Kahawa Estate Coffee

The ABC Science Show visits Kahawa Estate

ABC Radio National’s Robyn Williams visited Kahawa Estate to find out about the benefits of biochar and why Australian coffee tastes so good.


Kahawa Estate Coffee

Jos Webber of Kahwa Estate Coffee inspects his biochar research trial. (Photo: Kim Honan)

Adding charcoal to soil regularly over a long period has been shown to radically improve soil and its ability to support crops. Organic carbon in soils is lost as forests are replaced by crops. Gradually over time, the soils decline. Adding biochar is a remedy.


It’s a method that has been employed by some Aboriginal and South American cultures for centuries. In South America people created charcoal and added it to soil, deliberately, knowing that it enriched soil.


The NSW Department of Primary Industry is running biochar experiments in a range of locations. Jos Webber runs Kahawa Estate, a coffee plantation on the north coast hinterland of NSW, and shows Robyn Williams his biochar experimental plots. Some field trials show significant sequestration of carbon dioxide. Lukas Van Zwieten and Stephen Kimber describe changes in soil chemistry when biochar is added.