Aeration
Oxygen is also required by many of the microorganisms responsible for successful composting. Give them adequate ventilation and they will take care of the rest (see Aerobic Decomposition). You can make sure that the bacteria in your compost gets sufficient air by turning the pile often and well. Use a pitch fork, spade or compost aerator to mix your pile. If you’ve got a compost tumbler, you’ve got it easy. Just crank that lever. Don’t aerate your compost and it will break down slowly, resulting in a slimy, dense, stinky pile. It’s also a good idea to turn the contents since it rearranges the decaying material. With a little care, you can move the less decomposed material on the edges to the middle of the pile to heat up.