How Ridan Composters work

Ridan Composter in poly tunnel

Why use a Ridan Composter?

Composting is a natural process which will happen as long as the key ingredients of Carbon, Nitrogen, Air and Water are present. However, for composting to take place naturally the conditions have to be just right. It is not always possible to recreate those conditions manually but using a Ridan composter will ensure the conditions are just right. Not only does the Ridan range of composters ensure the conditions are right but they also help to speed up the process.

The Ridan food waste composter uses natural ingredients and processes to create a warm environment in which food waste (nitrogen) and wood (carbon), can mix with air and water. Heat is created when micro-organisms, (including bacteria and fungi) break down the organic matter, food waste and wood. The heat attracts even more hyper active microbes, which make the composting process quick and efficient. This creates the perfect composting conditions.

Temperatures in the composter can reach 40-60°c helping your mixture to compost almost 32 times faster than traditional ‘cold’ composting.

None of our composting machines require power which makes them cheap and easy to operate, Eco-friendly and able to be located wherever you choose.

What can be composted in a Ridan Composter?

All Ridan composting products can compost all food waste and wood. Food waste includes meat, fish, dairy and eggs whether cooked or raw. You can also add green waste from the garden but it is vitally important that you always ensure an equal amount of nitrogen and carbon.

Wood – Carbon Rich

  • Wood chips
  • Sawdust
  • Wood Pellets
  • Wood Shavings

Any of the above can be used bearing in mind the following points.

  • Chip, sawdust and shavings are waste products so can often be sourced locally free of charge from tree surgeons, sawmills or carpenters.
  • Keep it dry, store it close to the Ridan and under cover.
  • Wood Pellets, Sawdust and shavings break down quickly making great compost, larger wood chips take longer to break down making more of a mulch.
  • Wood Pellets work really well. You can order online and they will be delivered to your door. They come in convenient watertight bags and you only need to use a quarter of the amount, however there is a small cost that equates to between £2 and £4 per week, so if you can’t find free carbon, wood pellets are still an excellent option

Food – Nitrogen Rich

  • Dairy, cheese, butter, eggs.
  • Fruit and Veg (including skins)
  • Meat (raw and cooked)
  • Fish (raw and cooked)
  • Bread
  • Salads
  • Pasta, Rice
  • Manure (including rabbit & guinea pig droppings)
  • Plate scrapings, anything edible.

All raw and cooked food waste can be composted in a Ridan, but remember to drain off excess fluids, cut up big chunks and avoid all but small bones. Fruit, veg, greens and prep compost most easily, however starches, meats and dough take longer to digest, much like our own digestive systems, so a mixture of both types of foods is essential.

composting food waste

Can leaves and cardboard be added?

Dead leaves, straw, paper, cardboard and tissue do not offer much in the way of carbon or nitrogen, so will not help much with the initial composting process. However, they are good materials for strengthening the structure of the compost.

For the Ridan Pro range, we recommend not adding these to the Ridan Pro composting machine, but to add them in layers to the maturation box once the initial composting process has taken place.

They can be added directly to the Compostbox range as long as they are thinly spread layers.

Dead leaves, straw, paper, cardboard and tissue are not a valid replacement for wood for either range.

The Ridan Pro System – Daily use

The Ridan Pro System

A diagram explaining how the Ridan Composter works


  1. Prepare and add mixture: Chop up any large chunks of food waste and drain off any excess liquid. Remove the lid at the top and add your food waste, green waste and equal amount of wood chip.

    When the lid is closed it controls air flow into the composting machine and allows steam to escape back out.

  2. Daily turning: The handle is attached to a series of gears to make turning easy. The gears, in turn operate a series of paddles which mixes and aerates the mixture.

    Around 5 turns per day should be enough and this will move the mixture along the body of the composter, pushing out mixture at the other end.

  3. Mix:The paddles help to mix up the nitrogen (food waste) and carbon (wood), introducing oxygen which in turn encourages naturally occurring microbes which all work together to convert the mixture into compost.
  4. Cook: The energy generated from the composting process creates heat which can reach 60c, even through winter months. The heat turns excess water into steam which is released through the lid.
  5. Expel: The mixture is continuously pushed through the machine until it emerges as compost at the outlet where it is collected in a bucket. The final mixture still requires a couple of months to mature before being ready to use. The outlet also allows air flow in and out of the composting machine.


Ridan Pro Maximum throughput

The maximum throughput refers to the maximum amount (in litres) of food waste that can be processed in your Ridan composter. This amount does not include the carbon (wood) materials. The figure quoted for the maximum throughout is the absolute maximum but the optimal amount is significantly less.

You do not have to fill the composter to the maximum or optimal amount. Small amounts can also be composted, just as long as the balance of food waste and wood are maintained.

When your compost is complete

What emerges from the Ridan Pro is not ready to use, it must be matured for at least 12 weeks in a Ridan 900 Maturation Box. Here the composting process will continue, breaking down even further.

Eventually worms, millipedes, beetles and a host of other mini beasts will move in. This is a sure sign that the compost is good stuff and ready to enhance your soils.

Ridan Compostbox – Daily use

compost box logo

Ridan Compostbox daily use

The Compostbox range is designed for home use and is much simpler to operate than the Ridan Pro range.

    Food waste needs to be chopped up and excess liquid drained off.

  1. Both the Ridan Compostbox 4 and Compostbox 10 have a removable lid at the top which is removed to add food waste, green waste and wood.
  2. The mixture can be added in layers with food or green waste first, then a layer of carboard, paper, tissue or dead leaves (not required), then a layer of wood to equal the amount of food / green waste.
  3. There is no need to turn or mix, just ensure the mixture is evenly spread.
  4. The natural composting process will begin and the thermal insulation of the Ridan Compostbox will retain heat but allow the steam produced to escape
  5. Once the process has completed, the mixture will cool which will encourage worms and bugs to move in to refine the mixture.
  6. After about two months, the compost at the bottom will be ready to be harvested.
  7. Continue the cycle by adding more mixture on top