Under the correct conditions, according to a study by the University of Hong Kong, it takes approximately 60 days to turn pig manure into mature composted materials and during the process, possible bacteria such as Salmonella sp., can be eliminated. The composting process consists of creating the right environment for the breakdown of the materials, which requires the right types of materials as well as moisture and oxygen.
Place a layer of straw or dried leaves as the first layer in the compost bin. Make this layer a few inches thick, depending on how much of these dried materials you have. Shredded paper, wood chips, crushed branches or other "brown" materials can be used for this layer.
Spray the layer with water using a garden hose, moistening the dry materials. There is not an exact amount of water that should be used for this process but an ample amount to dampen all of the materials is recommended.
Add a layer of "green" materials such as fresh grass clippings, kitchen vegetable scraps and fruit scraps. This layer can be about 1/2 as thick as the previous brown layer.
Add a layer of pig manure. This layer should be about as thick as the green manure layer.
Add a thin layer of soil and spray down the pile with water from the garden hose again, moistening all of the new materials added.
Start the layering process over again with brown materials, then green, then manure and soil spraying each layer with water when complete. The final compost pile should contain two to four complete layers of the various materials but should also leave enough room in the compost bin to allow for turning the materials.
Mix all the ingredients in the compost bin using a pitch fork, shovel or tumble using a tumbling handle, if your bin is equipped with that feature.
Turn the compost once every two weeks or every week during the summer, when temperatures in the compost bin reach higher temperatures. As the materials break down the compost will reach temperatures over 110 degrees F and an active pile should be approximately 135 to 145 degrees F in the center for optimum decomposition. Turning the compost allows materials to remix themselves and to form air pockets that are necessary for the growth of the decomposition microorganisms.
Spray water on the compost pile every few days or once a week, as needed to maintain a damp consistency. To determine if there is enough moisture, pick up a handful of compost and squeeze. If a few drops of water come out, it is at the right moisture level.