40 replies to this topic

[Chris Amirault]

My battles with green mold are well documented here. For example, I present a few sticks of particularly memorable sopressata:



Following the advice of basically every book ever published in English on the subject, in which green mold = deadly, horrible failure, I tossed them out. There are a few exceptions out there; members here mention washing it off and rehanging it, but only at the early stages.

Shortly after that disappointment, I went to Barcelona, where I had this experience:

While I was checking out the back room of a local charcutier who was taking care of the hams and sausages, I saw him grab a link of the dry-cured sobresada that was covered with the infamous green mold, grease up his hands with some olive oil, and rub the thing down with the oil. He then wiped it off a bit with a paper towel and put the sausage back in the display case. He proceded to do the same thing to the other sausages, most of which were just white-mold-y. When I asked the only person there who was fluent in English what was up, he shrugged and said, basically, that that's what's done. No muss, no fuss. 

Still no answers.

Fast forward to August 2009. Chris Hennes and I are hitting the outer boroughs in search of good food, and we arrive here.



The justly famous Calabria Pork Store, on Arthur Avenue in the Bronx. The place is the holy shrine of cured pork on the east coast, and it smells hog heavenly. Hundreds of sausages, sides of pork, hams, you name it are hanging overhead.



However, when you walk a bit closer to the product, you see this:





These sausages weren't speckled with green mold; they didn't have a bit here and there. Most of the product in room was coated 40-50% with fuzzy, green to blue mold.

Our jaws dropped. We asked the counter person three or four different times what the story was, and he looked at us like we were nuts. We got the sort of reaction you'd get if you tried to ask a crab on the ocean floor why it was so humid around here.

Meanwhile, Hennes and I ate about as much of the free sample plate as we could eat without being arrested. The stuff is fantastic: funky, rich, deep flavor that only the best cured pork gets. And we're not dead.

Something, clearly, is going on, and I'm hellbent on getting to the bottom of it. Here are my questions: 1. What, exactly, is this "fuzzy green mold"? What distinguishes "fuzzy green mold" from "chalky white mold"?
2. What effects do these molds have? How do you determine which effects are detrimental, beneficial, or both?
3. If, as all the books indicate, this "fuzzy green mold" is so terrible for you, why in the world is a premier salumeria displaying it overhead for all the world to see?
For starters, does anyone have any access to actual facts?

[David A. Goldfarb]

As I recall from my friend whose father made the best sweet sopressata I've ever eaten, he said the salamis would become completely covered in mold in the cellar and would be rinsed in a barrel of vinegar when they were ready to come down.

If you're still in town, try to get to Esposito's Pork Store in Carroll Gardens, Brooklyn (on the F train) for more excellent sweet sopressata and other items. It's a great neighborhood, changing rapidly, but there are still a few good Italian places left that compete over how many times a day they make fresh mozzerella and will ask you, "It's still warm, is that okay? Can I give it to you in the water?"

[slkinsey]

As far as I know, the common mold that grows on the exterior of fermented cured sausages is from the penicillium genus. These can be white, but the fruiting bodies are frequently green.

In Salumi: Savory Recipes and Serving Ideas for Salame, Prosciutto, and More, author Joyce Goldstein writes:

. . . The moisture continues to reduce and the characteristic -- and vital -- penicillum mold begins to grow on the exterior of the casing.  This mold, called fiore, or "bloom," in Italian, acts as a natural antioxidant and protects against rancidity.  As long as the mold is present, the rich flavors of the meat will continue to develop.  This is whty the mold on the most authentic salame is always kept intact until serving, and why it would be rare to find an Italian eating a product without mold.

Every traditionally cured salame generates a mold on the outside of its casing during fermentation and aging.  While modern processors employ science to maintain an aesthetically pleasing white mold, nature on its own will normally generate an artist's palette of colors.

Edited by slkinsey, 06 August 2009 - 07:49 AM.

[dougal]

I've taken it that there are many many potential moulds.

