Super Composter Tester Update - September 2019
All of our testers have taken a different approach to their feedback on our new Super Composter and all of it has been really helpful and is being used to modify the current design so it can be the very best it can be.
Dr Ian Roberts has provided us with some fantastic and very detailed feedback, keeping regular temperature records and details of exactly what has been added to the test bin and when.
Here is an extract of Ian’s feedback.
“Composting when you have the right ingredients in the right proportions is a doddle. However, this situation seldom arises in small gardens. However, I find hot composting is more lenient in terms of input materials although it is important to get it off to a good start.
Materials available to start off my Super Composter were (i) some part-composted waste from my Hotbin (contains some biochar and had reached a temperature of only about 30 degC so never really got going), (ii) grass cuttings that were past their best and starting to yellow, (iii) shredded cardboard using the box the Super Composter came in, and (iv) freshly shredded garden waste, mainly leafy bush cuttings with some long grass, from my neighbour.”
Ian used part composted waste from another hot composting bin, shredded cardboard, grass cuttings and shredded garden waste and mixed all four ingredients together adding a scoop of SoilFixer Compost Activator and recorded a starting temperature of 27°C and locked down the lid.
Less than 24 hours later he measured a temperature of 40°C at a 25cm depth, and60°C at 10cm, similar temperatures at these depths continued for two weeks until Ian had filled his bin.
“Interesting to note that rapid temperature rise to over 60°C at the start of the composting process at all measurement depths even when using less than ideal material (part-composted Hotbin material and over the top grass cuttings). Note that the temperature at 50 cm during the first few days is essentially the base of the compost heap. The gap between 5 and 9 days was when the Super Composter was left unattended and, as expected, all temperatures dropped. However, temperatures picked up at all 3 depths when feeding the bin restarted. Temperatures at 50 cm show a steady decline with time as expected but the top 25 cm maintains a good composting temperature.
“The Super Composter has maintained a good core temperature and even though the bin is full, I’ve been able to add 5-10 L of compostable material nearly every day with problem. “
Once Ian reached day 44 he emptied the compost from his bin: “Measure temperatures in the centre of the heap at 10 cm from bottom (20C), 25 cm from bottom (25°C) and 50 cm from bottom (30°C). Clearly some part-composted material (including shredded cardboard) throughout the heap and some green material at the top. This is to be expected for a first fill. Moisture content is fairly even from top to bottom. Using a spade, take off top 25 cm and put to one side as starter for next composting run. The bottom 50+ cm transferred to conventional compost bin to spend 6 months maturing (i.e. letting the worms finish off the composting process).”
To read previous posts about our testing programme click here.