From rotting potatoes to ripe manure, odors from compost materials are the bane of the composting world, sometimes even leading to intense friction and shouting matches between formerly friendly neighbors. Compost odors typically occur as a result of excessive activity from anaerobic bacteria, which proliferate in the compost heap in the absence of oxygen, according to the University of Illinois Cooperative Extension. Too much moisture in your compost further contributes to odor problems by suffocating the oxygen-loving bacteria. You can compost without odor issues provided you add organic waste carefully and make the commitment to turn your compost pile regularly, typically on a weekly or biweekly basis.
Select the nitrogen-rich organic waste for your compost heap or bin with care. When possible, avoid food waste that has already started decomposing. Opt for forage-based organic waste, such as grass and weed clippings, to provide most of the nitrogen-rich ingredients in your compost heap.
Prepare moist, nitrogen-rich organic waste adequately when you first build your compost pile. Slice thick chunks of fruit and vegetable waste into small pieces that measure less than 1 1/2 inches in diameter. Chop manure pieces into similar-sized chunks with a hand trowel. Mix these potentially problematic nitrogen sources with equal amounts of carbon-rich materials, such as wood shavings or dead leaves, to provide more space for oxygen flow in between the waste particles.
Mix your compost layers together with a manure fork at least once every two weeks to introduce fresh oxygen to encourage the microbial action of the aerobic bacteria in your compost heap. Shift the compost from the center of the pile to the edges; move the compost materials along the edges of your pile to the center of the heap.
Check your compost moisture content every two days. Squeeze a handful of the composting materials tightly; you should only be able to wring out one to two drops of moisture. Add extra carbon-based waste, such as dead leaves, to soak up any excess liquid if necessary.
Opt to use a compost trench for large amounts of particularly odorous waste materials, such as partially rotted food and liquid cow manure. Dig an 18-inch-wide trench that is about 12 to 18 inches deep. Make sure the compost trench is long enough to contain all the organic waste you wish to compost. Spread the organic waste material across the base of the trench and fill in the top 6 to 8 inches of the trench with plain topsoil, packing it down slightly to minimize your chances of having large animal pests, such as raccoons, dig up the waste.