Green Johanna with Insulating Jacket

There are several reasons for a composter to stop working:
* The contents may be too wet or too dry. The ideal consistency is like a wrung-out sponge. If you take a large handful of the compost and squeeze it, only a couple of drops of liquid should come out. If it is too dry, add chopped-up nitrogen-rich materials, such as food waste, or gradually add some water from a watering can with a fine rose spray. If it is too wet, add carbon-rich materials and aerate well.
* A lack of material in general will always slow the process down and in some cases stop it completely. Add more waste materials, maintaining the carbon-nitrogen balance, to start up the process again.
* The mix lacks oxygen. Give the bin a really good stir and add some finely chopped twigs or wood chips to help with aeration.
* Cold weather and a poorly-fed Green Johanna can bring a halt to the composting process. In winter make sure that you are adding content regularly (chopping items up) and the Johanna is wearing an Insulating Jacket.

The time required for waste materials to break down into compost depends on:
* the volume of material; a greater volume will maintain the thermophilic stage for longer.
* the particle size of the inputs; smaller items break down faster.
* the amount of mixing and aeration.
Depending on conditions, the usual time using the Green Johanna is 4 – 6 months. Using the Insulating Jacket, temperatures will remain high for longer and compost will be produced quicker.

Yes, if you add paper product waste (shredded paper and newspaper/ripped-up cardboard, toilet roll tubes, egg cartons) and/or sawdust and wood chips. These provide carbon to balance the nitrogen in food waste. It would be useful to store these materials so you have carbon content readily available for each time you add food waste. Most people find they have more nitrogen-rich content than carbon-rich so they stockpile carbon sources so they have it ready for when needed.

Cardboard should be torn up (with labels and stickers removed), paper and newspaper should be shredded or scrunched up. Toilet roll tubes and corrugated egg carton bases can be left whole in order to create air pockets.

Wood chips are useful as they hold structure and create pathways for air. It can be helpful to have a bag of wood chips next to the compost bin. After emptying the kitchen caddy, add a caddy of woodchips etc.

If adding large amounts of sawdust, take care to separate it out in order to avoid clumps forming.

As micro-organisms break down waste and multiply, they generate heat. As the temperature in the compost fluctuates, the types of micro-organisms present also change. This diversity is important. How warm the compost gets depends on what you have put in together with levels of oxygen and moisture. Different micro-organisms work at different temperatures.

There are three major phases in successful composting – mesophilic/thermophilic/maturation.

The mesophilic phase occurs at the start when decomposition is carried out under moderate temperatures by mesophilic organisms. The thermophilic phase occurs as the temperature rises and various thermophilic (heat-creating) bacteria carry out decomposition at temperatures of 50-60 degrees Celsius. The maturation phase occurs when the temperature starts to decrease as the supply of high-energy compounds dwindles and mesophilic bacteria once again predominate.

The optimum working temperature in the Johanna when wearing the Insulating Jacket will usually be around 40-60 degrees Celsius. If temperatures reach 70 degrees, steps should be taken to lower the temperature, such as by removing the Insulating Jacket and increasing ventilation by twisting the lid to the maximum setting. Temperatures of over 70 degrees will be too hot for the micro-organisms to survive.

The Green Johanna is designed for a household of up to five people and can accept the compostable waste produced from an average garden. However, since this is extremely variable, if you believe you are filling it too quickly it would be recommended to have a second Johanna. A garden produces less waste in winter, so if you have space you could store some garden waste (such as dead leaves) to layer in with food waste during winter.

A well functioning compost bin should hardly have an odour. Any smell should be fresh and earthy. You have probably added too much nitrogen-rich waste, such as grass clippings or food waste. Remedy this by adding plenty of carbon-rich garden waste (shredded twigs/branches/autumn leaves/wood chips), shredded or scrunched paper and cardboard. You also need to get oxygen into the mix by stirring well with the aerator stick. Take a small batch of the finished compost or half-composted material from lower down the unit and sprinkle over the top.

If you have large amounts of fresh grass clippings (nitrogen-rich) this should not be added all at once and should be well balanced with carbon-rich materials such as shredded autumn leaves and newspaper.

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