The Dangers of Freezing Carbonated Beverages in the Freezer
When it's hot outside and you suddenly think of that cold, refreshing bottle of Coke sitting in your freezer, you might wonder if it's wise to put it back out. The temptation is real, but there are several factors to consider. Whether you're using a glass bottle or a plastic one, the outcome can be anything but refreshing—especially if you leave it in the freezer for too long.
Freezing Carbonated Drinks: The Dos and Don'ts
Generally, it is perfectly fine to put a bottle of carbonated soda in the freezer for a short period of time. However, if you leave it there too long, the results can be disastrous. For instance, a glass bottle of soda can freeze solid and even shatter, while a plastic bottle may crack due to the expansion of the liquid inside.
The primary issue occurs when the soda freezes. Water expands by about 9% when it turns from a liquid to ice. This expansion can create immense pressure inside the bottle, causing it to break. Additionally, the trapped carbon dioxide gas adds to the pressure during the formation of ice.
What Happens When Soda Freezes in the Freezer?
When a carbonated drink is placed in a freezer, it goes through several changes. At first, the pressure inside the bottle decreases as the temperature drops. This is due to both Charles' Law, which states that pressure is proportional to temperature in a fixed volume, and the increased solubility of carbon dioxide in water as the temperature falls. As you can see from the CO2 solubility curve, the most carbon dioxide can dissolve at higher temperatures.
As the temperature continues to drop, ice begins to form, and the dissolved carbon dioxide starts to come out of solution. This creates an increase in pressure within the bottle, which can be exacerbated by the thermal expansion of ice. At very low temperatures and high pressure, carbon dioxide can form clathrates, or hydrates, which are stable under these conditions.
The phase diagram of CO2-water ice is a key factor in understanding these interactions. The dark gray area V-I-H on the diagram represents the conditions where CO2 hydrates are stable, along with gaseous CO2 and water ice. This can lead to significant pressure increases as the temperature drops and CO2 forms hydrates.
Why Does Soda Explode in the Freezer?
When a bottled soda is left in the freezer for too long, the liquid inside begins to expand as it freezes. This expansion generates tremendous pressure. If the bottle is made of glass, the combination of solid expansion pressure and gas pressure can cause it to explode. In the case of a plastic bottle, while it may not shatter, it can still develop cracks, resulting in a mess in your freezer and on your fridge.
The process of shattering from frozen soda is more than just a inconvenience—it can cause significant damage. The sticky substance left behind from the sugar in the soda can make a real mess, requiring a thorough cleaning to remove it completely.
Preventing Damage from Frozen Soda
To avoid the risks associated with freezing soda, it is best to use a pitcher or a reusable container with a spout, or even better, just consume the drink within a reasonable timeframe before it hits the freezer. If you absolutely must freeze the soda, make sure to leave enough space in the bottle for expansion. Placing the bottle in a plastic bag can also prevent a mess if it does indeed shatter.
In conclusion, while it may seem tempting to use the freezer to chill your soda quickly, the potential for damage to your appliances and a significant mess at the end of it all make it a risk not worth taking. Always exercise caution when dealing with carbonated beverages and freezing temperatures.