In the days before refrigeration, preserving perishable foods, such as fresh meat, was an important survival skill. Salt and other naturally occurring chemicals, such as saltpeter, could make meats edible for months after slaughtering, providing an important source of protein. In more recent centuries, sugar has become a curing ingredient as well. Fresh meats are now available year-round at moderate cost, but cured meats remain a delicacy because of their rich flavors.
How Curing Works
People have known how to cure meats with salt and other ingredients for thousands of years, but scientists have only recently come to understand how the process works. When there’s a high concentration of salt at the surface of a piece of meat, the salt draws moisture from the meat’s cells through a force called osmotic pressure. After the salt draws out a great deal of the moisture from the meat, the pressure changes, and the cells draw part of it back. Any bacteria, yeasts or parasites in the meat are subjected to the same force, and that excess of salt kills them just as surely as it would a human.
Sugar and Sweeteners
Sugar and other sweeteners play two roles in the curing process. Like salt, they draw moisture from the meat through osmotic pressure, though sugar isn’t as powerful a curing agent. Sugar’s importance in the curing process is more a matter of flavor. Pure salt gives a relatively harsh flavor to cured meats, but sugar and other sweeteners, like honey, provide a mellower, more rounded taste. Varying the ratio of salt and sugar provides a sweeter or more savory flavor.
Each sweetener has its own flavor characteristics. Ordinary granulated sugar is sweet, but neutral. Honey and maple syrup have distinctive flavors that work well with hams and bacon, while the sharper taste of molasses works well with some highly spiced deli meats. Many recipes call for brown sugar because it’s a pleasant compromise between flavor and neutrality. It’s less distinct — and more versatile — than honey, molasses or maple syrup, and it adds more flavor than plain white sugar.
Mixing Your Cure
Your curing mixture can either be a dry rub, or a flavored brine. Most recipes call for half as much brown sugar as salt, but you if you like a sweeter cure you can go as high as equal parts sugar and salt. If you’re preparing items, such as hams, that might be stored for a long time, ask your butcher to sell you some tinted curing mixture or Prague powder. They’re curing mixtures containing nitrites or nitrates, which keep your cured meats safe for longer. You can develop more complex flavors by simmering the salt and sugar with herbs and spices to make a brine, then soaking your meats in the liquid after it cools.
It’s important to remember that meats can spoil and become dangerous without necessarily developing unpleasant flavors or odors. If you’re new to curing your own meats, follow recipes from reputable sources, such as the Culinary Institute of America or the National Center for Home Food Preservation. Follow the directions scrupulously, or your meats might spoil. It’s best to start with small pieces, such as fish fillets or slab bacon, which cure quickly, rather than a whole ham, which requires special equipment and extended curing time.
References and ResourcesOn Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
Garde Manger: The Art and Craft of the Cold Kitchen; Culinary Institute of America
Charcuterie: The Craft of Salting, Smoking, and Curing; Michael Ruhlman, Brian Polcyn