Salt, Sugar, Acid, and Dryness:
When foods are very salty or sugary, they draw water out of bacteria, which either kills the bacteria or keeps their numbers down. Thus sugar and salt keep in the pantry indefinitely. Many sweet or salty foods will also keep for long periods. Many types of candy, stored in a tightly closed container, last for a long time on the shelf. Honey and pancake syrups keep without refrigeration for about a year; molasses will last for six months. Genuine maple syrup, however, tends to mold and eventually ferment in the pantry (after it is opened), as it is less concentratedly sweet than these others.
Acidity and dryness also discourage bacteria. Vinegar, with a pH ranging from 2.4 to 3.4, is too acidic to be friendly to bacterial growth, so you ordinarily need not refrigerate it, and it will last safely on your pantry shelf for as long as a year. (But see the book.) Pickling and brining use a potent combination of salt and vinegar or other acid to preserve and flavor foods at the same time. Nowadays we refrigerate our pickled foods after opening them so as to keep them crisper and better-tasting. But pickles always used to be stored in the pantry-in the pickle barrel or jar-and some stores still sell pickles from the barrel, at room temperature.
Meats such as bacon and ham are still sometimes salt-cured (and sometimes are both salt-cured and smoke-cured, smoke being another "natural" preservative). Cured meats last longer than fresh meats, but all meats are such desirable homes to bacteria that they must be refrigerated even after curing to keep them safe.
Because dryness is antimicrobial, flours, mixes, pasta, rice, and dried beans may all be stored in the pantry. Molds, however, may afflict dried foods if your pantry gets too humid.
Foods containing enough alcohol, a general disinfectant, can also live long on your pantry shelves. It is the presence of alcohol that keeps your vanilla, almond extract, and other flavoring extracts, as well as alcoholic beverages, safe for long periods on your shelves without refrigeration.
The Art and Science of Keeping House
By Cheryl Mendelson
Scribner, November 1999
896 pages, 225 black and white line drawings
Reprinted by permission.
This page created March 2001