And that while nothing that is chalky and white is likely to be detrimental, there were at least some things that were green and hairy that were unwholesome.
Hence by avoiding the hairy green stuff you avoid the potential risk - even if this is at the cost of excessive caution.

Again my understanding has been that the hairy moulds are at home in rather higher humidity than is good for the sausage. And hence that they are an indicator that a little more air circulation and a little less humidity could be employed.
What sort of temperature and humidity was that shop running at? (August, Bronx ... aircon!)

Not too sure about wiping the sausage down with oil ... but vinegar (ie acidity) seems to be commonly employed.
ADDED The chalky mould is supposed to be favoured in acid conditions, hence it being a helpful indicator of the acidity (and hence c. botulinum freedom) of the sausage. (Or the frquency of its vingar rub!)

Edited by dougal, 06 August 2009 - 08:15 AM.

[Chris Amirault]

So: does this mean that the colors indicate fruiting of beneficial mold (which in turn may indicate an insufficiently dry environment)? In addition, is it appropriate to say that you don't want to eliminate the mold but rather wish to curb the fruiting?

And that while nothing that is chalky and white is likely to be detrimental, there were at least some things that were green and hairy that were unwholesome.
Hence by avoiding the hairy green stuff you avoid the potential risk - even if this is at the cost of excessive caution.

dougal, do you have details on this? What are the "green and hairy" things that are unwholesome? Perhaps "green and hairy" is a both state of beneficial mold and a kind or state of unbeneficial mold.

What sort of temperature and humidity was that shop running at? (August, Bronx ... aircon!)

All a guess, but I'd say that it was about 65F in there, notably chillier than the other A/Ced shops, and about 50-60% humidity, notably drier than on the street (90F & 85ish% humidity iirc).

[dougal]

I'm not any sort of microbiologist, but my presumption has been that avoiding "hairy moulds" should keep you away from unhealthy organisms. For example, there are some of the Aspergillus group that are definitely not at all good for you - notably A. flavus and A. versicolor.
My mycology has been principally the recognition of good edible wild mushrooms rather than id-ing moulds!

Most people shy away from eating visibly mouldy food (with the possible exceptions of cheese and cured sausage), hence much of the health info relates to the effects of inhaling high concentrations of mould spores.
However, as general advice goes, Nanny saying "Don't eat that, its mouldy", was pretty reasonable.
Its just that there are some specific exceptions ...

While the chalky mould is reputedly nothing but good (even discouraging harmful moulds), there are many others that could 'spoil' the food, overlapping into those that are actually harmful.
Even if there are others that can look fierce and yet be benign.

My supposition would be that the "Pork Store" has developed, over the years, a useful collection of fungal 'helpers' which to a large extent police their own ecosystem. Just one of the benefits of having a tradition!

[Chris Hennes]

One thing was clear from our visit to Calabria: the blanket statement given in all of the books I have read that green mold and fuzzy mold are categorically bad is false. As far as I can tell, right now we are all at the point of pure guesswork. The guy at the counter had literally no clue what we were talking about when we suggested that maybe there was something wrong with that mold, and clearly the NYC health department feels the same way (it's not like they hide the Sopressata when the health inspector visits).

I certainly cannot tell the difference between a good mold and a bad mold on sight, and I am loath to throw away any charcuterie on the basis of the mold's color at this point (I'm not sure how clear it is in those pictures, but the green mold was certainly not uniform, there was a whole range of greens/blues going on in there). The store is obviously not a carefully controlled environment, considering the large amount of foot traffic through there introducing who knows what kind of mold spores into the place.

All that said, there are all these published books with the same basic advice in them. Where is it coming from? How real is the danger? How can you tell if you've got any bad mold?

[dougal]

... How can you tell if you've got any bad mold?

Chris, the point is that one can't. Not without a microscope, a lab, etc.

Precise mushroom ID can be hard enough.
I think that moulds generally are pretty well impossible by the naked eye.

Without knowing its safe, the sensible thing is to condemn it.
Because the dangers are real...




