Meat curing safety

February 24, 2011

Some of you might know that I am one of the judges for the rather large, rather viral #charcutpalooza challenge. I am in great company there I have to say, and the challenges are shaping up to be very interesting. Michael Ruhlman does a great job in his Charcuterie book to go in to some detail about the safety side of things when curing meat, but I figured I would add my thoughts on the whole safety side of things too.

When I started meat curing at home many years ago I promised my wife two things – If I thought it might dicey, I wouldn’t eat it. I would read up as much as possible on the safety of curing meats, the process and so on, so that I can guarantee my work is safe.

If done properly, with good technique, attention to detail, and the right environment curing meat is safe. Very safe. It has been done for centuries. People in the past have died from it so we don’t have to. Sounds harsh, but it is true. No need to make the mistakes that others less fortunate have. With that in mind, here is a list of safety facts that I have gathered along the way, to make sure what I do doesn’t make myself, or even worse other people sick.

1) If in doubt, throw it out. Goes without saying, however it is an incredibly hard thing to do. I have thrown out quite a bit of product. Most likely perfectly safe, very tasty product – however I will never know. Some pieces developed some nasty black mold. That is an instant trash-can job for me. Others got some case hardening that I wasn’t fond of. It is all a learning experience. If it went right all the time we would never learn as much.

The biggest thing here is your time and emotional investment. Throwing out a piece of meat after it has been hanging for two months is a tough thing to do. However, if you have any doubt as to the safety of it, it goes. Use your instincts. Does it smell OK? Does it look OK? How well is it drying? What is that growing on the outside of it? Has my temps and humidity been good?

Generally things are most critical around the start of the drying process, when the meat is most damp. As the product dries out, less potentially can go south, apart from case hardening (more on that later). Due care and attention is really all that is needed. If something looks wrong, find out what it is and how to fix it. Email me if you want, and I can see if I can offer suggestions.

One last thing I should add. If you really are rather attached to that piece of charcuterie you have hanging and hate the idea of throwing out what might be a perfectly good piece of salty dried meat – go get it tested at lab. Sounds ridiculous  I know, but there are labs all over the country that for a small fee will test your meat for nasties. It might end up costing more than the meat you bought to do the charcuterie in the first place, but at least you know. A friend told me of one place in Seattle that will test meat for pathogens for $35.

A friend recently had to throw out a whole prosciutto after it had been curing for 6 months, because a fly got in to the meat. It is heart breaking, truly heartbreaking but you gotta do it.

2) Use properly raised meat

This isn’t just my personal ideology, but something I consider important to the safety of the meat. Use meat from small non-intensive farms that have care for the animals they are raising, and that have the meat slaughtered and butchered properly. Studies have shown these meats have less bacteria in them.

3) Temperature and Humidity (for dry curing)

When air drying (dry curing) meat you want to keep the environment within a certain temperature and humidity range. The temperature range should be high enough for the meat to cure properly and dry, but low enough so bad bacteria and mold doesn’t grow. Ideal temperatures are between 50-60F (10C-15C).

Humidity is equally as important as temperature. The humidity of your hanging environment needs to be between 65% and 80%. If the humidity is 80% or above you better have some air movement in your environment otherwise nasty stuff is going to grow. For points of reference – a house heated by a furnace in the winter is going to be about 40% humidity in cold climates. Your regular fridge at 36F is going to run between 30 and 50% humidity, depending on what is in it.

Before you start any air drying of meat you need to accurately measure your environments humidity and temperature. To do this you can use a temp/humidity sensor. I personally like this one. It is small, cheap and you can calibrate the humidity sensor on it, which is pretty important because all humidity sensors can be inaccurate.

4) Dry curing (air drying) environment

It should go without saying that you want to keep the meat away from pests, bugs, rodents… and pets. Don’t hang anything in a place where your pets can give it the stink eye. My personal preference is to keep the stuff away from anything toxic too. I have my curing chamber in my basement garage, however I have moved all those paint cans and so on that seem to collect over the years out to the shed. Going a bit far? perhaps.. but well, that is just me.

Before you go and spend any money converting a fridge or whatever to an environment to dry cure meat in, go buy that temp/humidity sensor listed in 3. Over the course of a couple of weeks position the thing in various (SAFE) places around your house for 24hours, and see if areas in your house have the right temp and humidity range to cure meats in. Often a good choice is a cool slightly humid basement. Remember of course that over the course of seasons your environment is going to change, so keep an eye on the measurements.

