The contents of a compost pile become rich humus through the work of billions of tiny microorganisms. Give them a little time, heat and moisture and they can turn almost anything back into soil. But like any other organism, they need energy to do their jobs. If your compost pile is cooler than it should be, its resident microbes may need a boost of energy or some new recruits to get back to efficient decomposition.
Add a few handfuls of garden or potting soil to your compost pile, or about 1 percent of its volume. All garden soils contain the microorganisms responsible for decomposition. By adding a fresh supply, you will energize your compost.
Add a few handfuls or 1 percent by volume of organic fertilizer like cow or horse manure or an equal mixture of used coffee grounds, grass clippings and dried leaves. These materials contain high amounts of nitrogen which fuel the microorganisms in your pile.
Turn your compost pile after each addition and at least once weekly (or whenever a compost thermometer reveals a drop in the compost pile's temperature). Microorganisms need regular influxes of oxygen to do their job properly.
Move your compost bin into direct sunlight. The optimal internal temperature for a compost pile is between 135 and 140 degrees Fahrenheit. Moving it into the sun will help keep the compost pile warm and the microbes hard at work.