Parmesan cheese smells like vomit due to butyric acid, a compound found in both Parmesan and vomit, giving them a similar odor. Additionally, Parmesan may contain isovaleric acid, associated with a “sweaty feet” smell. These acids are natural parts of cheese fermentation.
Is Parmesan Cheese Supposed to Stink?
There’s no getting around it; Parmesan cheese does stink.
However, I know for a fact that some people are appalled by the smell, whereas others love it.
So, whether the smell of Parmesan cheese is offensive or not will largely depend on the individual.
That being said, there is a particular reason that the smell of Parmesan is likened to that of vomit.
This all comes down to the compound butyric acid.
Butyric acid is a carboxylic acid that is known for its foul odor.
The smell is most commonly associated with rancid butter, Parmesan cheese, and of course, vomit.
That being said, if you can stomach anything that contains butyric acid, it has a fairly sweet aftertaste.
Just to make matters worse, there is a different type of acid found in tubs of Parmesan cheese.
You know the ones I mean, the tub or tin that contains granules of Parmesan cheese, typically used to sprinkle over spaghetti bolognese.
Well, it just so happens that the odd smell you get from these tubs of Parmesan cheese is isovaleric acid.
Isovaleric acid is a short-chain fatty acid that generally develops during the cheesemaking process.
Isovaleric acid has an odor that is described as “sweaty feet.”
Plus, it is produced by the bacteria found in between your toes.
So, if ever you hear the smell of Parmesan cheese described as “sweaty feet” or “vomit,” now you know why.
How Can You Tell If Parmesan Cheese Has Gone Bad?
So, Parmesan cheese naturally has an “iffy” smell, but how exactly can you tell whether it’s gone bad?
What I mean by this is that we generally perform a sniff test to check whether a substance is safe for consumption.
However, you’re going to be greeted by a pretty foul smell anyway.
Firstly, Parmesan cheese will typically last around 7-9 months unopened.
The packaging will have an expiry date, so this should be the first place you check.
Once opened, Parmesan cheese will usually last for 1-2 months in the fridge.
That being said, you will need to ensure that it is sealed, and if returning to the original packaging, ensure that you squeeze any excess air out.
I prefer to wrap my Parmesan in tin foil or place it in an airtight container.
Next, you can do the sight test.
Parmesan is usually white or beige, but as it starts to go off, it changes to a yellow or darker beige color.
Furthermore, Parmesan is a hard cheese, but it is often spongy or wet to the touch as it starts to go bad.
You may also notice mold spots on Parmesan, although as it’s a hard cheese, you can cut these out and eat the rest.
It’s only once mold has gone the entire way through Parmesan that it should be thrown away.
Finally, there is a smell test.
Granted, Parmesan may well smell like vomit when it’s perfectly fine to eat, but the smell will be rancid once it has gone off.
How Parmesan Cheese is Made
So, I hope you understand that Parmesan cheese smells like vomit because they both contain the same compound.
The compound in question is butyric acid, which is a carbolic acid most commonly found in butter, Parmesan, and vomit.
Furthermore, shredded Parmesan cheese, typically in cans or tubs, will produce isovaleric acid, which is often described as smelling like sweaty feet.
So, you could say that it’s perfectly natural for Parmesan to stink.
And if you are worried about moldy cheese, read my article on how long Parmesan lasts when it’s opened.
Why do you think some individuals find the aroma appealing while others do not?
Let us know your thoughts in the comments below!