How To Make Blue Cheese Cultures (Penicillium Roqueforti)

In this article you will learn step by step how to make your own blue cheese culture (Penicillium Roqueforti) at home.

The best part?

You will save hundreds of dollars by producing your own Penicillium Roqueforti.

And if that’s not enough…

It allows you to have blue cheese cultures on hand for when you make your next blue cheese at home.

How To Make Blue Cheese Cultures (Penicillium Roqueforti)


Are you a blue cheese fan? Do you love yourself some funky blue mold?

I have to say that blues aren’t my favourite cheese, but I can certainly enjoy the right one when I’m in the mood. I’ve had a couple of blue cheeses that were absolutely delicious, and there are certain times when I crave that extra something in my cheese.

If you’re a blue cheese fan and a home cheese maker, I’m guessing you’re either already trying your hand at making your own blue cheese? Or at least it’s in your future plans.

A lot of Curd Nerd’s are absolutely passionate about their blue cheeses, and are busy perfecting their own versions. Some have great success, others are finding it a bit more challenging. Getting that blue mold to grow as it should is usually the biggest test.

Isn’t it typical that when we don’t want the molds they happily grow, but when we do want them, they often seem to be elusive?


A Great Home Cheese Making Cost Saving Tip

The great thing is that like most cheese types, you can easily buy the cultures you need to make blue cheese. But in another cost saving tip, and so as to provide you with a new cheese making challenge, I want to share a resource with you that tells you how you can cultivate your own free source of blue molds (Penicillium Roqueforti).

While noseying around the internet at what other cheese makers are writing about I found this article about how to make your own Penicillium roqueforti – blue cheese mold.

Now I haven’t tried it myself yet. As I said, blues aren’t my favourite cheeses, therefore I don’t make them often. When I do it’s normally as a gift for my father in law who LOVES a good stinky cheese.

But I’m all for ways to get back to the traditional ways of making cheese, and this ‘recipe’ involves growing your own blue mold spores, similar to how it would have been done traditionally, rather than using a mass produced culture.


How To Make Penicillium Roqueforti Spores

  • It involves leaving a piece of sour dough bread with a pea sized piece of ripened blue cheese.
  • Leave the cheese and bread in an airtight container for two weeks.
  • Monitor the spread of the mold on the bread and flip it every couple of days.
  • Wipe off excess moisture from the container, to avoid the bread going soggy.
  • Once the growth of those special Penicillium Roqueforti spores, has consumed the bread in blueish-green mold the bread is ready to be dried.
  • Leave the container opened for a few days allowing the bread to dry. Ensuring to flip the bread so it fully dries.
  • Once fully dried, store in an air tight jar. The jar does not need to be refrigerated and the penicillium roqueforti spores will last for years.

Recipe: David Asher


Penicillium Roqueforti Make Your Own Blue Cheese Cultures
Photo: Kelly Brown


How To Use Bread Mold Penicillium Roquerforti To Make Blue Cheese

Use a pea sized piece of penicillium bread mold to every 3.7L or gallon of milk. Mix the bread with a quarter cup of water to release the spores. Then pore the water into the milk through a strainer, then simply begin your blue cheese recipe.

Even though I haven’t tested whether this works or not I wanted to share it with you so that you can try it, and perhaps come up with your own world famous blue.

Your family and friends might wonder why you have a stash of moldy bread you seem to be nurturing, but you’ll know the potential that lies within : )

The other thing I love about this method of making your own cultures is that it takes something you can easily get your hands on and with little effort and very little money, soon providing all the Penicilium Roqueforti you want or need.

I love the whole concept of taking one thing and making something just as good or even better as a by product.

And who doesn’t want to save money on cultures? They can be pretty expensive if you’re making cheese regularly.


If you don’t want to make your own Penicillium Roqueforti, you can get it below or in our Curd Nerd Shop.

Do you have any questions or comments about cultivating your own blue mold? Join the discussion over at the Curd Nerd Forum. We would love to hear from you!


Curd Nerd Forum


10 thoughts on “How To Make Blue Cheese Cultures (Penicillium Roqueforti)

  • 29/09/2013 at 10:11 pm

    I tried it few months ago. It works fine.

  • 07/11/2013 at 2:04 am

    I love bleu cheese and did make my own culture. The first one looked a bit sketchy compared to my second one, but I still used it. Now I’m wondering what to do with the cheese if the blue doesn’t take.

  • 26/11/2013 at 11:24 pm

    I made a batch of blue cheese on Saturday using the culture from the sourdough bread.

    It is now Tuesday and I have blue mould developing on the outside of the cheese. Is this normal at this stage?

    I used the recipe from Paul Peacock’s “Making your Own Cheese” book.

    Any help would be most appreciated.

  • 02/04/2014 at 4:07 am

    I tried this recently and it worked pretty well. Initially, on the cheese, there was a growth of what appeared to be geotrichum. That was fine by me though, as it kept away all the other molds until the blue took hold (within 7 days, it had a pretty good growth on the surface). Though I’ve not cut into the cheese yet, from the growth I’m seeing, I would declare it a success. It’s also way cheaper than buying (I have about 2-3oz of powder, which just cost me $5 in amazing rye bread -most of which I got to enjoy – 😉

    • 04/04/2014 at 2:55 pm

      It’s always great to hear from Curd-Nerds who’ve tried the methods we write about and have had success! Thanks for commenting Patrick and enjoy those blues!

      • 30/04/2014 at 5:00 pm

        Glad to see that my technique of cultivating roqueforti is taking off and sending off its spores all over cyberspace. Happy blue cheese making!


        • 18/06/2014 at 10:33 am

          Thanks David. And thank you for sharing your technique so we could share it with our readers : )

  • 04/04/2016 at 7:38 am

    I love Saint Agur cheese anyone know how to make it?

  • 04/04/2016 at 7:42 am

    Do you take the mould off the bread and dehydrate it?

  • 09/08/2017 at 10:47 am

    I bought some nice gorgonzola cheese and mixed it with soured heavy cream for a dip. I was delighted to find it growing new blue mold after a couple of weeks. This was totally unplanned but I am happy! Tastes delish!!!

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