We were looking for some cheddar cheesein the Wonderopolis refrigerator the other day when we overheard the mayonnaise joking with the mustard.

Mayonnaise: What do you call cheese that is sad?

Mustard: I have no idea.

Mayonnaise: Blue cheese!

Mustard: Don’t quit your day job.

Have you ever eaten blue cheese? It’s often crumbled onto salads or made into salad dressings. It has a unique smell that some people like and others don’t. Maybe its odor offends the other inhabitants of the refrigerator and that makes it sad!

It’s not the blue cheese’s fault, though. That’s just the way that it’s made. Blue cheese — sometimes called bleu cheese (French spelling) — is cheese made from the milk of cows, sheep or goats with the mold Penicillium added.

This special mold creates the unique veins of blue or blue-green mold throughout the cheese. It is these blue veins in the cheese that gave it its name, as well as its signature sharp and salty flavor.

These veins of mold, along with certain types of bacteria, also give blue cheese its special smell. For example, one of the types of bacteria common in blue cheese — Brevibacterium linens — is the same bacteria behind foot and human body odor!

Instead of an invention, blue cheese is thought to have been more of an accident. Over a thousand years ago, cheeses were aged in caves, because their environments were cool and moist. The harmless molds in these caves made their way into aging cheeses and blue cheese was accidentally discovered. Today, many blue cheese makers still age their blue cheeses in caves.

Blue cheeses are unique in appearance because of the veins of mold that run throughout them. These veins are created by a process called needling. Wheels of cheese are poked with tiny needles to create spaces for air. As air finds its way to these holes, it feeds the mold and the blue veins slowly form.

Of course, not all blue cheeses smell and taste the same. Like any cheese product, there are many factors that affect the final product, including the type of milk used, the exact mixture of molds and bacteria and the aging process. Many types of blue cheeses from around the world are considered delicacies.

82 Join the Discussion

1 Star2 Stars3 Stars4 Stars5 Stars  (12 votes, avg. 3.67 out of 5)
    • Hello, Harry! Thanks for visiting Wonderopolis today! We encourage you to explore this CHEESY Wonder to learn what makes blue cheese blue! :-)

  1. I played a game of Jack Bowser where you had to try and crack the code by figuring out the missing word. But he tells you what the word is before you to find, and he’s stuck in a cake instead of being stuck on a tower of cheese.

    • Happy Tuesday, Caelah! Thanks so much for sharing about the Jack Bowser game you played! He’s a cool dog, isn’t he? :-)

    • That’s a very imaginative guess for tomorrow’s Wonder of the Day®, Wonderboy! Thanks for letting us know you enjoyed today’s Wonder, too! :-)

    • You were super close to being the first Wonder Friend to comment on today’s Wonder, Caelah! We think “second person to comment” is really awesome, too! :-)

  2. This wonder was weird. It showed a kid eating blue cheese, but it never explains what blue cheese is. I would of liked it more if you explained how it’s blue. For a suggestion for an upcoming wonder, I think you should a small biography on Michael Jordan.

    • Hi there, brockrock! Thanks for sharing your opinion with us today! The video we include with each Wonder is only part of the Wonder of the Day®! To learn more about why blue cheese is blue, check out the story part of the Wonder, too! There are lots of cool facts and awesome new words to learn by exploring the WHOLE Wonder! :-)

    • Hello, Drake! The “veins” that run through blue cheese are blue, though, and that’s where this awesome cheese got its name! Thanks so much for leaving us a comment today! :-)

    • We’re so glad you enjoyed learning some awesome new things by exploring this Wonder of the Day®, Shaniquia! Thanks for letting us know! :-)

  3. Wow! Your description of blue cheese really makes us want to try it….NOT! We enjoy checking out Wonderopolis every day!

