You’d be justified to assume that ice will float in virtually any liquid, including alcohol. After all, an enormous iceberg in the Arctic has no problem floating on the ocean’s surface. So, why do your ice cubes always sink when you put them into a glass of whiskey?
Ice doesn’t float in pure alcohol as it does in a glass of water. This is because ice is denser than alcohol. However, this is only true when considering alcohol in high concentrations. When looking at alcoholic beverages, it depends on the percentage of alcohol in the drink.
The rest of this article will explain why ice doesn’t float in alcohol in detail. I’ll also answer what type of alcoholic beverages ice floats in and why ice floats in water.
Why Doesn’t Ice Float in Alcohol?
Ice doesn’t float in alcohol because ice has a higher density. Alcohol is significantly less dense than water and ice. However, ice does float in certain alcoholic beverages. Ice can float in beverages with a lot of sugar and other ingredients, such as beer and wine.
There are three different types of alcohol:
- Isopropyl alcohol is commonly found in rubbing alcohol, cosmetics, and cleaning supplies.
- Methyl alcohol is primarily used as an industrial solvent, such as paint remover.
- Ethyl alcohol is found in alcoholic beverages and a variety of different products.
While these are three very different chemicals used in very different ways, they have many similarities. Per Wikipedia, the term alcohol refers to “an organic compound that carries at least one hydroxyl functional group (−OH) bound to a saturated carbon atom.”
The only type of alcohol that is safe for us to consume is ethanol. It’s found in beers, wines, and spirits alike. But the concentration of alcohol is different in each of these drinks.
So how is alcohol different from water?
Ice will not float in alcohol because the molecular structure of alcohol is very different from water. Isopropyl, methyl, and ethyl alcohol have similar molecular structures and are less dense than water. This means ice can’t float in any of these liquids in their purest form.
When considering alcoholic beverages, the science is simple: alcohol and alcoholic drinks contain ethanol.
Ethanol is a naturally occurring chemical compound that is produced during fermentation. Fermentation is a process used in baking and the production of alcohol through which yeasts break down sugars. This process creates both carbon dioxide and ethanol.
Where water is made up of hydrogen and oxygen, ethanol is a hydrogen, oxygen, and carbon compound. Ice has more space between molecules than water, but ethanol has more space between molecules than ice. Therefore, ethanol is less dense than ice.
Does Ice Float in Alcoholic Beverages?
Ice floats in certain alcoholic beverages but not all. Ice can float in drinks with a low percentage of alcohol, like beer, wine, and creamy liquors. However, ice doesn’t float in hard liquors like whiskey, absinthe, and vodka because they’re less dense than ice.
As you already know, not all alcoholic drinks are equal.
Beer is usually carbonated and is far less potent than whiskey. Wine can be quite strong but doesn’t burn like spirits. But what’s the difference?
Both beer and wine are undistilled. They’re made by fermenting grain, grapes, and other fruits to create a variety of beverages.
In general, the alcohol content in these drinks is lower because yeast runs out of sugars to consume after a certain point in the fermentation process. At that stage, the alcohol actually becomes toxic to the yeast, preventing further fermentation.
Beer will have an average of 2%-8% alcohol content, and wine may be close to 14%
Ice can float in virtually all undistilled alcohols. They’re mostly made of water, sugar, and other ingredients, so they’re denser than ice.
On the other hand, distilled drinks have a much higher alcohol percentage. Distilling is the process through which water and alcohol are separated. The mixture is heated up, allowing the alcohol (which has a lower boiling point than water) to evaporate. This is collected into a tube above the tank and cooled, returning to its liquid state.
The end result is condensed alcohol with high ethanol content.
Spirits, such as vodka, rum, and tequila, can have a high alcohol content of up to 75%, but typically the range is between 30%–60%.
Unless the distilled alcoholic beverage is loaded with sugar, ice doesn’t float in them.
Also, if the distilled spirit is mixed with a sugary soda, ice will probably float to the top.
Why Does Ice Float in Water?
If an object is heavy, it sinks, right? We have all thrown stones into a river or the ocean and watched them disappear. We have all dived to the bottom of a pool to retrieve toys that have sunk.
So if ice is solid, it should sink. Except that it doesn’t!
Think about those huge icebergs you’ve seen on TV. They look immense from the surface, and there is so much more under the water. Similarly, picture an ice-covered lake. Why does it sit on the surface and not simply submerge? How is this possible?
In the simplest of terms, ice floats in water because it is less dense. If you were to take two containers, each with the same volume of ice and water, you would find that the water actually weighs more. This is due to the open structure of ice and how it expands upon freezing.
In less simple terms, according to Wikipedia, ice has a density of “0.9167–0.9168 g/cm3 at 0°C (32°F) and standard atmospheric pressure (101,325 Pa), whereas water has a density of 0.9998–0.999863 g/cm3 at the same temperature and pressure.”
Those numbers may look relatively close to the point you could think they wouldn’t make much of a difference. However, those small margins are why we can see a shelf of ice sitting on top of a lake.
How Water Becomes Ice
You can find it in a tray in the freezer, a bag in the grocery store, or even your fridge door. But what is ice exactly?
Ice is frozen water, and water is made up of hydrogen and oxygen atoms. These atoms are bonded and give the water molecules a specific structure. At around 4°C(40°F), water reaches its most dense state, and as it cools further, the hydrogen and oxygen atoms within start to change their behavior.
Water molecules are full of energy and are constantly moving. As the water reaches the freezing point, the molecules inside begin to slow down. Eventually, they will stick together, turning water from a liquid to a solid. Though you might not see it, the molecules are still moving even when frozen.
If you look at alcohol in its purest form, then no, ice won’t float in alcohol. Water, and therefore ice, is denser than alcohol and will sink to the bottom of the glass.
But if you are looking at alcohol in its most common form, then the answer is yes, ice will float in a glass of whiskey and coke or a glass of wine. This is because the ethanol has already been diluted. It isn’t enough to allow the ice to sink in a less concentrated amount.