Mellow Compost Lab

Home vs. Industrial Composting

Home composting complements industrial composting.  Here we cover key features of home composting and contrast with its industrial counterpart.

Home composting is an attractive proposition as it produces good material in situ. And at the same time it fosters local responsibility for waste management by reducing waste collection and transport costs.  It can also bring in the satisfaction of making “your own” compost; and have plenty of it for free. Industrial compost making has obviously some different objectives, including large scale (volume) and shorter periods of production to make it economically viable. Here we outline the key differences between home and industrial composting. See below our experience on home versus bought compost

Home composting might also be referred to by household or domestic composting; the latter in particular to contrast it with its industrial or large scale version. The  main characteristics to compare home and industrial composting are:

  • Volume of waste processed
  • Controlled environments (conditions)
  • Particle size
  • Time allocated
  • Effort allocated
  • Hot and cold composting
  • Availability rate  of waste material

Volume & mix of waste

Industrial composting relies on the availability of  large scales of waste on a regular basis. This could be in the tens of thousands or litres (or tons) per fill-up. These industrial facilities have their own assured supplies. In contrast home composting is in the order of magnitude of tens to hundred litres per fill-up.  A compost pile heats up when there is a critical mass/volume in the container (from ~ 1 m3). A home facility is likely to take a few months to fill-up a container in the Summer and even longer in cool seasons;. Clearly these indicative figures depend on garden size and material available. However, most home bin containers have sizes between 220L and 450L; so that serves to give an idea of expected volumes produced by homes.

Controlled environments

Industrial composting is subject to many aspects under a controlled environment; from the right mix of brown and green; getting the C:N ratio; managing other conditions such as temperature; moist level and aeration (Oxygen). It is more difficult to get a very accurate good handle on the making of home compost.

This is about home composting; not large (or industrial) scale composting. So it has its own characteristics including the volume of IW available, frequency of topping up a bin and time available to undertake the end-to-end cycle; the approximations with various components added. MCL process in the range of 2,500-5,000L of waste per year.

Particle size

Small size of green and brown material interacting (with moisture and air) helps physical contact and speeds up chemical and biological reactions and contributes towards finer compost texture. In industrial composting, shredding is systematic by mechanical or other processes outputting consistently small particles. In home composting, it all depends on time and effort  applied to cut these. Large chunks of waste will contribute to a slower reaction and lumps of compost at the end of the process, even with stirring.

Effort allocated

Industrial  composting benefits from a high level of automation, controlled planning (and schedules), large scale tools and mechanised machinery to manage its end to end life cycle. In contrast, in home composting, the level of effort assigned to compost making varies widely. One side of the spectrum could be as simple as “drop & forget”; leaving the pile to decompose over time; perhaps stirring from time to time and keep adding to the pile. The other side of the spectrum could have the avid compost maker keen to attend to the pile regularly (like we do at MCL).  Obviously, the effort provided in home composting will contribute significantly to the speed of the finished material as well its quality

Hot and cold composting

The resulting temperature  from all the industrial compost making variables mentioned above will provide a consistently high temperature (~65℃) under which the waste will decay leading to speed of decomposition and refined compost material. The availability of large (bulk) shredded material aid greatly towards this. Whereas in home composting, the temperature ranges under which the waste is decomposed varies significantly on the volume added, particle size and mixing frequency.

Our usage and experience

On the quality of compost: We have been using home made compost since 2013 and are really happy with its quality. Between 2012 and 2015 we purchased just over 25 bags of 120L (~3000L) general purpose compost  during the setup phase of our garden (41 m2 of raised beds and borders/plants). By 2015, we stopped buying compost and became totally self-sufficient. So far, our garden (inc. house plants and seed trays) has consumed over 11,500L of home made compost. We are really satisfied with the vegetables, fruits and plants growing in this medium. If anything, the growth is certainly better these days than the early years (2012-2015) when we used the shop-purchased compost. Note that could be down to a better experience in gardening over the years. So in summary, we feel our home made compost is probably as good as the one we bought in the past.