Core principles of hot composting

Tuesday, 3 July 2012  |  HOTBIN Composting

How the HOTBIN works

What happens inside the HOTBIN is composting - all composting obeys the fundimental laws of nature. It is dominated by bacteria - 'happy' bacteria deliver fast and successful composting.

Bacteria are at their happiest when they have:

Bacteria need waste to eat. No waste = No bacterial activity = No heat produced.
Bacteria digests different wastes at different speed. Lots of easy to digest food results in fast quick heat release, slow to digest waste results in slow heat release.

Core Compost Principle - Food

Bacteria need water to both grow and to help with digestion. If there is too little water the bacteria are unable to grow; if there is too much water, the waste becomes soggy and it block the air flow which restricts the oxygen the bacteria need.

Core Compost Principle - Water

Aerobic bacteria need oxygen. If there is not enough oxygen, their anaerobic cousins take over and create a stink and release methane (X24 GHG potency!).

Core Compost Principle - Oxygen

Bacteria digests waste 32 times faster at 60°c than at 10°c. As a rule of thumb, using 30 days in a month, if it takes 12 months in a cold heap at 10°c it will take 12 days in the HOTBIN running at 60°c.

Core Compost Principle - Warmth

Bacteria Happiness


What are the core principles of composting?

Composting is a natural process. It will happen under a huge range of environmental conditions. However, to get it working fast, you need four key conditions (food, warmth, oxygen and water) to be optimal. The four conditions are outlined in the Composting Core Principles diagram below.

How does the HOTBIN work?

It helps you manage the four conditions. It retains heat, controls airflow, extracts excess water (as steam). We have a PDF transcript of our talk at the Edible Garden Show which covers the conditions in more depth.