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.
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.
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.
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.)
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. Email questions for the Ask Hank column to AskHank@culinate.com.
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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