Why is compost moldy?

Compost only is moldy when proper procedure isn't followed. For the breakdown of compostable materials requires certain levels of air, moisture, and temperature; and the regular turning of the pile. Mold may result from the failure to meet and keep the appropriate air, moisture and temperature levels; and from the failure to turn the pile regularly. Properly processed compostable materials end up as dark brown, fresh-smelling, organic material-rich soil.