If you do want to go down the “building a meat curing chamber” route, then may I suggest taking a look at this post I wrote a while back on converting an old fridge to a meat curing chamber: The whole project can be done for just over $100, if you find a fridge on craigslist for free (there are often a lot of old fridges going for free if you can just pick em up).

5) Nitrates and Nitrites

I wrote a long post about these often misunderstood curing ingredients here. In short – USE THEM. I don’t want to hear that meat has been cured for centuries without them. People died from botulism poisoning, you don’t have to. That Spinach salad you ate with your dinner last night? Yep. That had more nitrates in it than a whole salami.

Recent studies have also shown that nitrates are beneficial in cardiovascular health, when consumed within safe limits.

I recommend against using celery powder. The amount of nitrate in it is totally variable, so you could end up consuming far more than the accurately measured professional cure.

It is almost impossible to buy straight nitrate or nitrite. I also totally recommend against doing so. The actual amounts of each you need are very small, and if you over measure you could make yourself very sick. Instead, go to SausageMaker and purchase Cure 1 and Cure 2.

Cure 1 is salt and nitrite, and is used in bacon and other smoked meats. Cure 2 has salt, nitrite and nitrate is used for long aged dry cured meats and salami. Make sure you keep both of them away from children and pets, and stored away from other cooking ingredients that they could get mixed up with. I personally choose to keep all my meat curing ingredients and small equipment inside a plastic storage box on a high shelf in the garage.

6) Botulism

Botulism is a rare but incredibly serious food borne disease. Fatal. C. Botulinium is found in soil and sediment all over the world. The bacteria itself can form a spore which is incredibly resilient to heat and chemicals. These spores are not dangerous unless they are in the right environment for growth. The spores can then germinate and the deadly toxin Botulism is produced.

The bacteria grows best in anaerobic conditions (without oxygen). In this condition, at the right temperature (78-95F is optimal, but growth can happen between 40F-120F) then spores that are formed will produce toxins.

In order to grow these bacteria need a slightly acidic, damp warm environment. The interior of a sausage is pretty much exactly that.

The botulism bacteria can be found on the outside of meat. This isn’t generally a problem if you are hanging whole muscles – since the outside is open to the air, it isn’t an anaerobic condition. Even if you case your whole muscle cuts it still isn’t oxygen free, since the casing allows the passage of air and moisture. If however we take a whole muscle and grind it up – now we have a problem. The exterior has now become the interior. When this gets tightly stuffed in to a sausage casing, you have a warm, moist (meat has a lot of water in it) oxygen free environment.

The same thing goes for smoking any kind of meat. The smoke environment, if very thick, can be considered oxygen free. So then even a whole muscle cut could be a possible breading ground for botulism.

It should also be noted that when making a rolled pancetta you are technically rolling the outside of the meat in to the inside, and creating an air free environment on the inside of the roll. I guess you now know my thoughts on nitrates in pancetta..

The use of nitrates/nitrites is the only thing known to stop the transformation of the spores to toxins. That is why nitrates and nitrites are so incredibly important.

The risk of getting Botulism is incredibly small. However it’s severity cannot be underestimated.

7) Mold

I get quite a handful of emails a week from people asking me to look at pictures of their drying meat, and to give my opinion on whether a certain mold is safe or not. I am certainly no mold expert, so you can imagine my reply – but here is the basics about mold on dry cured meats:

WHITE: powdery white mold is good. A form of penicillin. It will have a smell of ammonia. White mold that is furry or hairy is bad.

GREEN/BLUE: not the best. If this is present you generally have a humidity or airflow problem. Try to either lower the humidity in your hanging environment, or make sure there is some positive airflow in your chamber, with regular transfers of air (get the stale air out, and fresh air in).

BLACK: Serious stuff. Can be toxic. Generally only forms when there is very high humidity and no air movement. I have only ever had black mold appear once. For me anything that grows black mold is instantly thrown away.

The best way to deal with a case of the fuzzies or blue/green mold is simply to wipe the area in question with vinegar. It wouldn’t hurt to wipe your chamber with the stuff either. Once you are done curing, clean the chamber out with a 10% bleach solution and let it dry for a couple of days before using again.

