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Curing meats is one of those things that began as a necessity, but has hung around because it is just so damn delicious.

Cured meats are everything we like about meat dialed up to 11. They’re saltier, fattier, and more flavorful than their uncured counterparts.

Originally, curing was invented as a way to prevent spoilage and make meat inhospitable to microbes. It goes way back, before Christ, even. Even Cato the Elder had a favored curing method:

You should salt hams in the following manner, in a jar or large pot: When you have bought the hams cut off the hocks. Allow a half-modius of ground Roman salt to each ham. Spread salt on the bottom of the jar or pot; then lay a ham, with the skin facing downwards, and cover the whole with salt. Place another ham over it and cover in the same way, taking care that meat does not touch meat. Continue in the same way until all are covered. When you have arranged them all, spread salt above so that the meat shall not show, and level the whole. When they have remained five days in the salt remove them all with their own salt. Place at the bottom those which had been on top before, covering and arranging them as before. Twelve days later take them out finally, brush off all the salt, and hang them for two days in a draught. On the third day clean them thoroughly with a sponge and rub with oil. Hang them in smoke for two days, and the third day take them down, rub with a mixture of oil and vinegar, and hang in the meat-house. No moths or worms will touch them.

It’s a fairly straight-forward recipe, and all it requires is several hams and endless amounts of salt.

The salt is key.

Usually, when you think of salt, you think of table or sea salt: sodium chloride. But chemically speaking, the word “salt” has a much broader meaning. A salt is simply ions of opposite charge bound together. In table salt, sodium is positively charged (this is called the “cation”) and chloride is negatively charged (the “anion”). These charges keep the two ions together rendering the salt neutral as a whole.

A salt can be composed of just two atoms (such as sodium and chloride), or it can be composed of many (referred to as “polyatomic”). In sodium acetate–the substance that give salt and vinegar chips their famous tang–the cation is still sodium, but the anion is acetate–a polyatomic anion composed of two carbon atoms, two oxygen atoms, and three hydrogen atoms.

Several salts are important to the curing process, but sodium chloride is the star, so we’ll start with it.

The enemies of preservation are bacteria and mold. Both of these little beasties need water to thrive, and salt deprives them of that through a process called osmosis. If you recall from this post a few months ago, osmosis is the movement of a solvent across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration in an attempt to equalize the concentration on both sides. Solutes are things that get dissolved, and solvents are what do the dissolving.

By introducing a large amount of salt into meat, we surround the microbes with a huge concentration of sodium and chloride ions. In an effort to equalize the concentration on both sides of the cellular wall, water flows out of the microbes and salt flows in. Not only are the cells dehydrated, but their machinery is disrupted, resulting in their demise (or at least slowing their growth drastically).

But weep not for them; they could have been botulism. In fact, botulism was originally referred to as Wurstvergiftung (sausage disease) by German scientists due to the fact that Clostridium botulinum had been found in insufficiently or unevenly salted sausages (McGee, 1984).

In addition to murdering microbes, salt also affects the meat proteins in delightful ways. Dehydration concentrates the flavors, while the chemical nature of salt changes the texture. Proteins are long chains of molecules, held together by electrostatic interactions. The ionic nature of salt disrupts these bonds, denaturing and weakening the muscle fibers. If you’ve ever had prosciutto, you’re familiar with salt’s ability to turn a hunk of raw meat into something silky and flavorful.

Prosciutto is one of those meats that seem to be greater than the sum of its parts. When you let one of those delicate, raw slices dissolve on your tongue, you don’t just taste pork and salt. Not only is the meat meatier, but also somehow fruitier. This is all because of enzymes; they work tirelessly during the curing process, converting bland proteins into flavor compounds and spiking the amount of glutamic acid (responsible for that wonderful umami sensation) ten or twenty times over (McGee, 1984).

While there are some meats that are cured purely with sodium chloride (prosciutto being one), there are many that require additional salts to prevent spoilage. Sodium nitrate (originally called “saltpeter”) was added in the 16th and 17th centuries to cured meat as a way to improve meat color, safety, and shelf life, but around 1900, a bunch of German scientist determined that some of the nitrate was being converted to nitrite, and that was what was doing the trick.

Once that was all sorted, small amount of pure nitrite were added to meat, having three main effects:

1. Contributing its own sharp and tangy flavor

2. Reacting with the oxygen in the meat to form nitrous oxide, a molecule that binds to iron and prevents it from oxidizing.

3. Slaying bacteria by interfering with bacterial enzymes and energy production.

There is some concern about nitrites reacting with other compounds in food to form carcinogens, but if it’s between cancer and botulism, I’ll take a small amount of nitrite (less than 200 parts per million) with my bacon (McGee, 1984).

***

You know what’s more fun that talking about salty meat? Eating salty meat.

Let’s talk charcuterie.

In my mind, a perfect charcuterie board should contain three to five options, with at least two being of the salty, cure variety. For a board with five choices, I would include:

1. Prosciutto di Parma. Raw and as thin as you can get it. Wrap around breadsticks for easy eating, or fold in little piles so your guest can easily grab them by their edges. If you want to be super classy, serve with cubed melon.

2. Salami of some sort. Opt for something with visible circles of beautiful fat; do not mess with anything that says “reduced” anything on the package. [Editor's Note: Try 'Nduja!!!]

3. A cooked option, like Mortadella the bologna-style sausage that is the classy cousin to its American cousin (it’s those fat cubes).

4. Something Spicy: You could go the cured route with sopressata or opt for another cooked meat and pick up some capicola. Both are good options.

5. Finally, I would round it out with something spreadable. A good pâté or terrine are easy to make and impressive to serve. They may not be for everyone, but your guests who appreciate them will really appreciate them. [Editor's Note: Have I mentioned 'Nduja?]

The extras: I’m perfectly happy to eat sliced meat for hours on end, but it’s nice to provide some accessories. Mild creamy cheeses help balance out the salt, while sour pickles help cut through all that fat. Add a few olives and some crackers or baguette slices, maybe honeycomb or homemade fruit preserves or chutney if you’re feeling fancy, and it’s a party.

Harold McGee. 1984. On Food and Cooking: The Science and Lore of the Kitchen. (New York: Scribner), 172-174.

Savor the Science: Cured Meats