Cured meat, explained

Start with meat; add salt and time

April 5, 2010

During the Easter season, thoughts turn to ham, particularly as a form of a cured meat. What exactly is “cured,” anyway? I’m familiar with salting meats to preserve them, but how exactly does that process work? I don’t know of anyone who’s willing to hang raw meat covered in salt in their kitchen and eat it at a future date, do you? So how do the pros do it and keep it safe? On a related note, what’s the difference between a ham and prosciutto?
— Michael H., Los Angeles, California

I know all kinds of enthusiasts who might be curing their own hams right now, if they weren’t busy fermenting kimchi in the attic or aging homemade Muenster cheese in the basement. Heck, I might even be willing to try it, and I wouldn't be the first.

The two requirements of most traditional cures are salt and time. Salt kills microbes (such as bacteria), which is the purpose of the curing (preservation) process. The cells of animals (and microbes) are covered with membranes that keep big molecules inside, but allow water to come and go. When a high concentration of salt is introduced to the outside of the cell membrane, water molecules leave the cell by osmosis. When enough water leaves a bacterial cell, it dies, or at least becomes inactive, and can’t spoil the meat.

Curing salt.

Civilizations figured this out (the food-not-spoiling part) a long time ago. Most traditional meat preservation is done by “dry curing” — that is, salting the meat and waiting weeks or months for the flavors to develop. The modern industrial alternative is “wet curing” or brining, which is fast but doesn’t develop the same complex, interesting flavors. (The ham most commonly seen on American holiday tables — the same kind shipped around the country as gifts in spiral-cut form — is wet-cured.)

The fun part about dry curing is that not only does it kill nasty microbes, it transforms the meat. The meat loses water, so its flavor is concentrated. Salt gets into the meat’s muscle fibers and denatures (unravels) proteins, changing the appearance and flavor of the meat. Enzymes break the meat’s proteins down further into component parts such as glutamate, which is responsible for savory umami flavors. Desirable, salt-tolerant bacteria contribute additional flavors through slow fermentation.

In the words of food-science writer Harold McGee, dry-cured hams “are to fresh pork what long-aged cheeses are to fresh milk: a distillation, an expression of the transforming powers of salt, enzymes, and time.”

But the news is not all good. While salting does a decent job of inhibiting the major spoilage microbes, under some conditions botulism spores can germinate in salted meat. (In fact, the name “botulism” comes from the Latin word for “sausage” — seriously, look it up.) So while fresh meat comes with a built-in food-safety system (“Wow, this smells like a fraternity grease trap — I probably shouldn’t eat it”), cured meat can harbor some really nasty stuff if it’s not done properly. This problem was solved long ago, too, by adding saltpeter (potassium nitrate) to the cure.

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The modern equivalent to saltpeter is sodium nitrite, which is available in blends with names like curing salt, Instacure #1, or “pink salt.” (It is dyed pink to prevent accidental confusion with regular salt.) A small amount of nitrite very effectively inhibits microbes, including botulism bacteria. It also reacts with the meat to produce the characteristic bright pink color of, for example, corned beef. In addition, nitrite adds its own unique flavor.

However, there is some evidence that nitrite might be bad for you. I certainly don’t put all my faith in the government when it comes to food safety, but for what it’s worth, there are limits on how much nitrite can be in cured meat sold in the U.S., so the implication is that eating tons of it probably isn’t great for you. On the other hand, on the list of things I do that might allegedly give me cancer someday, eating bacon is about as close to “worth it” as it gets.

Nonetheless, concern about nitrite has spawned a new market category of so-called “uncured” bacons, hot dogs, etc., which do not contain added nitrates or nitrites. I’ve given a few of them a try, but I don’t usually enjoy the flavor as much. As Matthew Amster-Burton noted in a recent Unexplained Bacon column (in which he unapologetically explains bacon — WTF?), we’ve grown accustomed to that nitrite flavor in certain cured meats, and some tasters prefer it. But many traditional recipes (such as Italian prosciutto di Parma) achieve a safe cure without adding nitrite. When I cure meat at home (I’ve done bacon in the fridge), I think of nitrite as a cheap insurance policy.

Pancetta: Dry-cured, unsmoked pork belly.

So, how do the pros do it? Through a combination of traditional techniques and bureaucratic red tape. Hams (and other meats) have been safely dry-cured for centuries in cultures throughout Europe, Asia, and more recently, North America. The same basic techniques are still used today (albeit with the help of temperature and humidity control for producers not located in the foothills of Emilia-Romagna).

Now, however, the pros (in the U.S. at least) also have to convince the USDA that they won’t make people sick. The government isn’t really set up to discriminate between an artisanal producer of handmade dry-cured salumi and a factory cranking out 12 tons of Listeria Dogs® per day, so they all play by essentially the same rules. Which means, at a minimum, extremely detailed written procedures and logs (known in the biz as a “HACCP plan” — yum) and a very familiar relationship with their friendly neighborhood USDA inspector. (There is less drama with wet curing, because it usually involves cooking, vacuum sealing, refrigeration, and shorter times from production to consumption.)

As for the difference between ham and prosciutto, there is none, at least not linguistically (“prosciutto” is Italian for “ham”). Of course, those are fighting words to fans of traditional prosciutto di Parma, which is made according to strict rules and quality standards. But the basic curing steps of a dry-cured American country ham are the same as those used to make prosciutto, French jambon de Bayonne, German Schwarzwalder Schincken (true Black Forest ham), Spanish jamón ibérico, Chinese Jinhua ham, etc. (Please note that none of the above are available in a juicy pink Cryovac bag in the refrigerated meat section of your local grocery — those are wet-cured hams.)

Dry-cured, smoked ham from Germany.

