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Food waste digesters

A food waste digester will dispose of all biodegradable kitchen waste, cooked or uncooked, such as meat, fish, bones, bread, dairy products, vegetable peelings and fruit.

There are two main types of digestor, the Green Cone and the Green Johanna. They are installed in the garden and look very similar to normal compost bins. Both use natural processes to break the food down without producing methane.

Green Cone

This small food waste digester needs to be partially buried in the ground in a sunny, well drained part of the garden.

green cone food waste digesterThe unit uses solar heat to raise the temperature of the waste in the underground digestion chamber. The surrounding soil insulates the chamber. Food waste is broken down into water and carbon dioxide and a little organic residue. Accelerator powder can be added if needed to speed up the process.

You can put about three-quarters to one kilogram of any cooked or uncooked food waste into the Green Cone each day, which is the average amount produced by a family of four. It’s not intended to be used for garden waste.

The Green Cone works all year round. As it produces very little waste residue it should only need to be emptied once a year at most, usually longer.

Available to buy on Amazon Marketplace from greatgreensystems

Green Johanna

This is a more expensive option, but in my view it’s the best of all. It’s a very simple, easy to use compost bin which will dispose of all food waste and garden waste too.turning2green - green johanna hot composter It will recycle the kitchen waste produced by a household of up to five people together with the compostable waste from an average garden.

The unit must be installed in a shady part of the garden and is designed to be filled with two parts food waste mixed with one third garden waste. If you don’t have much garden waste, other carbon rich material such as leaves, sawdust, cardboard or straw can be used.

Waste is broken down by micro-organisms in a hot composting method which produces good rich compost. To maintain food waste recycling all year round a thermal jacket is needed when average temperatures drop below 5°C. No accelerator powder or chemicals are added.

There are two doors at the base to easily remove the finished compost which, depending on the time of year and temperature, will be ready after about four to six months.

The Green Johanna is available to buy from Great Green Systems 

Another system is now available from Hotbin. This is a highly insulated 200 litre capacity bin  designed to operate at between 40 to 60 degrees C. It’s more complicated to use, but the makers claim it will compost kitchen and garden waste 32 times faster than a traditional cold bin, producing finished compost in 90 days or mulching compost in 30 days. Available on Amazon, or more details from Hotbin.


Note: Larger scale food waste composters are available for schools, restaurants and commercial food waste – see Ridan Composters