoes turn limp. Fried food goes soggy. Already thawed food is the one genuine safety concern.
Key Takeaways
- Water expands as it freezes, which is why containers burst.
- Emulsions break when the water in them crystallizes.
- Crisp produce loses its structure permanently, not temporarily.
- Most of these foods are still safe, just unpleasant.
- Refreezing food that has thawed is the actual safety issue.
- Many rejects freeze fine if you plan to cook them rather than serve them raw.
- Leaving room at the top of a container solves a whole category of problems.
| Keep out | What goes wrong | Better route |
|---|---|---|
| Eggs in the shell | Contents expand and crack the shell | Crack and freeze beaten, in a container |
| Unopened cans | Seams can fail as contents expand | Open, decant, leave room at the top |
| Carbonated drinks | Pressure plus expansion bursts the container | Chill rather than freeze |
| Mayonnaise and cream sauces | The emulsion separates and goes grainy | Freeze the base, add dairy on reheating |
| Soft fresh cheeses | Watery and crumbly on thawing | Freeze hard cheese for cooking instead |
| Lettuce, cucumber, celery | Cell walls rupture, texture collapses | Buy smaller amounts more often |
| Whole tomatoes for salad | Skin splits, flesh turns mushy | Freeze for sauce, where mush is fine |
| Fried food | Coating goes soft and never crisps the same | Refrigerate briefly and reheat dry |
| Food that already thawed | Safety concern, not a texture one | Cook it first, then freeze |
Two Different Reasons to Keep Something Out
Almost every item on that list fails for one of two reasons, and separating them makes the whole subject easier to reason about.
The first reason is physical. Water expands when it freezes, so anything mostly water will grow, and anything rigid around it has to give.
The second reason is structural. Freezing forms ice crystals that pierce cell walls and break emulsions apart, and neither of those reassembles on thawing.
Neither reason makes the food dangerous. The Food and Drug Administration describes freezing at a proper storage temperature as keeping food safe indefinitely, with quality rather than safety being what declines over time.
So most of this article is about disappointment rather than risk. The exception gets its own section below.
Things That Expand and Break Their Container
Eggs in the shell
The contents expand, the shell cracks, and a cracked shell is an open route for contamination. Beaten eggs in a sealed container freeze without any of that, and yolks alone benefit from a pinch of salt or sugar to stay smooth.
Unopened cans and jars
A can is built for pressure from heat, not for contents pushing outward from within. Seams can fail, and a bulging can is one you discard rather than inspect.
Anything carbonated
Dissolved gas plus expanding liquid is the worst combination for a sealed container, whether glass, aluminum or plastic.
Containers filled to the brim
This is the version that catches people out with soups and stocks. Leave a gap at the top of the container, because the contents will occupy more space frozen than they do liquid. Our roundup of food storage containers covers shapes that make that gap easy to judge.
Emulsions and Dairy That Separate
An emulsion is fat and water held in suspension, and ice crystals are very good at undoing that arrangement.
Mayonnaise is the clearest example. It comes out of the freezer as oil sitting beside a watery curd, and no amount of whisking brings it back.
Cream sauces, custards, sour cream and plain yogurt all behave the same way to varying degrees. A sauce that will be blitzed or reheated hard sometimes recovers enough to pass, and one served as it is will not.
Soft fresh cheeses belong in the same group. Ricotta, cottage cheese and cream cheese all come back watery and grainy, while hard aged cheeses freeze acceptably if they are headed for a cooked dish. Our guide to storing cheese covers the better options for each type.
Butter is the useful exception, because its water content is low and it freezes well. Our note on whether butter needs refrigerating covers where it is best kept day to day.
The workaround for most of this category is to freeze the dish without its dairy and add that at the reheating stage.
Produce That Turns Limp
High-water vegetables are mostly crisp because their cells are full and intact. Freezing ruptures those cells, so the crispness is gone permanently.
Lettuce, cucumber, celery, radishes and raw whole tomatoes all come out soft and weeping. Nothing is wrong with them, and none of them will work in a salad again.
