How It Works

If you are new to composting, you may be a bit amazed with the process... and the results. All organic matter that contains carbon will break down naturally. By break down we mean that it goes through a biological process that produces a humus-like material rich in nutrients. When an organic material is put in an environment with the correct amounts of nitrogen, oxygen and water, you have the conditions suitable for composting.

The organic material can be a variety of things: animal wastes, municipal sludge, food byproducts, and even animal carcasses

By using an in-vessel type of composter, you can actively control the recipe (the ingredients you want to decompose), the temperature and the moisture to accelerate this natural process. During this process, the material in the composter reaches temperatures up to 150 degrees Fahrenheit. In less than 7 days the bulk of the biological process is finished.

Once this accelerated process is finished, compost is not completely stabilized. Instead, it is removed from the digestor where it can remain undisturbed for about a month. During this time, the carbon to nitrogen ratio (C:N) in the compost will continue to shift to acceptable levels (typically between 25:1 to 40:1).

There are many types of commercial composting for sale today, most of which fall into the following categories:

Vermiculture: the material must be precomposted first, or the temperatures must be monitored so the worms are not harmed. The worms do add value to the compost with their castings, or waste.

Drawbacks:
- difficult and costly in commercial composting
- worms must be removed from their castings with elaborate equipment
- compost process takes up to a month

Mechanical Windrow: organic material is mixed and then piled in a row. Aeration is provided by turning, or stirring, the pile with specialized equipment.

Drawbacks:
- nutrients can leech out of the pile into the ground, or be washed away and enter the groundwater
- compost process takes 2-4 months
- requires intensive management: testing, turned (mixed), adding moisture
- produces uneven, inconsistent compost
- requires large amounts of land
- unusable during winter months in colder climates
- no way to control odors except by enclosing the pile

Static Pile: organic material is mixed and placed in a pile and left to stand. Depending on the material, this method may require some sort of aeration such as forced air running through tubes underneath the pile.

Drawbacks:
- nutrients can leech out of the pile into the ground, or be washed away and enter the groundwater
- compost process takes up to 6 months
- aeration must be continually adjusted so not to decrease the pile's temperatures
- produces uneven, inconsistent compost
- requires large amounts of land
- unusable during winter months in colder climates
- no way to control odors except by enclosing the pile

In-vessel: Bag: a wide variety of systems generally consisting of bags or containers which are filled with material where moisture and aeration can be monitored and adjusted.

Drawbacks:
- requires some system of aeration
- bags are rarely reusable
- most applications are cost intensive and only possible in very large systems

In-vessel: Drum: our system of composting - organic material is loaded into a rotating drum where moisture and aeration can be monitored and adjusted.

Benefits:
- insulated drum allows the composter to be used year round even in cold climates
- rotating drum continually aerates and prevents uneven pockets during the composting process
- mechanics of the system are very simple and easy to maintain
- yields very uniform compost
- eliminates strong odors within days
- material is isolated from the environment - no leeching or spillage
- the fastest type of composting available today
- extremely compatible - thoroughly tested with all types of animal manure, municipal biosolids, food waste, food processing byproducts, and animal mortality

Skeptical? Consider what the National Resource, Agriculture, and Engineering Service (NRAES) said about