Root cellars are ideal for extending the shelf life of produce by maintaining low temperatures and humidity conditions, making it possible to prolong their shelf lives by months if not years. Their size and location will have a direct bearing on how long food stays fresh, and its precise temperature and humidity needs depend on what’s being stored there.
An ideal root cellar temperature ranges between 32-40 degrees Fahrenheit; this provides adequate cold protection without freezing out most vegetable crops, while warm temperatures speed decay. Incorporating a thermometer is also highly recommended to monitor this space’s temperatures.
Root cellars can be created without digging: one method involves using a metal garbage can with an airtight lid to construct one in an existing hole, fill it up with dirt, place your produce inside it, cover everything with straw to prevent water seepage in, and keep the garbage can’s lid four inches above soil level. As an alternative option, consider excavating into a hillside instead.
No matter if you choose an underground root cellar or an aboveground berm, insulation is key to ensure its success. When building an underground cellar, cinder blocks or bags of sand make good insulation options that come in contact with soil; for aboveground root cellars spray foam or rigid insulation can also be used as wall insulation materials.
Root cellar floors require insulation as well, using waterproof concrete as the ideal material, rubber mats or even layers of tarp being alternative options. Furthermore, adding an air gap between your pantry and cellar is recommended in order to prevent temperature fluctuations from leading to condensation that leads to rusty lids and rotting wood shelves – another key step towards keeping your root cellar working in top shape!
As with ethylene gas, another source of vegetable spoilage can be the presence of ethylene gas. You can reduce levels by keeping apples and pears separate from other fruits and vegetables, or wrapping them up in newspaper or paper towel for added support in keeping their freshness for an extended period.
Even with proper insulation and ventilation in place, parts of your root cellar could still freeze over. Should this occur, any food stored near vents or exterior doors should be moved away to protect its quality and avoid loss. In general though, this shouldn’t be too serious a concern unless you live somewhere with extreme winter weather conditions – even then it is wise to check frequently on its contents to remove any spoilage promptly.