There are some interesting illustrations to be found here:
http://www.mycolog.com/chapter20.htm
http://www.mycolog.com/chapter21.htm
Of particular interest are the illustration of the cheese (on the first linked page) with "various species of Penicillium" and (on the second page) the comments above and below the photo of fluorescence (which indicate the risks from A. flavus, and that Penicilliums are not universally benign).

And there's this FAQ

Why is mouldy food dangerous?

You should not eat mouldy food because it may contain poisonous substances that are produced by the moulds.

Many species of such common moulds as Penicillium and Aspergillus, Alternaria, Fusarium and Cladosporium (blue, green, yellow, pink, red or black moulds) which often grow on bread, cheese, fruit and vegetables, produce these poisons, which are called mycotoxins.

We already know of over 200 kinds of mycotoxin, produced by about 150 different fungi, and more are being discovered every year. Some are toxic at very low doses, and many are heat stable, so you can't get rid of them by cooking the food.

Aflatoxin, produced by a few species of Aspergillus, is the most carcinogenic (cancer-causing) substance known. Ochratoxin, produced by other species of Aspergillus, can cause fatal kidney disease. Don't take a chance -- don't eat mouldy food.

http://www.mycolog.com/molds.htm

And Mycolog would appear to be an authoritative source ...
http://www.mycolog.com/bryce.html
http://books.google....tional&resnum=4



About the only thing you can say is that if the mould on the sausage is white and matted ('chalky'), that should be OK.

Otherwise - unless you are certain that it comes from good stuff that you the producer introduced - then its a total "don't know" and an unknown chance of significant harm.

[Chris Amirault]

Thanks, dougal. From this should we conclude that NY should close that shop as a carcinogenic health hazard?

[U]nless you are certain that it comes from good stuff that you the producer introduced[.]

Your references would suggest that certainty is impossible. Or am I missing something?

[jackal10]

I thought the main danger was not molds but the bacterium Clostridium botulinum, that can cause botulism. (botulus = latin for sausage). Keeping the sausage acid, either through ingredients like wine or vinegar, or from lactobacillus fermentation is a countermeasure.

Myco toxins are rare, and like aflotoxin more common from cereal orign rather than meat.

[mkayahara]

I thought the main danger was not molds but the  bacterium Clostridium botulinum, that can cause botulism. (botulus  = latin for sausage). Keeping the sausage acid, either through ingredients like wine or vinegar, or from lactobacillus fermentation is a countermeasure.

Myco toxins are rare, and like aflotoxin more common from cereal orign rather than meat.

Yes, botulism is a big concern with dry-cured sausages, which is why you acidify and use nitrates in them. But some molds can raisee the pH of the sausage, opening up botulism as a risk despite these precautions.

[dougal]

...

...
Otherwise - unless you are certain that it comes from good stuff that you the producer introduced - then its a total "don't know" and an unknown chance of significant harm.

Your references would suggest that certainty is impossible. Or am I missing something?

By mentioning 'producer-introduced' I was referring to the practice of spraying (or dipping) the sausages with a solution (or rather suspension) of your chosen mould. (Or otherwise transferring it!)

Maybe easiest to refer back to our discussion of (was it really?) a couple of years ago ...
http://forums.egulle...dpost&p=1210816 (and subsequent postings)

While searching for that, I chanced to find that Bactoferm M-EK-4 (one USA commercial chalky mould) is seemingly now called "Mold 600" and that the Butcher-Packer site requires some sort of download before permitting any access ...


Regarding any relationships between Italian-American meat processors and public authority officials, I really wouldn't know, since I have not watched The Sopranos.

Edited by dougal, 07 August 2009 - 07:22 AM.

[Chris Hennes]

Perhaps we're taking a backwards approach here. It is certain that there is a non-zero probability that your next sausage will kill you, mold or no, white or green, etc. We introduce nitrates and acidifying bacteria to reduce to the risk of, for example, botulism, to acceptable levels. It seems clear that either there is a massive world-wide conspiracy to allow places like this to remain open despite the rampant danger of killing all of their customers, or that the dangers of unknown mold spores killing you is being dramatically overstated in the literature. As Charcuteriers, what (if anything) do we need to do to reduce the risk of mycotoxin-producing molds to acceptable levels? Has anyone with a mold growth problem considered having the end product tested for toxins?

