When it comes to curing meat, especially dry-cured meat, over a few months or more, interpreting mold growth is one of the more challenging hurdles I’ve encountered when I began learning the craft several decades ago..

The beneficial mold, once nurtured in a conducive environment, will then assist in the more even drying of the cured meat, more on this later.

Once you become familiar with the beneficial types of mold or develop them in your drying area, they eventually start to grow naturally if conducive conditions are present.

I’ve found it easier to inoculate new dry-cured meat in the drying chamber.

When I started dry-curing meats, I didn’t use any starter culture, which is one method for inoculating either the meat or the dry chamber (or both) to create the right environment at the start.

I followed the natural path and was willing to let nature decide whether the project progressed. It was often ‘blooming’ naturally, though I’ve now done it to dozens of drying chambers with some experiences to share. This comes from the meat, although it is invisible to the naked eye before its growth.

Dry-curing meat has been practiced for thousands of years. Hundreds of years ago, it was nurtured regionally in Italy, much like sourdough starter cultures.

Common sense, logic, and trusting your instincts about whether the food is edible will help a lot if learning about the beneficial mold for home-made dry-cured meats.

Examples of Beneficial Mold on Cured Meat

I’ve put many examples of the mold in different projects below to help visualise.

You’ll see that sometimes a casing is used, and sometimes not. Casing slows drying, making it even for many whole-muscle meat curing projects.

Dry Cured Meat Penicillin White MoldPin
An example of a healthy, blooming, beneficial penicillin mold on my dry-cured wild venison “braesola”.
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Close-up of some exotic Asian, Turkish, and Eastern European styles of salami we made.
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Close up to illustrate the beneficial mold appearing on this dry-cured pork in the drying chamber.

Purpose of Beneficial Mold

This helps regulate the drying process of the cured meat

It also gives it a layer of protection. For some, the flavor is another factor that adds another level of complexity.

The goal often, but not for all dry cured meat projects is to develop a good covering of powdery white penicillin mold outside the dry-cured whole muscle meat or dry-cured salami to regulate the drying

If no mold is present, the drying on the exterior of the cured meat can be a lot drier than the centre. The goal is always to dry the meat slowly, so this is ideally avoided. However, most home meat curers will struggle with this. It’s often called ‘case hardening’.

If the exterior gets too dry, it can prevent the moisture internally from dissipating. I’ve never had this occur.

The mold you want for your dry-cured meats can either naturally bloom or be introduced from a commercial culture, which is bought and kept frozen to keep the cultures alive.

It can be a purchased starter culture that you then inoculate with the cured meat and, if you want, the chamber with a few sprays.

For many dry-cured meat projects, the drying phase lasts more than one month. Typically, it takes a couple of days or a week to see mold blooms on meat, depending on where it was hung (chamber/cellar, etc. ). Cold-smoked meats will often have less or no mold growth due to the anti-fungal properties of smoke.

The general environmental factors for getting beneficial mold are temperature, humidity, airflow, existing mold culture that may be on the meat but invisible, and the amount of light (less light the better, since it can make fat rancid over time (no light bulbs, etc, in the chamber).

Main factors being:

Temperature – 50-60°F / 10-15°C

Humidity – 70-80%

Other recipes, such as Calabrian pancetta, are covered with pepper and chili/pepperocino. External spices are used to deter the growth of mold.

Peppercorns and black pepper have antibacterial and antifungal properties.

Flavor of Beneficial Molds

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Early development of white mold

The taste and smell relate to the type of umami or savory flavor.

One of my friends, whom I taught how to dry-cure meat, loves the flavor of that white powdery mold outside his wild pig guanciale.

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Commercially dry-cured meat with a bloom of white mold—you can see the beneficial powdery and fluffy growth. The fluff looks like the camera is out of focus, but it’s not.

Quite a bit of complexity can happen with the smell of salami or a whole muscle piece of charcuterie while it develops; this is why I find this craft so fascinating!

Here is a video I made about Salami cured meats and mold:

Natural vs. Lab-Created Mold

Supposedly beneficial mold is on many meats and foods. This is why I’ve had several drying fridges naturally create types similar to the common – Penicillium nalgiovense.

Depending on your environment, your piece of meat may have a chance of the naturally occurring penicillin starting to grow on it. I’ve done this several times over the years with new DIY meat curing chambers I’ve put together.

But of course, this is not guaranteed.

Commercial producers of dry-cured authentic salami, which takes months, not the tangy acidic stuff made in a few days, often use this culture to ensure consistent outcomes.

