As the saying goes, everything old is new again, and that certainly applies to the ancient technique of root cellaring. In its most basic form, a root cellar is a cool, dark, usually humid area designed to favor storage conditions suited to root crops. Today, it can be as complicated as a custom-built basement cold room, an elaborate underground cellar with a ventilation system, a corner of a closet with electronic cooling system, or simply a section of a crawl space with shelving. Wherever it is, the space for a cellar needs to be in an area that doesn't get too warm and stays free of frost—a consistent temperature year-round is best. If you live in a very warm climate, you may need to put your cellaring on hiatus for the summer months, and if you're in an area with very cold temperatures in winter, keep the cellar away from an outside wall. Good ventilation is also important to allow for air movement, so choose an area with an adjustable vent or where you can install one.
Cellaring produce is a terrific way to preserve food in its most natural form. Other preserving methods have their advantages—pickles are delicious, jams are scrumptious and make lovely gifts, frozen and dried food is wonderful in its own way—but cellaring allows you to store raw produce with minimal preparation.
Temperature & Humidity
Different produce items have different skin types, so the optimal temperatures and humidity levels for maximum storage life will vary. Controlling the temperature and humidity in the cellar and keeping tabs with thermometers and hygrometers optimizes produce life.
Vegetables such as beets, Brussels sprouts, cabbage, carrots, parsnips, and turnips all do best in low temperature (33° to 40°F) and very high (90 to 95 percent) relative humidity. Some are better in the same low temperature but with high (80 to 85 percent) humidity. These include apples, citrus fruits, leeks, pears, potatoes, and quinces. Others, such as onions and garlic, are better in relatively higher (40°F to 50°F) temperature and lower (60 to 70 percent) humidity. The temperature in a cellar will vary, with cooler temperature near the floor and warmer at the ceiling, but that variance may not be enough. Explore different venting and cooling techniques to make the cellar temperature fit your needs. Keeping it more humid is usually trickier than keeping drier conditions. For simplicity, store produce items that favor similar conditions when you're starting out.