Using a compost bin is the most effective way of managing the composting process, so check the results of our expert tests to see which one to buy
The bin you use for composting can make a big difference to the speed and success of the process. Our latest tests have uncovered the best and worst for the job. Composting is a great way to recycle garden and kitchen waste to make soil improver that you can use as a mulch.
On a mission to find the compost bins that are easy to use and efficient, we tested a total of 12 different models. Included in our rigorous tests were popular compost bins from big-name brands, including Eco King, Grange and Thermo-Star.
What are the benefits of using a compost bin?
Composting is a natural recycling process that makes good use of what might otherwise become waste, and the finished product is one of the best and simplest materials for improving your soil.
Through our trials over the years, we’ve found that using a compost bin is the most effective way of managing the composting process and that the type of bin you use can make a big difference.
Best Buy compost bins – a closer look
Hotbin 200L – hottest on test
The average temperature inside the enclosed and insulated Hotbin* was at least 6°C warmer than any of the other bins. It went up to 46°C at times, and as a result the rotting process was the fastest in our trial. It was also easy to fill and empty. If you keep filling it and using the compost regularly, it’s capable of giving you a lot of good-quality organic matter in a short space of time. *Hotbin and Hotbin Mark II: Since this test began, the Hotbin we included in the trial has been replaced by the Hotbin Mark II. However, Hotbin told us that there is no difference in the way the Mark II unit operates – it simply offers some space-saving in terms of the hinge redesign and also the ability to capture most of the liquid from the bin more easily using the built-in tap. We’re therefore happy to make the new version a Best Buy.
Eco King 600L Composter Bin – large capacity
This big plastic bin would be ideal if you have a lot of waste. The large hinged lid makes it easy to add material and a removable door at the base means finished compost can be taken out easily, too. Small holes in the sides help with air circulation and it’s well insulated; we found that the compost kept up a good temperature. The bin produces good compost and, apart from one broken hinge, proved robust.
Green Johanna – speedy composting
This is another enclosed bin for hot composting. We found the average temperature of the contents was slightly lower than the Hotbin over the course of the trial, but the material we added started to settle and rot almost as fast and it’s certainly faster than most of the other bins. It produces plenty of good-quality compost, which can be removed through a small door at the base, and its large top lid makes it easy to add material, too.
Recommended compost bins – a closer look
These bins are also well worth considering, although they weren’t quite as convenient or effective as our Best Buys
Ecomax Black Compost Bin – budget-friendly and efficient
A simple plastic bin, this is an economical choice that makes good compost. It’s robust, but light and easy to lift off if you want to turn the contents. Plus, it has a large lid for easy filling and a door at the base to get the compost out. The composting material stayed moist and reasonably warm, which meant that although it took a little longer than in our Best Buy bins, it rotted down well.
Thermo-Star 400L Composter – easy to use
Scoring highly for convenience, this bin is easy to put together and to fill with material. Finished compost can be removed by raising the side bars and taking out one of the bottom panels, which we found easy to do. The plastic walls have ventilation holes which help with air circulation and the rotting process is good. However, the material has a tendency to dry out at times and needs to be watered.
How we test compost bins
We chose compost bins for the trial that represented the most common types available to buy. We used three bins of each product and arranged them in three separate blocks, so none of the same type of bins were located near each other.
To fill the bins, we collected soft green and brown material, and mixed it thoroughly in 50:50 proportions. Each bin was filled to half its capacity in April 2019, then every month was refilled with enough material to comprise a quarter of its capacity.
Filling stopped in September 2019, resumed in April 2020 and the trial ended at the end of July 2020. The contents were turned (or stirred where the bins weren’t easily emptied) twice in the first year in July and September, and once in the second year in late June, and the compost was watered if it dried out.
Assessments of how much the compost had settled and started to rot and a temperature check were carried out every two months.