Composting kitchen waste

The bin we have chosen to trial is the Hotbin, see more information here. There are other systems around which range from an electrical powered system for use inside the kitchen to plain plastic bins for use in the garden.

Why did we choose the Hotbin?

  1. It is an insulated bin designed for hot composting i.e. to heat the contents to 40°C – 60°C.
  2. It is intended for kitchen waste although it will also take garden waste.
  3. The price is reasonable compared to the £400+ for some insulated rotary bins.
  4. The product looked well thought out.

Please note, we have no commercial interest in this product and purchased the bin through the normal channels without any discount or inducement.

The instructions say start the bin with a minimum of 40cms of kitchen or mixed kitchen/garden waste. It also recommends using the supplied ‘winter heater’ which is a plastic bottle filled with boiling water and placed in the centre of the contents. As the weather has turned very cold we used the heater.

The first fill consisted on kitchen scraps, some garden waste, shredded paper and the bulking agent (composted bark) supplied with the bin. The recommendation is not to open the bin again for 48 hours to allow the heater to warm the contents and get the bacteria busy.

Update 23 Jan 2013
It has been a couple of weeks since the bin was delivered and we started filling it. The instructions say to add material until it covers the door. We did not have enough kitchen waste do that but added all we had and did not expect anything to happen. Today I removed the snow from the lid and noticed the thermometer was reading about 8C. The last two weeks have been cold with the daytime max not above zero so I was surprised to see the air inside the bin was much warmer. There could only be one reason, the compost was working and producing heat.

A quick trip into the house and the additional thermometer was inserted deep into the compost. The reading was 30C, the compost had started itself without anything other than a good mix of  ‘green’ and ‘brown’ material and the bulking agent (composted bark) supplied with the bin. I have reduced the air flow slightly as suggested in the instructions to see if the internal temperature will increase.

I have made hot compost for many years and sometimes it is hard to get going especially in winter. The last two weeks have been very cold with lots of snow here. That is not unusual as we are around 330m (1000ft) above sea level in a valley that is open to the east so the cold winds really have an impact. That leaves me impressed that the Hotbin has worked so well!