The "Ridan" composter

Installation

The Ridan can be installed anywhere, inside or outside, all it needs is a firm surface to stand on bearing in mind that when full it can weigh up to half a ton.

Dimensions and Capacity

The Ridan is 1.2 meters long, 1.4 meters wide and 1.6 meters high, so ensure that there is enough room around it to turn the wheel, load waste and empty the compost, a wheelbarrow can be used for this.

The machine will take just over 40 litres / 20 kg of waste per day.

Location

Consider where the waste is being generated and where the compost will be used, carrying either very far can become a chore, so think about positioning the Ridan and the maturation box close together.

Also consider that composting can smell; when working properly the smell will be minimal and not unpleasant (a yeasty fermenting smell) but at some point you will get the mix wrong and it will smell bad, so site the Ridan away from neighbours and living spaces. Ridan can supply an optional vent pipe assembly where necessary, to exhaust fumes overhead or outside if required.

Bacteria

Composting cultures will establish themselves in the Ridan over time as long as the right ingredients are present, however a batch of fresh compost introduced from a working Ridan, or an established compost heap will kick start the whole process.

What can you put in?

All kitchen waste food, raw and cooked, the only advice is, don't put in whole fruit, vegetables, large bones, shells or big lumps, chop it small and it will break down more quickly. Also avoid too much liquid such as gravy, custard, soup etc.

The Mix

The proportions are easy to get right very quickly, you simply need half 'brown' material like dry woodchip and half 'green' food waste, so if you put in one bucket of food waste you must also add one bucket of woodchip, it's that simple!

For aerobic composting to happen, Nitrogen (food waste) Carbon (woodchip) and Oxygen (airflow) are required in roughly the right proportions. Raw fruit and vegetable waste compost easily, so it is best to start with these, then add cooked waste when the Ridan is up to temperature.

Hot Stuff !

Composting produces heat and the Ridan controls this using airflow and insulation, it needs to be hot to work so your aim is to see steam rising when you open the lid. It can take a few weeks to heat up, but it will when the conditions are right and then your off, all it will need from then on is a regular supply of waste mix, and a regular turn or two.

If the waste mix and turning stops for a few days or weeks during holidays etc, the Ridan will cool down, but don't worry, the micro-organisms will sit and wait ready for the next feed when they will get to work once again and heat up.

Start Up

Using equal proportions of uncooked waste and woodchip start loading the Ridan through the inlet, along with some fresh compost if available.

Airflow is important, so don't overfill, there should always be an air gap over the waste at the bottom of the loading inlet, always replace the lid as this regulates airflow correctly.

Turn the Ridan at least once a day, one full turn is enough, more is better; as it fills up, place a bucket under the outlet to catch the throughput, initially this can be recycled back into the inlet.

Watch the temperature, it can take two to three weeks for things to get hot and really start working, so be ready.

Rapid composting happens best at temperatures over 50 degrees centigrade, the raised temperature promotes aerobic reactions within the mix giving excellent living conditions for the active microbes. So the first target is to get the mix hot and moist. You will need a supply of dry woodchip in order to get composting quickly, large, dry woodchips work best, we can supply these until you locate a local source.

Free Compost

Gradually as the Ridan gets full, compost will emerge from the outlet so place a bucket or wheelbarrow there to catch it as you turn the wheel, it should be dark, moist and have an earthy smell.

If the waste food has been predominantly fruit and vegetable based you can probably spread it straight onto your garden, otherwise it is better to let the compost mature for a few weeks in a maturation box where it will continue to break down.

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