    • Where’s your WONDERful sense of culinary adventure, GM Fabulous 4th Grade? We’re just kidding…we understand that some Wonder Friends might not like the idea of eating cheese with mold in it, but we promise…it tastes REALLY yummy! Thanks for letting us know you guys visit Wonderopolis every day! That makes us SUPER happy to hear! :-)

    • We think it’s really cool that you already knew what makes blue cheese blue, Nicholas! Thanks for leaving us a comment to let us know that! Enjoy your day! :-)

    • We like that guess about tomorrow’s Wonder of the Day®, Stefani and KD! You are both GREAT Wonder Friends for exploring today’s Wonder, too! :-)

    • We agree with you, Gloria…blue cheese is quite tasty! Thanks so much for letting us know you liked today’s Wonder and that you thought it was AWESOME! We think YOU are AWESOME for sharing that with us today! :-)

    • Monsters and vampires sound scary, Jesse, but they’re both something LOTS of Wonder Friends WONDER about! We’ll all have to visit Wonderopolis again tomorrow to see if your guess was correct! :-)

  4. We took a vote and NONE of us like blue cheese! We thinks it’s too smelly. It grosses us out to think that food has bacteria that causes foot and body odor :( A few of our students have never tasted it. Can we get another hint about tomorrow’s wonder, but it might be about bats. Have a great day and thanks for making us wonder!

    • Thanks for always adding something FUN and WONDERful to each Wonder of the Day® you guys visit, Mr. Draper’s class! We like your comments and appreciate them very much! You guys are awesome for sharing what you think about blue cheese today. Sometimes learning about foods is INTERESTING, isn’t it?

      Here’s another hint about tomorrow’s Wonder: FUN + FRIENDS = Tomorrow’s WONDER! :-)

    • It makes us super happy to hear that you learned things you never knew before by visiting today’s Wonder, McKenzie! Learning in Wonderopolis is SUPER FUN, isn’t it? We sure think so! :-)

    • That’s a GREAT question to WONDER about, MW3! We encourage you to explore today’s Wonder of the Day® to find out about some “colorful” streaks or “veins” that run through blue cheese and help give it its signature name! :-)

    • We appreciate you and ALL of our SUPER AWESOME Wonder Friends, McKenzie! All the AMAZING comments you guys leave for us and all the WONDERful things you share make us smile each day! :-)

    • Hi, Ivy! That’s a GREAT question! LOTS of the ideas for our WONDERful Wonders of the Day® come from the amazing Wonder brains of folks just like YOU! By clicking on the “nominate” link that’s found at the top of every page in Wonderoplis and answering a few easy questions, you can let us know what cool things YOU are WONDERing about, too! :-)

  5. I have not eaten blue cheese, but it looks super good and it makes me kind of hungry. (Elijah)

    Thanks Wonderopolis!

    • We’re proud of you for thinking about trying blue cheese, Elijah! We think it’s AWESOME that you and your KF Dragons classmates visited today’s CHEESY Wonder of the Day®! :-)

  6. I think the idea of food in the fridge talking is absolutely absurd, almost like a cat that’s riding a bird. Blue cheese sounds bad, mold growing inside it is part of that. But I may try it out, who knows for sure? It’s just that moldy cheese sounds like it might make you hurl. I’m so sorry about this but I’m all out of time!
    But I’ll be back for the next wonder and my next rhyme! PEACE!

    • We’re super happy to hear from you again, YuGiOhNinja! Thanks for exploring this Wonder of the Day® and sharing your AWESOME rhyme! :-)

  7. Wow! We think tomorrow’s Wonder could be about scary monsters, loud music, nightmares, or barking dogs.

    As for our class, 1/3 of our class has never tried blue cheese. The rest don’t like it except for one student.

    • Thanks for sharing how many of you WONDERful Wonder Friends have never tried blue cheese and how many of you like it or don’t like it, Miss Kirsten’s Kindergarten GT Class! We also like your guesses for what tomorrow’s Wonder might be! You guys are AWESOME! :-)

    • Hi, John! We appreciate your opinion of blue cheese, but we hope you will give it a try someday…it’s really good! :-)

    • We’re glad you left us a comment today, Saad! We hope you’ll re-explore today’s Wonder to find our what makes blue cheese blue…it’s a really interesting process to learn about! :-)

    • Blue cheese dressing is GREAT on lots of things, isn’t it, Zeek? Thanks for sharing that you like it…we do, too! :-)

    • Lots of Wonder Friends really like the taste of blue cheese, Mrs. Wilbanks! We hope maybe you will give it a try one day, too! WONDERing about the way new foods taste is another way to learn about them! :-)

  8. That’s a gross wonder. My brother says that it is good. We have that at home almost everyday. Now I am not going to eat it.