They buy stuff and inoculate the salami or whole-muscle meats themselves.

Mold 600 – Bactoferm

Home charcuterie makers and many other producers use CHR Hansen Mold 600 for whole-muscle meat curing inoculation.

There are plenty of starter cultures, but many perform a similar function for salami: acidification (a key tool for preserving salami and creating good outcomes). That’s more for international acidity increase (another way to preserved the salami).

Mold 600 is more about the exterior of the meat/casing while it’s drying.

I have it sitting in my freezer now. You can’t get it in every country, but most countries in the Western world do. It probably has other names.

Guys have contacted me through the blog about trying to ‘scrap’ commercial traditional salami they buy to inoculate their DIY curing chambers!

I take half a teaspoon to half a cup of water when using it. The water should ideally be distilled, but I’ve used filtered water, which has also worked.

Then, after giving it a shake, you leave it on the bench for eight hours and spread it in the chamber onto cured meat. Within a few days, you should start to see the spores of white mold developing.

Here is a link to bactoferm Mold 600 on Amazon.

Beneficial White Molds Will Age into Green Molds

Many people talk about powdery mold, but when you start learning more about dry-cured meats (here is a page on all the guides on this site), you’ll notice that at first, you might get fluffy mold.

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An array of Good Mold!

But really, underneath that fluffy white mold is powdery mold. It’s just the way that it grows.

Then, as the mold ages, there is a green mold related to the spores of the white penicillin mold. What I’ve noticed is that the smell of this green mold is pleasant.

The above picture shows well-developed green mold in a commercial environment in Lavasi, Calabria, at the bottom of Italy.

Removing Mold From Cured Meat

Ways of Reducing Mold on Cured Meat:

  • Acidity (vinegar)
  • Cold Smoke
  • Lower Humidity
  • Lower Temperature

These methods can assist when drying meat and preventing too much mold, which is beneficial mold. I’ve been to commercial Artisanal producers, often wiping and brushing the excess mold.

If there is excess mold, a soft bristle brush is often used first to remove most of it.

The easiest way to remove white mold or any other mold from the meat is to use vinegar’s acidity. White vinegar works effectively, but flavored vinegars like malt or red wine are also suitable.

It’s not noticeable, I’ve found, when wiping off the vinegar in terms of flavor.

Vinegar diluted to a 50:50 mixture can also be used. Wiping with a rag or cloth will remove most of the mold. Then, hang the meat again to dry.

If the mold is excessively growing a soft brush can be used also that is sterile.

I have had some funky molds going on. Here are a few examples of things that were not good, not bad, but also what you don’t want.

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WIpe off with vinegar.

When you’re using no casing and going natural, which I often do because I like to see exactly what’s going on, using vinegar and wiping the mold off or even giving it a blast of cold smoke for a few hours can knock back some of this unwanted multi-colored mold.

Often, with a homemade drying chamber, using a fridge and thermostat controls, you are able to tweak the environment to benefit the balance of the mold. Here is another article I wrote on drying chambers

Unwanted Mold – Black

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Examples of fuzzy beneficial mold and green mold .
BUT the black mold in the centre is 1 of 2 pieces I have thrown out over a few decades of making dry-cured meat.

There is a particular ‘off’ smell and a moist-looking black mold that I’ve only had a couple of times over a few decades: the ominous black mold.

It looked slightly translucent and was caused by some exotic spices I used, possibly. I do not know whether this was a factor.

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Spices like star anise, coriander, cumin, and galangal were used. And there was this mold patch of what I would consider very unwanted off-mold.

The smell was very off-putting, and my olfactory (sense of smell) system instantly said it needed to go straight into the rubbish bin.

We have an evolutionary, naturally developed ability that may help us determine whether food is edible. Smelling and looking at it closely can be helpful.

I often get close to my homemade dry-cured meat with my nose and sniff vigorously. This usually gives me an indication of how the meat is progressing.

Charcuterie Salumi Dry Cured Meat PicturePin
Charcuterie, Salumi, Dry Cured Meat – from my standard kitchen fridge. Only a 1-month project, and no mold. The lower temperature and humidity in a regular fridge aren’t ideal for mold or drying cured meat, but can work for small pieces under 300 grams that are lean.

Put differently, if you have any doubts about anything you’re making, it’s not worth getting sick from, and you should always be on the side of conservatism. After decades of making dry-cured meats, I’ve only twice thrown out meat.

