Is It Safe to Drink Soda After It’s Been Frozen?

Drinking soda that has been frozen and then thawed is not dangerous from a food-safety standpoint. The liquid itself does not become toxic or chemically harmful because it spent time in a freezer. The real concerns are more practical: cans and bottles can burst or crack, the carbonation largely disappears, and the flavor often changes in ways that make the drink less appealing. Whether it is “safe” depends on what you mean by the word, because the soda inside the container is fine, but the container itself may not be.

Why Soda Explodes in the Freezer

Water expands by roughly nine percent when it turns to ice. Soda is mostly water, so the same thing happens inside a sealed can or bottle. On top of that expansion, carbon dioxide that was dissolved under pressure starts coming out of solution as the liquid freezes. That released gas takes up additional space. A standard aluminum can or a sealed plastic bottle has very little room to absorb that extra volume, so pressure builds until the container gives way.

Aluminum cans tend to split along their side seams or blow out the top. Plastic bottles can bulge and sometimes crack at the cap seal. Glass bottles are the most hazardous because glass shatters rather than bending, leaving sharp fragments mixed in with frozen soda. If you find a can that has burst in the freezer, the mess is annoying but the soda clinging to your frozen vegetables is not hazardous in any unusual way. If a glass bottle has broken, however, treat it like any broken glass around food and discard everything it touched.

The freezing point of soda is slightly below the freezing point of plain water because of the dissolved sugars, acids, and carbon dioxide. Most regular sodas start to freeze around minus one to minus two degrees Celsius (roughly 28 to 30 degrees Fahrenheit). Diet sodas, which contain less dissolved sugar, freeze at temperatures closer to plain water’s zero degrees Celsius. That difference is small enough that both types will freeze solidly in a standard household freezer set to around minus eighteen Celsius.

What Happens to the Carbonation

The fizz in soda comes from CO2 dissolved in the liquid under pressure. As the soda freezes, the forming ice crystals push dissolved gas out of the liquid phase. The CO2 migrates toward whatever unfrozen pockets remain and eventually builds up as gas inside the container. Once you thaw the soda, that gas is no longer dissolved in the liquid the way it was before. Even if the can or bottle survived intact, the drink will be noticeably flat when you open it.

You can sometimes recover a small amount of carbonation by thawing the container slowly in the refrigerator, keeping it sealed the entire time. The cold liquid can reabsorb some of the free CO2 if there is still pressure inside. But the recovery is partial at best. If you are someone who drinks soda mainly for the fizz, a previously frozen can is going to disappoint you.

Flavor and Texture Changes After Thawing

Freezing does more to soda than just removing the bubbles. When a sugary liquid freezes, the water crystallizes first and the dissolved sugars, acids, and flavoring compounds get pushed into the remaining liquid pockets. This process is called freeze concentration, and it is actually used intentionally in the food and beverage industry as a gentle way to concentrate juices and other liquids without heat, preserving flavor compounds that might break down during evaporation.¹

In a soda can, though, nobody is carefully controlling the process. What you get when you thaw is uneven distribution. The first sip might taste intensely sweet and syrupy while the last portion is watery and bland, because the concentrated sugars and the dilute ice-melt portions have not fully remixed. Shaking or stirring the thawed soda helps, but the flavor profile still tends to be “off” compared to one that was never frozen. The sweetness can taste sharper, and the balanced flavor the manufacturer designed tends to fall apart.

Artificial sweeteners in diet sodas behave somewhat differently from sugar during freezing, but the net effect is similar: the drink tastes noticeably different after thawing. Some people describe thawed diet soda as having a more pronounced chemical or metallic aftertaste, though this is partly a matter of expectation and partly a result of losing the carbonation that normally masks those flavor notes.

Is the Container Still Safe After Freezing?

This is the concern that trips up most people. The soda itself is fine to drink, but did freezing do something to the container that could make it unsafe?

Most soda bottles are made from PET plastic (polyethylene terephthalate), which is the same material used for bottled water. PET is designed to handle a range of temperatures and does not leach harmful chemicals when frozen. The persistent internet claim that freezing plastic water bottles releases “dioxins” has been debunked repeatedly by toxicologists and the FDA. Dioxins are produced by combustion processes, not by cold temperatures. PET does not contain dioxins, and freezing does not create them.

That said, if a plastic bottle has cracked during freezing, the structural integrity of the container is compromised. It could harbor bacteria if left at room temperature for a long time after thawing with a broken seal. The safest approach with a cracked bottle is to drink the contents promptly after thawing or discard them.

Aluminum cans are lined with a thin interior coating, usually an epoxy-based resin, that separates the liquid from the metal. If a can has bulged but not burst, that lining is probably still intact. If the can has visibly split, some of the soda may have contacted bare aluminum. Drinking a small amount of soda that briefly touched aluminum is not a meaningful health risk, but the ruptured can should go in the recycling bin.

Glass bottles that survived freezing without cracking are perfectly fine once thawed. Glass is chemically inert and does not change properties at freezer temperatures. The risk with glass is purely mechanical: the bottle shattering and contaminating the soda with fragments.

What Freezing Does Not Do

Freezing does not sterilize soda, but it does not introduce new microbial risks either. Commercially sealed soda is already a hostile environment for bacteria. The combination of low pH (high acidity), high sugar content, carbonation, and the preservatives used in most formulas means that sealed soda is not a food-safety concern before or after freezing. No pathogenic bacteria are going to grow in a sealed can of cola, whether it was frozen or not.

