Posted: Donal Date: August 27, 2019

Why a new composting system?

food waste for composting

In my 15 years working as a composting trainer, adviser, and researcher, I have met so many people who face the same issues with their composting. It’s a smelly heavy mess, they don’t know what is happening inside the pile, and it just isn’t easy enough to use.

The problem for most people, of course, is the type of compost bin they use – either a “Dalek” shape garden composting bin

Plastic compost bin
“Dalek” style compost bin – narrow on top, wider at the bottom, no airflow or permeability

or the compost tumbler type that has become popular recently in Ireland and perhaps other countries also.

A typical compost tumbler – all the moisture that goes in, stays in. Contrary to what some people believe, this is not good at all.

These bins and tumblers do not permit quick or easy composting of the kitchen waste which is our main organic waste issue. They get full, wet, and heavy with smelly rotting food.

A much better solution is a wormery, but even these have their issues. They are often made of plastic and do not breathe or allow moisture to escape. The trays can become heavy and compacted (though not, of course, if operated very well). And if something goes wrong, the worms can be killed, although this is unusual.

A plastic wormery – much better than most other compost bins for dealing with kitchen waste, but the best has yet to come

I decided to make it possible to have effective composting in a small space, by dividing the material into fresh, semi-fresh, maturing, and matured, while making space for airflow and drainage and preventing compaction.

2 box and 2 tray compost system
The box and tray system. Fresh material (a mix of “greens” such as vegetable peelings and “browns” such as sawdust) is placed in the tray, and when the tray is full then the next tray is used. When all trays are full, the material is emptied into the boxes underneath. One box is filled at a time, so that the contents of one box will have matured by the time the other box has been filled.

This system will allow easy management of all stages of the composting process. Every part should be light and easy to lift, and if something goes wrong it is easy to isolate and fix the problem (usually a matter of (1) chopping up food waste material into smaller pieces and (2) adding more brown material such as sawdust, leaf mould etc.).

And that’s it really! A minimum of 2 boxes and trays needed, perhaps 3 or more for a larger output of kitchen waste or pet poo.

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