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Cold-smoked Dry-Cured Bacon after 2 months in the curing chamber. There is no mold because it has been cold-smoked and then hung to dry.

I’ve also noticed that when I had a dry curing chamber power cut, it reset to a fridge temperature. The hanging Hungarian salami did have some white mold since I didn’t notice the wrong drying temperature.

I changed it back, and after a day, the white mold was gone (back to 12C or 55F approximately). Lower temperature could be used to knock back mold that isn’t wanted!

FAQS

Can you eat mold on dry-cured meat?

If it is beneficial mold, it is edible – often it is a mushroom with an umami flavor.

What is the white powder I see on my cured sausage or salami?

That’s likely beneficial mold, often Penicillium nalgiovense or similar strains. It’s intentionally added or can naturally develop during the drying phase. It can help with flavor development, prevent harmful bacteria, and control drying.

Should I be concerned if I see green or black mold?

Yes, you should be concerned. Green can potentially be a well-developed, beneficial mold. However, black mold may signify spoilage and potential mycotoxin production. It’s best to discard the affected meat.

What causes undesirable mold to grow on cured meats?

Factors like salt curing/spice mix, improper humidity, lack of air exchange, lack of air flow, or temperature.

How can I prevent unwanted mold from growing on my cured meats?

Maintaining control over temperature and humidity during drying phase. Using proper starter cultures and ensuring good hygiene during the process also helps.

What does “blooming” mean in the context of mold on cured meat?

Blooming refers to the healthy and even growth of the desirable white mold on the surface of the cured meat.

How should properly molded cured meat smell?

It should have a pleasant, slightly earthy, and characteristic aroma of the meat and spices. Mushroomy, Uamami and savory like smells.

What should properly molded cured meat feel like?

The surface with the white mold should feel dry and slightly powdery. Slimy or sticky textures are signs of spoilage.

How should I store cured meat with mold?

Store it in a cool, dry, and well-ventilated environment, ideally within the temperature and humidity ranges recommended for that specific type of cured meat. For longer-term storage, you can use vinegar/acidity to clean off the mold, let it dry uncovered in a fridge, then vacuum pack.

Where does the beneficial mold come from?

It’s either naturally present in the curing chamber environment or, more commonly, introduced as a starter culture, after curing, during fermentation, and before or during drying.

Are there different types of beneficial mold used in curing meat?

Yes, Penicillium nalgiovense is the most common, but other strains like Penicillium candidum might also be used.

How do commercial producers ensure the right kind of mold grows?

They use controlled environments with specific temperature and humidity levels and introduce specific starter cultures of beneficial mold. The existing drying environments often harbor the benefitical molds also.

What should I do if I’m unsure about the mold on my cured meat?

When in doubt, it’s always best to err on the side of caution and discard the meat. Your health and safety are the priority.

A pensive chef in a striped apron holding up a grilled rib, seeming to contemplate the quality of his barbecue masterpiece.

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31 Comments

  1. Perhaps you can help. I am curing some pepperoni in UMI BAGS. Been in refrigerator since 3/22. It is now 0.71 its original weight. I noticed some white spots with green in the middle of each dot. Should it be discarded? New at this so a bit insecure. Do you have any advice?

    1. Hey there,
      often I find white and green completely fine, have a sniff! can wipe with vinegar if you want. You’ll find out when it’s done! Nothing is guaranteed with dry curing, thats why i love it!

      1. I am having the same thing. .79 weight loss using the dry aging bags, and I have a bunch of good white mold showing, but some spots 1/4 inch across that have a grey/green/blue color to them in the center of the dot. If you email me directly, I can send you a pic.

        1. Havent tried those bags, but been talking to some of those companies to see if I can test them. Your Nose will also indicate the molds that you want or not. Wipe with vinegar if its on the outside Cheers Tom

  2. Hello, I’m trying to make my first pancetta. After some time in the fridge, and a few days of my abscense it developed white mold like this:
    https://imgur.com/GypQ4He

    I asked around and some people told me to wipe it with some vinegar, after the process it looks like this:
    https://imgur.com/m8aByb6 https://imgur.com/YkaugKk https://imgur.com/xfmrm1t

    I’m not sure about the dark spots, do you think is okay or should i throw it out? The meat itself smells fine.
    Best regards

    1. Howdy Jan
      Always hard to judge this type of thing from pictures….
      How Does it smell? like you want to eat it or not?
      What method of curing the meat did you use, eq curing? %’s?, time in cure? how long in cure?
      Where was it dried and what temp, humidity and airflow?
      how firm was the meat after curing?
      There are plenty of cuts/crevices in the meat, did you put dry cure in these?
      White mold is of course what you want, so what did that white mold smell like?