The air around us has all manner of mold spores in. If we hang meat in any kind of environment it is going to most likely get both good (powdery white) and bad (blue/green) mold on it – especially if your humidity isn’t perfect. The best way to help the good mold along is to actually spray the hanging meat with a mold culture. This will cover the meat in lots of good mold that over the course of a week will grow rather nicely, and soon cover the meat – helping prevent anything nasty from growing. The product is called Bactoferm 600 and can be bought here. Mix 1 teaspoon with 1/4 cup of distilled water (the chlorine in tap water will most likely kill the good mold), and leave at room temp overnight. Dilute further with another 1/4cup of distilled water, and mix. Let this sit for 30 minutes, then spray or pour over your hanging meat.

You will find that once you have a good curing environment setup then you most likely wont have to use the mold spray that often. The atmosphere of the chamber (and the neighboring salami) will have good mold on them which will inoculate the newly hung pieces.

Can you eat the white mold? YES you can. Personally I am not that keen on the taste of it, but you can certainly eat it. When eating salami I peel the casing back, and slice the meat, discarding the casing as needed. That is really just personal preference though. Remember that some casings are considered inedible.

8.) My meat has been hanging for ages… when can I eat it?
Before you hang the thing to dry, weigh it. When it has lost 35% of it’s initial weight, it can be considered safe to consume. Personally I like to let a lot of my products go to 40-45% – I prefer the texture.
The only exception here really is if you suspect case hardening. Case hardening is a situation where the outside of the meat has dried out so much that moisture on the inside is unable to escape, since the dry exterior has formed a thick crust. This can mean that whilst the exterior has obviously lost enough moisture to be considered safe, the interior certainly has not. Case hardening is caused by too low humidity, or too high airflow – or both.
If you suspect case hardening (give the meat a squeeze.. if it still feels squishy on the inside, but really hard on the outside then you have case hardening) the best thing to do is to vacuum pac the meat and put it in your regular fridge for a few days. This will help even out the moisture level across your meat. If you don’t have a vac-pack machine (shame on you) then put it in a ziploc bag, and try your best to get all of the air out of it.
9) Don’t worry have fun.
So what if it all goes a bit wrong. Meat curing is fun. You will end up throwing something out. Everyone does, even the professional producers. Just enjoy it, and don’t stress over your meat..


How to convert a fridge to a curing chamber

How to make salami at home

All about nitrates and nitrites


Charcuterie – Michael Ruhlman

Art of making Fermented Sausages – Marianski

Cooking by Hand – Paul Bertolli

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  • Brian Silvey February 24, 2011 at 4:12 am

    As a newb to curing meats I can’t get enough of these types of articles. It may be some info I’ve seen before, but hearing it again reinforces the concepts. Curing safely is as much art as it is science and experience is the only way to feel confident in what you produce.


  • Julia February 24, 2011 at 1:15 pm

    Thank you so much for such a thoughtfully written piece. The time you have spent on this and the rest of your work makes it much easier for folks new to this to navigate. Your time and energy are appreciated!!

  • ruhlman February 24, 2011 at 1:56 pm

    Excellent post, great information. I wrote a post on the same subject here:

    I would add to your “when in doubt, throw it out” motto. You can also cook it. Most molds and toxins that might develop in charcuterie projects will be killed or nullified by high temps.

    Thanks for the good words on nitrites and nitrates, all accurate. It should be noted that they can only exist when carried on something else, such as sodium of potassium. Sodium nitrite should be handled with caution. A report on an Oxford U. health page says that it’s lethal at 71 mg/kg. That would be 2 teaspoons for me. And less than that could still be harmful. Don’t be afraid of it, just don’t put it in your salt shakers. Household bleach could hurt you too and we’re not afraid of that.

    Also, some studies suggest that nitrite converts to nitric oxide so quickly that by the time you eat it, there’s very little in your food.

    Mold is good on a couple of counts and I always use the mold product you mention (I also get curing salts and everything else there, prices much better). Not only does it ensure that bad bacteria don’t grow in the same spot, it also keeps out light (which can make fat rancid) and it devours the oxygen at the surface of the meat to help prevent oxidation.

    Most important thing you said in the post? “Have fun.” Yes!

    • mattwright February 24, 2011 at 5:51 pm

      Thanks for the comment Michael. I might add that whilst sodium nitrite should indeed be handled with much caution, because the only public access to the stuff is really via cure1 and cure2, the risk of an overdose of the stuff is much less likely, since cure1 is only 6.25% nitrite.

