Is Wine A Pure Substance Or A Mixture?

A lot of people wonder if wine is a pure substance or a mixture.

A lot of the confusion comes down to some misunderstandings about wine and how it’s made.

In order to fully answer the question, we first need to look at how wine is made, as well as find out if there’s anything else mixed into it.

We should also define what exactly a pure substance is, as we’d need to be clear on that in order to define whether or not the wine is a pure substance or a mixture.

Once we’ve got both definitions, it should become pretty clear as to whether or not wine fits into the definition of a pure substance.

What is a Pure Substance?

A pure substance, is essentially a substance with both definite and constant composition with distinct chemical properties. 

To avoid confusion, in chemistry a pure substance is often referred to as a chemical substance.

Through that definition, we could infer that a mixture is anything that’s opposite to this, i.e., a substance which changes composition over time.

To make it even simpler, a pure substance is anything composed of a single type of material.

In other words, it is free of contaminants. So, in addition to elements, compounds, and alloys, a pure substance might include honey, even though it consists of many types of molecules.

Examples of a pure substance can include, but isn’t exactly limited to:

Where one might think that wine is a pure substance lies in the fact that ethanol can also be considered a pure substance.

As this is the active ingredient in alcohol, it might be the reason why so many people think that wine is also a pure substance.

However, as we demonstrate further below, this might not actually be the case, or at least, it isn’t with wine.

As for a little bit of reference, some examples of mixtures can include the likes of:

How is Wine Made?

Wine goes through what’s called a fermentation process.

Fermentation is when sugar from fruit, in this case, a grape, is converted into alcohol (ethanol) and carbon dioxide.

In most cases, the fruit needs to be crushed and then the yeast is added. However, with grapes, it’s slightly more complicated than that.

You see, grape juice and sugar are located on the inside of the grape, whereas yeast is abundant in the skin of the grape.

The grapes naturally start to ferment as soon as they’re crushed, as the yeast and bacteria in the grape skins mix with the sugar in the insides of the grape.

As the fermentation process proceeds, the sugar content will gradually reduce to around the 2% range, while the alcohol content will gradually increase to between 9% and 12%, depending on how long you let it ferment for (and the initial sugar levels).

Is Wine a Pure Substance or a Mixture?

All of that may lead someone to believe that wine is a pure substance.

However, what they’re forgetting is that the end product of the fermentation, i.e., the wine, is a mixture of what began at the first stages of the entire process, namely the yeast, bacteria, and sugar that were kept separate in the grape in the beginning.

As we defined a pure substance in the beginning as something that doesn’t change its chemical makeup, then we can rule wine out as a pure substance due to the fact that it changes its chemical composition several times throughout the entire fermentation process.

Therefore, it can be argued that wine is a mixture and not a pure substance. 

Ethanol, a constituent component of wine is a pure substance but wine itself is a mixture.