Beneath this apparent simplicity of leaving a biodegradable waste pile out in the open and turning it every so often to create compost, there is an ongoing complex biological process.  Unless what is occurring is well understood and controlled, compost quality could be compromised.  For aerobic composting to occur, certain conditions need to be created and maintained.    Properly managing and monitoring variables like oxygen, humidity and temperature are essential to producing a premium, stable and nutrient rich compost. In addition, if proper aerobic conditions are not maintained, overbearing vile odors can be released into the atmosphere. 

Typically, the larger the waste volume, the more complex it is to maintain consistent conditions for the composting mass.   An effective composting system should be able to effortlessly produce a consistent end-product, without odors and vector attraction, require minimal labor input and maintenance, and should not require large amounts of valuable land.

Each application will require a different component makeup of compost.  The following should be used as general guidelines:

Qualitatively speaking, mature quality compost is a humic substance, dark brown in color, even textured and having an earthy aroma.   However, sometimes looks can be deceiving.  Unless it is known what process/method was used to create the compost, it may not be free of pathogens, protozoa and weeds seeds.  In addition, it may be lacking in beneficial nutrients, micro-organisms and enzymes, or it may not be consistent or stable.   

If the composting mass has not been controlled, monitored and agitated properly it is possible that thermophilic conditions ( 104°F – 160°F ) were not reached for at least 3 days, thereby not destroying pathogenic bacteria, protozoa and weed seeds.   Conversely, if the temperature is allowed to rise too high, beneficial micro-organisms - one of the most important elements in a finished compost - will be destroyed, thereby significantly reducing the quality of the end product. 

Consistent oxygen flow is also essential as this is the ful that the active bacteria need to live.   Proper agitation is therefore an essential part of the process.   Over agitating disrupts the composting process and under agitating may not allow for appropriate airflow.   

The time required for satisfactory stabilization depends primarily on the initial C:N ratio of the feed stock, particle size, maintaining optimal aerobic conditions and moisture control.

A good compost is typically comprised of the following:

Component	Measure
Dry weight (Indicates moisture content):	45:85%
Active Bacterial Biomass:	15 – 25	micrograms/gram
Total Bacterial Biomass:	100 – 3000	micrograms/gram
Active Fungal Biomass:	15 – 25	micrograms/gram
Total Fungal Biomass:	100 – 300	micrograms/gram
Hyphal Diameter:	3.0+	micrometers
Protozoa:
- Flagellates:	10,000+	per gram
- Amoebae	10,000+	per gram
- Ciliates	50-100	per gram
Nematodes:	20 – 30	per gram

Again, this combination can vary depending on the composition of the feedstock and the specific application the compost is to be used for.