      I love the fact that I really don’t have to spray with mold solution anymore. Within a day anything new I hang in my chamber is starting to get a good covering of powdery white mold, and after 5 days it has a good coverage! Great for me, since I always forget to mix up bactoferm 600 before starting a curing project..

      One thing I have noticed is that the formulation of B-600 has changed, from what it was MEK solution. It seems to start off much thicker, and then after a couple of weeks receed back to the powdery stuff. At the start it seems almost pillowy in nature. Apparently they added a chump of dextrose in to the B-600 mix which wasn’t in the MEK – this helps the bloom start very rapidly. (this is what I heard anyhow)

  • fritzg February 24, 2011 at 3:05 pm

    Very thorough post. I keep wondering though, how these environments were controlled (temp and humidity) before refrigeration. With hams hanging for months and up to a year, I imagine the temp and humidity range is more fluid than the one named here as the ideal.

    • mattwright February 24, 2011 at 5:45 pm

      fritzg – Curing was traditionally done through the winter. By the time spring came the meat had lost enough water content to be safe at higher temps. Curing was also done traditionally in cooler areas – people would use underground rooms, huts up in the mountain and so on.

  • Ray Miltier February 24, 2011 at 3:45 pm

    Your post a pure inspiration! Keep up the good work.

  • Brian Silvey February 26, 2011 at 10:41 pm

    Just took my pancetta out and gave it a thorough going over. I did find a bit of mold on the rolled ends, but nowhere else. A tiny dot of white and a whitish green bit on the other end. The greenish white mold was growing in a crevice of the rolls. Smells fine. I cut the ends off (yes I tossed those) and then cut it down the middle to examine the inner roll. Inside looks tightly rolled with no signs of any color that shouldn’t be there.

    Tonight I’m going to make a clams and linguine with pancetta.


  • philippe Duvillard February 28, 2011 at 2:14 pm

    Why have you not attempted whole cured ham yet, is it just the size? afterall the temperatue for maturation is almost the same just the humidity is lower.
    I live in India where i have started making charcuterie and cured bits of meat and i think i am about to embark on a crazy venture of turning it into a business; of course most of the product i haven t made yet but ‘research’ is my middlename and i have no fear in the kitchen ( and many culinary areas) . Any way i was just wondering about the cured ham, in the mean time i applaud your knowledge and beautiful site. Will give news of my struggles, meat rules!

    • mattwright March 1, 2011 at 5:06 am

      Philippe – there are a few reasons. The size especially – not during drying, I have room for that, but more in my home fridge for the salting and curing. The cost is prohibitive right now for me too. I only used properly raised local hogs, and a whole leg will set me back $120 or so.

  • zenchef March 3, 2011 at 4:37 am

    This is a masterpiece, Matt. You have quite become the expert in meat curing. Fascinating stuff. When are you writing the book?

  • Rand March 5, 2011 at 3:10 pm

    I have a question about a ham that I have hanging. I had it packed in salt for three weeks. I then rub it all over with a pig lard and wrapped it in cheesecloth. I think I am noticing some black spots on it after a week or so of hanging. Should I be concerned and can I save the ham if it is going bad? Thanks

    • mattwright March 7, 2011 at 4:48 am

      Rand – I don’t have experience doing a full ham, right now I don’t have the space to do one. Send me a picture though, and I will take a look.

  • Sebastien March 7, 2011 at 5:31 pm


    Do you use Bactoferm 600 on encased meats only? I am making breasaola and lomo and was wondering if I should spray them, just to be sure

    • mattwright March 7, 2011 at 5:50 pm

      Sebastien – You can use it for anything. It is in fact a really good idea to use it for whole muscles that you haven’t put in a casing, since it helps slow down water loss from the meat, and helps prevent hardening of the outer layer of the meat.

      I might suggest trying casing a lonzino and bresaola sometime. Your best bet is to buy a “beef bung” casing – these are about 3.5″ to 4″ wide, which is generally pretty suitable for lonzino and especially bresaola.

  • Rand March 7, 2011 at 6:20 pm

    Thanks for replying matt. Would anyone else on this blog beable to answer my question?

  • Brian Silvey March 12, 2011 at 5:03 pm

    Interesting post by a fellow on chowhound, check out pigwizard towards the end, . Very interesting comment about Egyptians, mummies and a local salt that seemed to do a better job of preserving.


