There are several stages involved in the industrial composting process:

>> 1st stage: Receiving and storing organic matter
This stage does not last very long

>> 2nd stage: Preparing waste
This might involve sorting, crushing, sifting and mixing waste to obtain the best possible composition for biological transformation.

>> 3rd stage: Fermentation
This is when the composting process really begins The organic matter is placed in stationary or upturned windrow. The windrows are sometimes placed inside a closed system (such as a chamber, a tunnel, or silo) with either natural or forced ventilation.

>> 4th stage: Sifting
Sifting can either be done before or after the maturation stage. It makes is possible to obtain the desired granulation depending on the use for which the compost is intended.
Matter more than 2 mm in dimension (sometimes more depending on the quality of the final product), which are a result of human actions or which have an organic or inorganic component such as metal, glass or synthetic polymers, must be removed from the compost.

>> 5th stage: Maturation and storage
The duration of maturation depends on the duration of the preceding fermentation stage. Compost maturity is an important factor in determining its quality. There are many methods used to evaluate compost maturity but many of these are still in need of improvement, and the complexity of interpreting the results is a problem when choosing a method. Current knowledge means it is advisable to use several indicators when measuring compost maturity.

Click here to find out more about evaluating compost maturity: recommended tests...