      It doesn’t look like it has lost 30%+ weight, did it?
      I have a course also about whole muscle dry curing here
      All the best
      T

  3. So just checking we have some speck that was probably stored incorrectly and I think it was sweating now it has white and green mold on the surface and smells funky. Can I was it off and cut the outside and eat it? Or is the smell test saying no?

    1. Hey, I can’t do the smell test for you đŸ™‚ In my experience, white/green like what I show is a good mold. But you have to make the call on that one. People always think dry cured meat belong in fridge, if uncovered the dry environment dries it out fast. If it’s in a container, I have had the same, moisture can create issues.
      It best to actually just hang it somewhere around the house in a temperate environment. Like an Italian deli! All the best, Tom

    1. Interesting, email me a pick if you want. But honestly, I haven’t ever got yellow mold. Over the years, many say all is good as long as it’s not black! đŸ™‚ trust your senses! Cheers Tom

  4. Hi Tom,

    Thanks for everything you put up her, its so helpful!
    I have just got some coppas out of cure and want to briefly cold smoke them before putting them into my maturation chamber. Will the low pH of the smoke permanently stop the growth of mold once the meat is in the chamber or will it just delay it?
    Cheers

    1. Hey no worries,
      I’ve found, the cold smoke definitely knocks back mold. I recently had cured pork belly/pancetta I decided to cold smoke for 2-3 hours before hanging. But I lay the pork belly on a rack. It didn’t grow nice white mold where the meat was touching the grill and not exposed to the smoke! That was interesting indeed. Dry out for a bit of a pellicle if need be, before cold smoking. Tacky dry outside allows smoke vapor to adhere to it more! Cheers Tom

  5. Hi Tom. Great insight here and I’m just finishing my first batch of salami. The white mold has turned green on a few which I’m ok with but on one or two it’s turned into a pale pinky colour. Doesn’t smell off in anyway. Thinking I should wipe it off and see what it smells like when sliced ? Have you come across this before?

    1. Thanks! What in the recipe? I’ve sometimes got a bit of pinkish kind from humidity being too hight. I just wiped it off with a dap of vinegar! Want to encourage that ‘good’ mold! đŸ™‚ Cheers Tom

  6. Hi Tom, i did a Dry Aged rack of pork and on the outside i noticed some green on the pellicle, i trimmed it off because it was todays deadline 28 days, the colour is promising on the inside but i’m concerned that the mold affected the whole meat. Look foward to hearing your answer.

    1. I am talking cured meats in this post not dry-aged, so meats that are fully salt-cured. I have a dry ager but haven’t tested it out. Watch this space! It has dry curing functionality which I am currently using.
      How does it smell? That’s the first thing, if it was smelling ok, I would chop off the green.
      In this post, I am talking about advanced penicillin white mold, which is green. Not sure how this relates to dry aging.
      Sorry, but dry-aging is not what I do, I wet age wild meat normally like venison.
      All the best,
      Tom

  7. Hi, I’m not a meat curer! I bought serrano ham last year december ’21! it didn’t get eaten, it was stored dry. Then we cut it but my husband decided he didn’t want it as he was put off by the leg. I then cut it up in January ’23 in smaller pieces and stored them in mylar bags. I went to check on them just now and they have a film of wite mold. I kept it for the dogs, as treats, but not sure now if it’s safe. How long will it kerp and is that slightly slimy white mold safe? ( Iwill scrape it if it hasn’t spoiled the meat) is there another tip how I can find out if the meat is safe? Thank you

    1. Was it vacpacked in the bags? was it stored in a fridge? if yes and yes if yes, i would eat it.
      I wouldn’t give much at all to animals since the salt content is a bit high for the poochys
      ps. some serranos are dried for 5 years!
      Cheers
      T

  8. Hey tom its jono from Pici and we picked olives with Jane in puglia i cant find your new number flick me a txt on 0224344519 for a catch up

  9. Hi Tom. Thank you so much for this article and pictures – incredibly helpful! I am curing my first lonzino and have some fluffy white mold just now starting as I’m at about .75 of original weight. I understand from this that the white fluffy stuff is good, but do I just let it continue to progress or do I wipe it off with vinegar and let it start again? Also, do you typically wipe it all down with vinegar at the end of the cure before vacuum sealing? Thanks so much!