    • Sometimes learning new things about some of the foods we like to eat changes our opinion about them, Emily. A few Wonder Friends also had the reaction you had to this Wonder when they explored past Wonder #14 – Why Does Jell-O Jiggle? http://wonderopolis.org/wonder/why-does-jell-o-jiggle/. We think learning, whether it’s about food, animals, technology or other topics is SO MUCH FUN! We hope you do, too! :-)

  9. Blue cheese is so nasty. I tried it before, but will never try that again! So here is a little tip: never eat it! E.B., A.K.A Purple freak

    • We think some other Wonder Friends just might think blue cheese is AWESOME if they tried it, E.B.! We appreciate your opinion and your comment, though, and are REALLY glad you stopped by Wonderopolis today! :-)

    • We WONDER that about blue cheese, too, Mr. P. and Mrs. Wilwert’s 1st graders! We think it might have something to do with the air holes that are poked into the cheese while it is being made. Didn’t you guys think it was COOL to learn that some blue cheese is made in caves? We sure did! :-)

  10. I did not have a clue that blue cheese was made like that. I also did not know that it was an accident, well I guess I should have, because I don’t think that anyone wold purposely put mold in cheese before they had blue cheese.

  11. First, I want to point out that I do NOT have fish breath, I just like the sound and it is funny.

    Great wonder and such a funny video! Such a cute little baby.

    No idea what tomorrow’s wonder is about. Maybe daylight savings time?

    • It is sort of interesting, we agree, Jaclyn! We think it’s super tasty cheese, though! Thanks for sharing your comment with us today and for exploring this Wonder of the Day®! :-)

  12. My librarian told me you spend hours and hours reading all the comments and answering them. I really want to thank for doing this and I bet all the people that comment thank you, too. I never new so many facts about blue cheese so, thank you so, so, so much!

    • Thanks for being such an AWESOME Wonder Friend, Izzy! We really appreciate your enthusiasm for learning! We enjoy hearing from our AMAZING Wonder Friends (like YOU) and reading their comments…it’s part of what makes Wonderopolis so very WONDERful! :-)

    • Thanks for sharing that you have been eating blue cheese for a long time, Monnie! We think the baby in the video was super cute, too! :-)

    • We think that’s AWESOME, Clayton! Cheese is super yummy and we can DREAM about all the WONDERful foods that feature it, too! Pizza…enchiladas…soup…sandwiches…cheesecake…salads…YUM! :-)

    • We’re really glad you liked the video for this CHEESY Wonder of the Day®, Halei! Thanks for letting us know! :-)

  13. I don’t really like blue cheese.
    But I have wondered what makes it blue. So this was the PERFECT comment!!!!

    Happy Wondering!!!!!!!!!!!!!!!!

    • Happy WONDERing to you, too, Annie! It makes us happy to hear that you learned what makes blue cheese blue today! Thanks for being a GREAT friend of Wonderopolis! :-)

  14. I don’t really like blue cheese. :-(
    But I love blue cheese salad dressing! :-)
    I once saw on a T.V show a person called Ginger
    Fox(She’s a singer)put blue cheese dressing into her hair because she was washing her hair.
    I thought it was gross and hilarious! :-)

    • Some of us here in Wonderopolis like blue cheese, Nabeeha! It’s definitely easy to mistake the two types of dressing — they look alike but taste quite different! Thanks for WONDERing with us! :)

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Have you ever wondered…

  • What makes blue cheese blue?
  • What gives blue cheese its unique smell?
  • How was blue cheese invented?

Wonder Gallery

fruit and cheese_shutterstock_89217121Vimeo Video

Try It Out

Ready to try some blue cheese? Check out the recipes below and pick out one or two to make at home with a friend or family member. You may need to head to the store to pick up a few ingredients before you get started.

Do you have a special blue cheese recipe of your own? If so, share it with your Wonder Friends by posting it on Facebook. We love to try new recipes!

Still Wondering

In The Electric Company’s Jack Bowser: cheese video, special agent Jack Bowser needs to escape, and he needs students to crack the code.

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Wonder What’s Next?

Better get a good night’s sleep! Tomorrow’s Wonder of the Day might keep you awake all night!

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