Freezing also does not break down the chemical sweeteners, caffeine, phosphoric acid, or citric acid in soda into anything harmful. The molecules are stable at freezer temperatures. Some flavor compounds are volatile and can be lost when CO2 escapes, which contributes to the taste change, but nothing new and dangerous is created.

One misconception worth clearing up: some people assume that because frozen soda tastes different, it must have “gone bad” in the way that spoiled food goes bad. The taste change is a physical rearrangement, not chemical decomposition. The sugar and acid are still there; they are just distributed differently and the fizz is gone.

Dental Erosion From Frozen Acidic Drinks

There is one health angle that gets overlooked in the “is it safe” question. If you are drinking soda in its partially frozen or slushy state rather than fully thawed, there is reason to think it could be harder on your teeth. Research on frozen fruit juices found that the frozen versions had higher titratable acidity and caused more calcium to dissolve from tooth enamel than their unfrozen counterparts. Frozen acidic drinks also had greater buffering capacity, meaning they resisted the neutralizing effect of saliva more effectively, prolonging the acid attack on teeth.²

The reasoning applies to soda as well. Soda is acidic (a typical cola has a pH around 2.5), and freezing concentrates the acids in the same way it concentrates the sugars. Sucking on a frozen or slushy soda means your teeth are exposed to that concentrated acid for a longer period than they would be if you just took a normal sip of a liquid drink. The study on fruit juices concluded that sucking on frozen acidic beverages is more damaging to enamel than drinking the same beverages in liquid form.²

This does not mean you should never eat a soda slushie. But if you already have concerns about enamel erosion or sensitive teeth, it is worth knowing that the frozen form is likely worse for your teeth than the liquid form, not better.

Making Soda Slushies on Purpose

Plenty of people freeze soda intentionally because they want that slushy texture. The trick is to avoid the exploding-can problem while still getting the drink cold enough to partially crystallize.

The safest method is to pour the soda into a freezer-safe container with room for expansion, leaving at least an inch of headspace. A wide-mouth plastic container works well. Put it in the freezer for about two to three hours, checking periodically. You want a thick, icy slush, not a solid block. Once the soda is frozen solid, it is much harder to get back to a pleasant texture.

Another popular method involves chilling an unopened bottle of soda in the freezer for roughly ninety minutes to two hours, just long enough to get it well below freezing without actually crystallizing. When you take it out and open the cap, releasing the pressure, ice crystals form almost instantly throughout the liquid. This works because the dissolved CO2 keeps the liquid in a supercooled state, and the pressure release triggers rapid nucleation. It looks impressive and produces a drinkable slush, but the timing window is narrow. Leave the bottle in too long and you get an explosion; take it out too early and you just have very cold soda.

If you do freeze soda in its original can, the least risky approach is to set a timer for no more than about an hour and a half. That gets the soda very cold and possibly slushy at the edges without reaching the point where expansion cracks the can. Forgetting about it overnight is how most freezer-soda disasters happen.

Why Flat Thawed Soda Still Has Its Uses

If you accidentally froze a few cans and the thought of drinking flat cola does not appeal to you, the soda does not have to go to waste. Flat soda still works as a cooking ingredient. Cola is used in barbecue sauces, marinades, and glazes for its sugar and acidity, and the lack of carbonation is actually preferable in those contexts because you do not want fizz interfering with the cooking process. Lemon-lime sodas work in cake batters and quick breads as a sweetener and leavening helper, though the leavening effect relies partly on carbonation, so a flat version will contribute sweetness and moisture more than lift.

Some people also use flat soda to water plants in a pinch, arguing the sugar feeds soil microbes. Whether this actually helps your garden depends on the plant and soil, and the acidity of cola can be problematic for acid-sensitive species. It is not harmful in small amounts, but it is not a serious gardening hack either.

Frozen soda that has thawed and gone flat is also sometimes used to make popsicles. Pouring it into molds gives you a sweet, flavored ice pop without the carbonation problem. This circles back to the dental erosion point, though: a soda popsicle means prolonged contact between acidic, sugary ice and your teeth, which is one of the less tooth-friendly dessert options you could choose.

When You Should Throw It Away Instead

In most cases, thawed soda is safe even if it tastes underwhelming. There are a few situations where discarding it makes more sense:

Shattered glass: If a glass bottle broke in the freezer, do not try to salvage the soda. Tiny glass fragments can be invisible in a dark liquid and are genuinely dangerous to swallow.
Torn can with long exposure: If a can burst and the soda sat in the freezer exposed to other foods for days or weeks, the flavor will have picked up freezer odors and the soda may have partially sublimated, leaving a concentrated, unpleasant residue.
Opened and refrozen: If you opened a bottle, drank some, recapped it, and then froze it, the reduced carbonation and introduction of mouth bacteria make for a lower-quality starting point. It is unlikely to be dangerous if refrozen promptly, but the taste will be poor and the container may crack more easily with air in the headspace.
Very old soda: Soda that was already past its “best by” date before freezing will not improve with a freeze-thaw cycle. The flavor compounds degrade over time regardless of temperature, and freezing does not reset that clock.

Outside those scenarios, a can or bottle of soda that froze and thawed in your fridge is fine to drink. It will be flat, it may taste a bit off, and it will not give you the experience the manufacturer intended. But it will not make you sick, and the container almost certainly did not leach anything worrisome into the liquid. The worst outcome, in nearly every case, is just disappointment.