    1. Heya, if its cased, I am not too worried until dried enough. If not cased you could brush it off or wipe it down. always I like to have a sniff and see it the mold smell appealing.
      I’ve definitely learnt that taking off the mold with vinegar is best, the mold can change flavors if infused inside the vac pack. All the best, Tom

  10. Hello!

    I want to express my gratitude for your assistance—it has been immensely helpful!

    I recently cured bresaola and have some reservations about its safety for consumption. Allow me to describe the process and share some pictures:

    I began with a 2.1kg piece, trimming some fat, and then divided it into two portions: 1) 960g and 2) 880g.

    For the curing, I utilized 500g of sea salt and spices, placing the meat in a zipper bag in the fridge for 7-9 days. During this period, I flipped and massaged it daily. Afterward, I washed it with fresh water, followed by a half cup of red wine and the addition of spices. I then wrapped it in cheesecloth and hung it in the fridge. Around two weeks later, white mold covered most parts, emitting a great aroma. After a month of hanging, I noticed an abundance of green mold alongside the white mold, indicating poor airflow and humidity in the fridge.
    *Please copy and paste the url to see the images, Not sure why they are not working as clicks.

    1. https://imgur.com/GrquL6h – * Unfortunately, I did not take a picture of my real moldy meat, It looked something like that.

    Realizing the issue, I unwrapped it and discovered a fair amount of green mold on the muscle’s surface. I removed it with apple cider vinegar, rewrapped it in a new cheesecloth, and relocated it to a basement with 50% humidity and a temperature of 18-20 degrees Celsius. Approximately two weeks later, the muscle appeared dry without any visible molds. It lost around 40% of its original weight, and though there are no visible molds, there are some stains from the scrubbing process. It smells edible from the outside and delightful from the inside, with no signs of mold.

    Ready pictures.
    2. https://imgur.com/JkQDetN
    3. https://imgur.com/g7MzjjY
    4. https://imgur.com/LRUwmXj

    After this detailed explanation (sorry about that), I’m seeking your opinion based on your experience. While I understand you can’t guarantee 100% safety, I would appreciate any insights or advice you could provide. What would you do in this situation try eating it maybe fry it or throw it away.

    Thank you for your response.
    Alex.

    1. Interesting!
      You seem to have thoroughly knocked back the mold, looks great, bit drier on the outside then center, I always say trusty your nose, eyes then if you want your mouth! đŸ™‚
      Send it to me, if you don’t want it!
      Cheers
      Tom

      1. Yes, it turned out very dry.
        Thanks, It sounds like you would eat it, I will try, and if I don’t reply you’ll know why haha.

        Thanks, Tom.

  11. Ah, what a great article! And thank you for the many detailed pictures. I just started learning how to cure/ dry hang and am making Norwegian lamb fenalĂ¥r. I have a little white fuzzy mold and was worried it was going bad. This put my mind at ease, especially since it’s a whole lamb leg. Haha.
    Thank you, again!!

    1. Nice! Thank You. Norwegian flavours are very different! I got a massive Scandinavian cook book from the library and it has some very interesting recipes! All the best, Tom

  12. Hello. Tom. I have read your useful and wonderful writing well.
    I’m drying meat, and mold has started to appear. I’m not sure what to do. If it’s harmful, I’ll throw it away, but if it’s harmless, I want to eat it. The problem is I don’t know whether it’s harmful to the body or not. there is no bad odor. but, there is a funky smell.

    https://imgur.com/a/CBpKRaL

    Thank you for writing such a wonderful post!

    1. Hey there, rub it down with vinegar. I always trust my nose on whether I will eat something or not. Our noses can be very good at telling if something is good or not. All the best, Tom ps. often fuzzy comes from other penniclin based molds, but its always your call.

  13. I made a duck prosciutto with the equilibrium method, cured a couple weeks in the fridge in a vacuum sealed bag, then wrapped in cheesecloth and dried in my mini fridge with a fan, set at 55f and the humidity varied b/w 75-87. I recently cured salami in the fridge with mold 600. I took the duck out every other week and hung in my basement 57f humidity 45-60. When it’d lost 30% I unwrapped it and found some specks of white mold and some dark black patches. It smells fine. I wiped it with vinegar then sliced off the tough dried parts on the meat. It looked bright ruby red underneath the dried dark I cut off. I’ve put it in a vacuum sealed bag in the fridge. I’m concerned about the black spots, which were dry not wet. I have photos but don’t know how to add them to this comment. Any thoughts you have on whether I should eat it or not would be appreciated.