Salt Talk

Making tasty use of nature’s prime preservative

by Peter Barrett and photographs by Jennifer May, December 29, 2008

Salt is the only rock that we eat. It’s essential for our survival, was used as currency, and is now available in a dizzying variety of textures and varieties from all corners of the world. It is also the key to transforming humble meat and vegetables into sublime delicacies that can completely change our relationship with everyday ingredients, giving us more control over our diets and allowing us to add an artisanal flourish to our cooking. As Mark Kurlansky notes in Salt: A World History (Penguin, 2003), “Salt is so common, so easy to obtain, and so inexpensive that we have forgotten that from the beginning of civilization until about 100 years ago, salt was one of the most sought-after commodities in human history. Salt preserves. Until modern times it provided the principal way to preserve food.” The careful combination of salt and time results in staples which kept our ancestors alive through many thousands of winters, and happen to also be profoundly tasty—they add extra bass and treble, as it were, to our home systems. And making these wonderful foods in your own kitchen couldn’t be easier (or cheaper).

Picture a fast-food breakfast muffin: a warm, damp, greasy little stack of culinary defeat. All the ingredients are industrially produced, and it’s laden with fat and cholesterol. It’s not good for us, or for the planet. But it’s convenient, and ostensibly inexpensive. Now picture a similar arrangement, but with crisp slices of home-cured pork, a local egg, and your own crunchy kimchi on good toast: a toe-curlingly satisfying (and guilt-free) experience. With little more than a bag of salt and a few minutes on a weekend, you can make this your new standard for breakfast and never look back.

Salt preserves food in two main ways: dehydration and fermentation. Dehydration, or curing, is usually used for meat and fish. A filet of fresh wild salmon, covered in salt, brown sugar, and some flavoring (fennel seeds, citrus zest, a little hot pepper) for a couple of days, becomes lox. Fermentation takes place in a brine, where benevolent microbes create acid and thus create pickles. Shredded cabbage and salt, packed together in a ceramic crock and left somewhere cool, will produce tangy, funky, authentic sauerkraut in a week or two.
Our bodies need salt to live; without it we cannot regulate the flow of water between our cells, tissues, and organs. Different levels of salinity in our bodies cause water and salt to migrate back and forth across our cells’ semipermeable membranes in order to reach a balance. This process, known as osmosis, is the key to how salt has been used for countless millennia to preserve meat and fish. If a cell—either of muscle tissue or an undesirable bacterium—is exposed to enough salt, the osmotic pressure from the salt will pull the water from the cell, drying it out. This kills the bacterium and makes the meat an inhospitable environment for future microbial growth.

Sugar is often included in a cure, as a balance against excessive saltiness, and because it creates even more osmotic pressure than salt. If the cure in question has also been mixed with herbs and garlic, then those flavors will migrate into the meat along with the salt. After about a week packed in salt, sugar, garlic, and herbs, a pig jowl or belly will weigh significantly less than its starting weight; the formerly dry cure will now be a liquid brine from all the water the meat has given off. The denser, salty, richly flavored meat is then ready to be air-dried or smoked.