Whole citrus and melon split and collapse for the same reason, though the juice and the zest both freeze well on their own.
Raw potatoes deserve a particular mention, because they turn grainy and can develop an odd sweetness. Blanching first solves it, which is why commercially frozen potato products work and home-frozen raw ones often do not.
The practical answer for this category is buying less at a time rather than freezing the surplus. Our roundup of produce savers covers stretching the fridge window instead, and our guide to storing fresh herbs covers the one produce group where freezing genuinely is a good answer.
The One Genuine Safety Line
Everything above is a quality judgment. This part is not.
Food that has thawed and then sat warm should not go back into the freezer as it is. Freezing halts bacterial growth rather than reversing it, so whatever multiplied while the food was warm is still there.
The United States Department of Agriculture Food Safety and Inspection Service describes food thawed in the refrigerator as safe to refreeze without cooking, while food thawed by other methods should be cooked before it goes back in.
FoodSafety.gov applies the same principle to perishable food left at room temperature, which should be discarded rather than refrozen after the safe window has passed.
Our guide to defrosting food safely covers which thawing method leaves that option open and which ones close it.
What to Freeze Instead
- Leave a gap in every container. This alone prevents the whole bursting category.
- Freeze sauce bases without the dairy. Stir cream or yogurt in when you reheat.
- Blanch vegetables you intend to freeze. It stops the enzymes that ruin texture and color.
- Freeze tomatoes for cooking, not for salad. Mush is acceptable in a sauce.
- Crack eggs before freezing them. Beaten, sealed, and labeled with the count.
- Cook before refreezing anything that thawed warm. Then freeze the cooked dish.
- Freeze bread properly rather than avoiding it. It is one of the best candidates there is.
Our guide to storing bread covers that last point, and our roundup of mason jars covers a container type that works well for freezing provided you respect the gap at the top.
Related Reading
Frequently Asked Questions
What should you not put in the freezer?
Eggs in the shell, unopened cans, carbonated drinks and containers filled to the brim all risk bursting. Mayonnaise, cream sauces, custards, sour cream and soft fresh cheeses separate. Lettuce, cucumber, celery and salad tomatoes turn limp. Fried food goes soggy.
Are these foods unsafe after freezing?
Mostly no. The Food and Drug Administration describes freezing at a proper storage temperature as keeping food safe indefinitely, with quality declining rather than safety. Almost everything on the list is a texture or flavor disappointment. Refreezing food that thawed warm is the real exception.
Why do containers burst in the freezer?
Because water expands as it turns to ice. A container filled to the top has nowhere to put that extra volume, so something gives. Leaving a gap at the top of every container prevents it, whatever the container is made of.
Can I freeze milk and cream?
Milk freezes acceptably and often separates slightly, so shake it well after thawing and expect it to suit cooking better than a glass. Heavy cream freezes better than milk does. Whipped cream and sour cream both come back poorly.
Why did my frozen tomatoes turn to mush?
Their cells were full of water, and freezing ruptured the cell walls. That change is permanent. Frozen tomatoes work well in sauces and soups where softness does not matter, and they will not work in anything served raw.
Can I freeze raw potatoes?
Not well. Raw potatoes turn grainy and can develop an odd sweetness. Blanching them first stops the enzyme activity responsible, which is why commercial frozen potato products hold up and home-frozen raw ones usually disappoint.
Is it ever safe to refreeze thawed food?
Yes, in one case. The USDA Food Safety and Inspection Service describes food thawed in the refrigerator as safe to refreeze without cooking. Food thawed in cold water or a microwave should be cooked before it goes back, and perishable food left out warm gets discarded.
What freezes better than people expect?
Bread, butter, hard cheese for cooking, cooked grains, stock, beaten eggs, herbs in oil, and most cooked dishes without a cream base. Bananas and berries freeze well for anything blended, even though their texture changes completely.
Sources
- United States Department of Agriculture, Food Safety and Inspection Service. Freezing and food safety.
- FoodSafety.gov. Cold food storage and safe handling.
- Food and Drug Administration. Refrigerator and freezer storage guidance.
