So many of us want to know, what is the white stuff on Cheddar cheese?
I’m sure you’ve seen signs of this white build-up on your cheddar cheese many times before.
You automatically assume it must be mold; therefore, you either cut it off or completely abandon your cheese forever.
But is this genuinely mold?
Is the white stuff actually harmful?
Let’s find out.
The white stuff on cheddar cheese is actually calcium lactate, often referred to as cheese crystals. Calcium naturally builds up on cheddar, and other cheeses, as they age, so this is something that occurs over time. Calcium lactate build-up is completely natural and, therefore, safe to eat.
1. Can You Eat Cheese With White Stuff On It?
So, the white stuff on cheddar cheese is calcium lactate.
This can often be seen in the form of white specs on the outside of your block of cheddar and also in shredded cheddar too.
You could actually say that the “white stuff” is a good sign.
Calcium deposits are typically found on cheddar (and other cheeses) as they age.
In fact, they are even there when not noticeable to the naked eye.
This is actually completely natural and part of the aging process.
Plus, you will come to absolutely no harm by ingesting it, and calcium lactate is, therefore, safe to eat.
This build-up is sometimes referred to as “cheese crystals.”
So, it isn’t a sign that your cheddar has gone off, and it isn’t classed as mold.
Many cheese connoisseurs look out for these “cheese crystals,” as they know it means that the cheddar is well-aged and likely to be more flavorful.

2. How Do You Keep Cheddar Cheese From Molding?
Okay, so we’ve established that the white stuff on cheddar cheese is calcium lactate,
Therefore, it’s definitely not mold as you first may have assumed.
With that being said, this probably doesn’t stop you from worrying about mold.
In fact, you’re no doubt used to purchasing your favorite cheddar and noticing that it does mold.
And more often than not, this occurs well before the use-by date.
So, how exactly do you keep cheddar cheese from molding?
Firstly, it’s important to note that the use-by, expiration, or best-before date, merely gives you an idea of how long your cheddar will last unopened.
However, you’ll typically see “use within 7 days of opening” on the packaging.
In truth, your cheddar may well last longer than 7 days, but once opened, the clock is definitely ticking.
Cheddar cheese, and all hard cheeses, can generally be kept in plastic wrap.
Due to their low moisture content, you’ll usually find that hard cheeses won’t dry out.
This is actually an issue with soft cheeses, which should typically be wrapped in parchment or waxed paper.
Mold does require moisture in order to form, so this is something you need to be wary of.
You’ll also notice that mold on cheddar is typically like a green fur.
So, you certainly don’t have to worry about white crystals.
Another way to check whether it’s mold or calcium lactate is by running a knife over it.
If the white areas are textured, then it’s a completely natural formation.
However, if it spreads, then I’m afraid it’s mold.
What’s the Crunch? Crystals in Cheese
Final Thoughts
So, I hope you understand that the white stuff on cheddar cheese is calcium lactate.
This is completely natural and safe to eat.
These are often described as “cheese crystals” and may even provide a slight crunch to your cheddar.
However, cheese crystals are generally viewed as a sign that cheese is well-aged and more likely to be flavorful.
With that being said, if you are worried about mold forming, then always ensure your cheddar is correctly packaged in plastic wrap.
Furthermore, regardless of the expiration date, most cheddars will inform you on the packaging that it should be eaten within 7 days of opening.
If you want to know more about using cheese within the recommended period, read my article on whether it’s safe to eat Babybel after its expiry date.