The differences in these products are due to many other (often strictly controlled) factors, such as the breed and feed of the pigs, the spices/sugars added to the cure (if any), the aging times, whether the meat is smoked or not, etc.

Cooking and serving choices of finished hams make a huge difference also. American country hams are traditionally simmered for hours and then served in thick slices on biscuits, while prosciutto is usually served uncooked, sliced paper-thin with accompaniments. There’s no reason these two “serving suggestions” couldn’t be swapped (other than the fact that I’d go ballistic if I caught you boiling my $30/pound prosciutto). Thin-sliced uncooked American country ham can be a revelation.

Based in Portland, Oregon, Hank Sawtelle has engineering, legal, and culinary degrees.

There are 11 comments on this item
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1. by Kathy Eckhouse on Apr 7, 2010 at 1:14 PM PDT

Nitrates are important for fermented meat products like salame which are indeed subject to botulinum problems. They are not necessary for whole muscle meats such as prosciutto, pancetta, guanciale, coppa, and lonza. There are other pathogen controls (time in particular).

2. by galew on Apr 7, 2010 at 3:14 PM PDT

Very informative article, but thanks to the Eckhouses in Iowa (La Quercia), I no longer have to make my own. Their American pancetta is terrific.

3. by cmallar on Apr 8, 2010 at 8:12 AM PDT

According to the Cancer Prevention Coalition, there have indeed been studies that link nitrate consumption with cancer - they site three of them, with alarming results like: “Peters et al. studied the relationship between the intake of certain foods and the risk of leukemia in children from birth to age 10 in Los Angeles County between 1980 and 1987. The study found that children eating more than 12 hot dogs per month have nine times the normal risk of developing childhood leukemia. A strong risk for childhood leukemia also existed for those children whose fathers’ intake of hot dogs was 12 or more per month.” The link is here which mentions the other studies:
Perhaps the addition of Acorbic Acid that the USDA requires now is mitigating these affects now, but is the home curer using ascorbic acid too? I’ve been very happy to find companies like Applegate Farms that makes a really delicious no nitrate bacon and a great deli ham. So, even though I really enjoy making things like kombucha, almond milk, and mozzerella at home, I might leave the meats to the pros. Lord knows we have enough access in Portland to artisanal meats to satisfy my pig hankering any time - Olympic Provisions, Laurelhurst, etc and so many great restaurants like Nedd Ludd doing it themselves - there’s so much great pork to be had here!

4. by Katherine Eckhouse on Apr 9, 2010 at 8:56 AM PDT

A lot of processors use celery extract or juice, naturally high in nitrates, instead of synthetic nitrates both for safety (botulism) and fixing the color (that rosy hue. A lot of labels will say “No nitrates or nitrites added” and then “Except what is naturally occuring in celery.” It’s still nitrates and nitrites, but the source is different.

5. by Jessica Rodgers on Apr 16, 2010 at 9:10 PM PDT

your writing has a subtle laugh-out-loud funniness to it. I loved the comment about Unexplained Bacon...being explained :) Also your background in so many fields adds a new depth of perception to food.

6. by Marcia on Jun 18, 2011 at 3:50 PM PDT

I think that naturally cured or “no nitrates or nitrites added except what is naturally occuring in celery” must be better for you than insta-cure solely based on the fact that celery has alot of other nutrients that probably counteract the nitrates it contains. Otherwise people who eat alot of celery would be dying of cancer. My butcher uses beet powder for natural curing. It is like celery juice but gives the meat a nice pink color. Please tell me if you think I am wrong about this. I need to know. Thanks in advance.

7. by Katherine Eckhouse on Jun 20, 2011 at 2:35 PM PDT

I don’t know if the body metabolizes materials from synthetic and “natural” sources differently. It’s not so much that nitrates/nitrites are inherently bad as it is that when subjected to heat (esp. high heat) they convert to nitrosamines which are bad! Michael Ruhlman has a really interesting “rant” on his blog about natural and synthetic nitrates. We don’t use them because we don’t need to for the kind of whole muscle cured meats we make.

8. by anonymous on Feb 26, 2012 at 4:41 PM PST

a nitrite is a nitrite, clear cut and no beating around the bush. Spinach can contain 2500mg of nitrites where cured meats contain 10-20mg on average. It becomes bad when you eat extra crispy bacon or when it burns.

9. by anonymous on Sep 9, 2012 at 11:56 AM PDT

Nitrates are very dangerous for people like me! Thanks to Nitrates I Have had so many respiratory arrest events. I can not consume anything that contains nitrates. So everything fresh and with out food preservatives, No nitrates food can be preserved any other way. Nitrates are the cheap way to go.

10. by Rick Peck on Aug 17, 2013 at 9:18 AM PDT

Excellent info, clarifies to me that osmosis of water from bacteria cells lurking in the food item is a major reason why salt cures preserve food. Unlike other visitors to this site, my major interest is cool lessons for my middle school science students. Am sure there’s something we can do, although the devil is in the details, as teachers who introduce botulinum to classes are not favored. Some neat tie INS to history too.

11. by Rick Bevins on Sep 6, 2013 at 11:00 AM PDT

Great post. This stuff is really informative. I am trying to do some meat curing at home and am wondering about my fridge. I bought a used fridge to cure in and I am wondering if the possibility of the presense of other “food spores” might effect the outcome? Obviously I have cleaned the fridge very well but I guess maybe its better to be safe than sorry? Should I buy a new curing chamber? You can see what it is here on my site... ... please let me know what you think. Thanks again for the article!

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Hank Sawtelle has engineering, legal, and culinary degrees, and an intense curiosity about food and cooking. Follow Hank’s blog, Sous Vide Jones.

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