[dougal]

... what (if anything) do we need to do to reduce the risk of mycotoxin-producing molds to acceptable levels? Has anyone with a mold growth problem considered having the end product tested for toxins?

"Some Factors Influencing Aflatoxin Production in Fermented Sausages"
http://www3.intersci...ETRY=1&SRETRY=0

Edited by dougal, 07 August 2009 - 09:15 AM.

[Chris Hennes]

Thanks, that's excellent. For those without access: the authors deliberately inoculated summer sausages with Aspergillus flavus, a mold that is known to produce aflatoxins, then stored it for six weeks at two relative humidities and two temperatures. They then took a series of measurements of the aflatoxin production.

A few choice quotes from that article (Alvarez-Barrea, et al., "Some Factors Influencing Aflatoxin Production in Fermented Sausages." Journal of Food Science 47(6), pp. 1773 - 1775):

After 6 wk storage at 10°C, no aflatoxins could be detected in any of the samples except for the inoculated-unsmoked sausages held at high relative humidity (89%).

There was, however, no evidence that pH affected aflatoxin production. Davis et al. (1966) concluded that pH did not influence either mold growth or aflatoxin production, as long as the pH was higher than 4.0.

[T]he fact that aflatoxin Br was produced whenever favorable environmental conditions were present suggests that curing ingredients do not have a major inhibitory effect upon aflatoxin production.

So, from this article it seems that it's all about the environmental conditions: after six weeks at 10°C and low relative humidity (79% was the "low" humidity level) there was no aflatoxin production, even when inoculated with mold known to produce the toxin. At high temperature (30°C, but "low" humidities) after six weeks there was production in the inoculated sausages, but not the uninoculated (both were covered with mold). After only three weeks, however, only the high-temp/high-humidity combination produced aflatoxins on the inoculated sausages.

[dougal]

http://bib.irb.hr/da...ry_sausages.pdf

Interesting (pdf) paper.

Northern Italian sausages. 100 artisanal and 60 industrial.

757 different strains of mould identified.

Ochratoxin A ("OTA") was identified in 45% of the samples. (This seems to be the ONLY toxin they were looking for. in this study)
But it was found only on the casing. Not in the filling!
And removed (to undetectability) by simple washing.
Nevertheless (in the conclusions section) "the presence of OTA on the surface of sausage constitutes a health risk when moulds are not removed from the casings."

So start by washing the mould off. (And its maybe better not to eat the skins!)


Anyone with the appropriate subscription access could probably learn much more by going through some of the other papers cited as references ... The Leistner and Comi papers in particular sound relevant.
Hopefully someone here could do a review for the rest of us?

[Chris Hennes]

Ah, brilliant! There does actually seem to be a very substantial amount of research being conducted in this area, so I guess it's time to start digging into it. I've got access to most of these journals, I think, but it will take a bit of time to assemble a clear picture of what's going on. I agree that the best course of action right now seems to be to simply wash the mold off, and to watch the relative humidity (though I thought that even 79% was quite high for sausage curing... it was nothing like that high in Calabria).

[Chris Hennes]

The money quote from the abstract of the Iacumin article:

From these data it appears that the presence of OTA on the surface of sausage (on the casings) is not indicative of any health risk for human consumption of sausage, since OTA was not identified inside the dry meat.

[dougal]

Thanks Chris - a nice little library research project for the dog-days of August!

...
A few choice quotes from that article (Alvarez-Barrea, et al., "Some Factors Influencing Aflatoxin Production in Fermented Sausages." Journal of Food Science 47(6), pp. 1773 - 1775):

After 6 wk storage at 10°C, no aflatoxins could be detected in any of the samples except for the inoculated-unsmoked sausages held at high relative humidity (89%).

...

This accords with my previous general understanding that 'bad' moulds were favoured by excessive humidity.