  • Sam Hiersteiner March 13, 2011 at 2:39 pm

    All – Thanks in part to Matt’s inspiration, I did an interview series with the chefs who are competing in this year’s Cochon 555, the heritage breed pig cookoff, in Washington, DC (

    I’ll also be live tweeting @samsgoodmeats starting today (3/13) at 330pm. Follow me if you’re interested!

  • j biesinger March 14, 2011 at 6:44 pm

    I was wondering about your statement that meat that has lost 35% of its initial mass is safe to consume. While I’ll agree that texture is preferable past this point, I can’t find any information to corroborate the 35% cutoff.

    I’ve been researching the concept of water activity, and, unless my math is wrong, even a 35% reduction in water content won’t get water activity below 90% (AW <85% is considered safe without refrigeration).

    Maybe this isn’t about water activity? What am I missing?

  • T.O'Neill March 15, 2011 at 1:48 am

    What a great blog.

    I just finished my first pancettas, and am a bit worried about the interior of one that I cut today. I used pink salt, cured, then dried the pancetta for a week in the fridge. The recipe claims that it doesn’t need to finish drying, but when I cut into it, the end part looked a bit gross (darker than surroundings, and most as compared to the outside).

    Is it okay to cut off the unappealing part then cook the rest?



  • T.O'Neill March 15, 2011 at 1:54 am

    I just cut into one of two pancettas that I made (my first attempt). I noticed that at the end, there is a bit of unappealing, dark, slightly soft meat in the center. It has not dried as long as recommended, but the book (Ruhlman) said this was fine. Should I cut that part off and cook the rest to a high temp? The meat was cured with pink salt prior to rolling.

    I think part of the issue is that I am a bit freaked out to eat home cured food.


    T. O.

    • mattwright March 15, 2011 at 2:53 am

      Tim – I obviously cannot comment as to whether you should eat something you cured or not. However – here are my suggestions –

      1) does it smell bad? if so, in the trash it goes.
      2) what temperature did you hang the meat at?
      3) how long has it hung for?

      since Pancetta is cooked, generally it is a lot more forgiving than other cuts. Feel free to send me a picture if you want me to take a further look. You can find my email on the about page.

  • T.O'Neill March 15, 2011 at 3:40 pm


    I hung the meat in a fridge at 37 degrees F. I read Ruhlman’s site, and combined with the suggestions here, ate the meat cooked with greens. It was great, and I am fine,


  • gerry March 19, 2011 at 5:33 pm

    Matt – I, too, have been bitten by the curing bug. First it started with bacon, the gateway drug of charcuterie… Now I am on to guanciale, which has been curing in my basement shop for two and a half weeks. The temp was great at a steady 50 degrees, but humidity was low (about 25-30%) here in Utah. A tall garbage can with salt tray at the bottom did the trick. With a lid slightly askew, humidity in the “curing chamber” has been maintained at a steady 65-70%. One thing I am considering to add is a small fan on a timer to get circulation going.

    Thanks for your inspiration and for sharing your experiences!


    • mattwright March 19, 2011 at 11:05 pm

      Gerry – let me know how you garbage can curing chamber works out! Certainly the first time I have heard of it – I love how inventive people are at making the right environment for this.

      Just one thing – make sure you aren’t doing anything in your shop that could get on to the meat.. sawdust, paint fumes and so on.

  • Isaac Rivera April 29, 2011 at 8:55 am

    Great post Matt. Though I ferment many things at home, I have not taken up meat curing yet. But it is something I have a lot of interest on. Currently I am residing in Barcelona, Spain. I have scouted a few local, high quality fuet and ham producers and quite enjoy these artisanal products. Your article has brought some light to the nitrates/nitrites issue for me. However, I still have a lingering question that I have found little information on. Trichinella. I have found research conducted in canada that proves there is no surviving Trichinella larvae in ham after 39 days of curing. Good quality Spanish ham is cured for 24 months, so that seems to be safe, but I believe fuet ( is cured for 3 to 4 weeks only. Do you know anything about the safety of Trichinella infection with cured pork?

    • mattwright April 30, 2011 at 3:12 am

      Isaac – I cannot speak for Spain, however I know that here in the USA there hasn’t been a case of trichinella in domestic pork for a long time (at least 15 years I believe). If you are dealing with wild boar then that might be a different case. I have heard that one way to kill trichinella is to freeze the pork for at least two weeks. I have never done this however.