... my understanding has been that the hairy moulds are at home in rather higher humidity than is good for the sausage. And hence that they are an indicator that a little more air circulation and a little less humidity could be employed. ...

[dougal]

The money quote from the abstract of the Iacumin article:

From these data it appears that the presence of OTA on the surface of sausage (on the casings) is not indicative of any health risk for human consumption of sausage, since OTA was not identified inside the dry meat.

The Conclusions section puts it just slightly differently ...

Those moulds NEED to be washed off (at least) before eating. They ARE a problem, but the inside of the sausage is fine.

Edited by dougal, 07 August 2009 - 10:08 AM.

[slkinsey]

Getting back to the original question, it seems like Chris Amirault could simply have wiped down the exterior of his sausages (perhaps with a mild vinegar solution?) and they would have been just fine -- especially if he continued to age them and the green mold did not reappear.

[David A. Goldfarb]

Getting back to the original question, it seems like Chris Amirault could simply have wiped down the exterior of his sausages (perhaps with a mild vinegar solution?) and they would have been just fine -- especially if he continued to age them and the green mold did not reappear.

That's what I do, if I see anything suspect, which I usually don't.

[Chris Amirault]

I also saw the counter folks peeling off the casing (that had clearly been washed); perhaps that's an additional precaution?

ETA that I've never cured anything at 30C (which the converter I just used tells me is 86F).

Edited by chrisamirault, 07 August 2009 - 11:38 AM.

[Chris Hennes]

Yes, that definitely seems to be the case, though it's unclear whether it's even necessary (or particularly beneficial) to do so at the first sign of any mold. It seems based on what I've read so far that as long as you wipe it off before eating the salume, you're fine. Some producers seem to wipe it off regularly, while others just let it go and wipe at the end. I saw the guy at the counter peeling the casing off something at Calabria, and when combined with wiping first that is probably the safest way to go.

1. What, exactly, is this "fuzzy green mold"? What distinguishes "fuzzy green mold" from "chalky white mold"?
2. What effects do these molds have? How do you determine which effects are detrimental, beneficial, or both?
3. If, as all the books indicate, this "fuzzy green mold" is so terrible for you, why in the world is a premier salumeria displaying it overhead for all the world to see?

The answer to all of these is about the same, it seems: there are a few hundred species of mold that commonly occur on charcuterie products: of these, a few (most notably Aspergillus ochraceus, Penicillium nordicum, and Penicillium verrucosum) produce toxins under the right conditions. I don't know for sure, but it is possible that none of the problem molds is white, or at least, they are not white when producing the toxin, hence the recommendations seen everywhere to get rid of sausages that have non-white mold. But these toxins seem to remain on the exterior of the salume and can be simply washed off carefully before eating.

[Chris Amirault]

Cure at appropriately cool and relatively dry conditions: check.

Be scrupulous about cleaning during prep, grinding, stuffing: check.

Prior to consumption, wash (with what, exactly?) and perhaps peel casings: check.

If fuzzy, green mold shows up... wash down with a vinegar solution as per Sam's post? rub with olive oil as per the Barcelona dude? let it bloom, bloom, bloom as per the Calabria dudes?

[slkinsey]

I would add to the above, if you want to be scrupulous: inoculate with desired surface mold.

[dougal]

Regarding the humidity, it does seem to be beneficial to avoid allowing it to go excessively high.
However, that applies to conditions very near indeed to the sausage casing -- not just to wherever the chamber sensor happens to be!
Therefore some air movement (just a little) has to be beneficial, to even out the humidity throughout the chamber.
Randomness and change of airflow direction would be needed to prevent establishment of regular flow patterns, which could consolidate humidity differences rather than removing them!
The Marianski's prescribe different airflow speeds at different stages of the sausage cure, but I think that may be more to do with the rate at which the sausages are shedding moisture, rather than direct consideration of the microflora.


If one was being really serious about surface moulds, I suppose one could begin by irradiating the outside of the sausage(s) with UV light, to knock back the inevitable collection of environmental moulds, and only after that, inoculate the surface with a desirable mould culture.
UV would have the advantage of not leaving an anti-fungal residue to impede the desired culture establishing itself.






Regarding the action of 'good' moulds to combat 'bad' ones, one very relevant paper would seem to be
Molds as Protective Cultures for Raw Dry Sausages (published 1994 and 1995)
http://www.ingentaco...000010/art00017
http://www.ingentaco...000007/art00019

Abstract:
Mold strains T11 and T19 belonging to Penicillium camemberti and N1 of Penicillium nalgiovensis were used as protective cultures for production of raw dry sausages. Their use completely eliminated the growth of undesirable molds, originating from the natural house mycoflora, which often produce mycotoxins and lead to several other defects. Potassium sorbate (KS), an antifungal agent, was also tested for protecting sausages against the growth of molds but its effect was short lived. The use of T11, T19 and N1 mold strains also improved the organoleptic qualities of the sausages.

So, could Camembert rind not merely be good, but could it actually be the ideal inoculum for a 'good' sausage casing culture ?

Has anyone got access to the experimental detail in this paper? (For example, did they use the Camemberti and Nagiovensis alone or only together?)





Regarding washing off bad moulds. I can see some advantage in using an acidified wash to discourage some of those 'bad' moulds returning. But some bad ones are fairly acid-tolerant, so its not a magic bullet.
I have no idea what the fungal effect of rubbing down with olive oil might be. It may just add a flavour to conceal any trace of 'mouldiness'!


I recall reading that some moulds can send 'long' filaments 'deep' into their food substrates.
I'm not at all sure how true that might be.
It could easily be the case that any such filaments are merely 'long' in comparison to the microscopic mould fungi, rather than meaning 'longer than half an inch'.

[djyee100]

If fuzzy, green mold shows up... wash down with a vinegar solution as per Sam's post? rub with olive oil as per the Barcelona dude? let it bloom, bloom, bloom as per the Calabria dudes?

I came across this paragraph while reading Pamela Sheldon Johns' Prosciutto Pancetta Salame.

Mold is an important effect of the aging process. As it develops on the surface of the meat, it regulates humidity, allowing the product to dry slowly and uniformly. In the first three or four days, white mold grows only near the lean parts. After two or three months, the skin is uniformly covered in white or gray to green mold. The amino acids and peptides in the meat react with beneficial molds to neutralize any nonbeneficial molds. Controlling the temperature and humidity helps to avoid the production of toxic molds; the ideal conditions are temperatures under 20 degrees C (70 degrees F), with a relative humidity lower than 80 percent.

[Kouign Aman]

Wiping with olive oil would seem to slow or end moisture evaporation from the sausage, so I'd think that only applied to a fully cured sausage if at all.

[kingudaroad]

If fuzzy, green mold shows up... wash down with a vinegar solution as per Sam's post? rub with olive oil as per the Barcelona dude? let it bloom, bloom, bloom as per the Calabria dudes?

I came across this paragraph while reading Pamela Sheldon Johns' Prosciutto Pancetta Salame.

Mold is an important effect of the aging process. As it develops on the surface of the meat, it regulates humidity, allowing the product to dry slowly and uniformly. In the first three or four days, white mold grows only near the lean parts. After two or three months, the skin is uniformly covered in white or gray to green mold. The amino acids and peptides in the meat react with beneficial molds to neutralize any nonbeneficial molds. Controlling the temperature and humidity helps to avoid the production of toxic molds; the ideal conditions are temperatures under 20 degrees C (70 degrees F), with a relative humidity lower than 80 percent.

Like everything else, there seems to be some people who swear that it needs to be one way or you die, and others that claim the exact opposite. Those photos of the green mold on those professionally made salamis are eye opening for sure, and lead me to believe that it is a natural part of the aging process as the above quote states.

I am in the middle of my 3rd try at salami, dry curing in a wine fridge with a humidifier and a humidistat, and have not had mold to speak of during my first 2 batches. But this current project, which has been drying for a week, looks like it is about to bloom hard. I'll see what happens but I now think I'm going to refrain from wiping off any mold until the aging process is complete.

Incubation


after one week