Letting Johanna and Bokashi do their thing

This week we caught up with Adam and Hayley who are first-time users of a Green Johanna.

They set up their Johanna in their back garden back in April. The couple had been keen to compost for years and had tried a couple of times with different composters but been disappointed with the results.

 Their reasons for composting were that they wanted to recycle their food and garden waste as well as produce their own compost to grow their own vegetables.  

Adam said:We have quite a big garden and a lot of garden waste to put to good use, such as branches, leaves etc. We also wanted a good place to put our food waste. We grow potatoes and other vegetables in the garden in large planters.’

They’ve been using the Johanna with an insulating jacket and in combination with a Bokashi bin. Bokashi bins are waste containers that ferment – rather than decompose – food waste thanks to the addition of beneficial anaerobic microbes in a spray or bran. Once full, the bin is sealed and left to ferment for around two weeks to become a pre-compost mixture which is then added to a composter or buried in soil in the garden.

  ‘It’s become a really useful part of our composting process,’ said Adam. ‘We put all our food waste straight into it and give it a few sprays of Bokashi spray, then once it’s full and has been left to ferment we transfer it to the Johanna.’

ABOVE: Contents of the kitchen caddy added to the Johanna.

 ABOVE: The Bokashi bin’s contents added to the Johanna. The contents of a Bokashi bin after two-weeks’ fermentation don’t appear much different; there will usually be a pickled smell. When added to a compost bin the pre-compost mixture acts as an accelerator – heat increases and the composting process speeds up.

Adam and Hayley are a household of two, both vegans, and it takes around one to two weeks for them to fill the Bokashi bin. Their waste is mainly vegetable scraps along with some beans. They then use their  smaller kitchen caddy to take food waste to the Johanna ‘whilst the Bokashi bin is doing its thing.’

They used some Bokashi bran in the Johanna when they were starting out to give the contents an initial boost but haven’t felt the need to use more since. Some people use it throughout the year to keep giving their compost an accelerating boost thanks to the presence of beneficial microbes in the bran.

While they haven’t used a thermometer to check the compost temperature, they’re having a lot more success with the Johanna than with other composters they tried in the past.

 ‘The Johanna is much better built and seems to be working faster at breaking down all the waste,’ said Adam. He added there had been no problems with flies or rodents.

Their garden waste provides them with more than enough carbon content (Browns) but they have also added shredded waste paper.

If you lack garden waste it’s a good idea to store shredded paper or cardboard, wood chips or sawdust in lidded containers nearby so that they can be added at the same time as adding food waste to get a good balance of nitrogen-rich Greens and carbon-rich Browns as compost materials You may be able to find a local tree surgeon who is willing to drop wood chips off for free.

So far, Adam and Hayley are happy composters and are waiting for the big reveal – accessing their first batch of compost! Watch this space…

Taking compost from the Green Johanna


At Great Green Systems we’re always keen to share our and our customers’ experiences of composting with the Green Johanna. This weekend we opened up a Green Johanna that we have been trialling with great results.

This Green Johanna was used from mid-September 2022 to mid-February 2023 with the insulating jacket permanently installed.
100% of the cooked and uncooked food waste from this household was recycled in the Johanna. There were between 2 and 4 people in the household during this time, with up to four more visiting through the Christmas and New Year period. The amount of waste diverted to the residual (grey/black) wheeled bin fell to less than 50% of the bin capacity (ie less than 120 litres) per fortnight compared to previous usage. Over the Christmas period, when bin collections were suspended for a week, the residual bin comfortably coped with three weeks’ worth of general waste.
The fermented contents of several 14-litre Bokashi bins that were accepted from relatives who don’t have their own compost bin were also decanted into the Green Johanna.
The food waste was liberally mixed with carbon-based materials, mainly autumn leaves and wood chips, and treated once per month with Bokashi bran to accelerate the composting process.
Using this method, we consistently achieved compost temperatures of 30-60 degrees Celsius even through the coldest winter temperatures. All the food waste generated from the household was comfortably accommodated by the composting system.

Saving the top section to go back into the compost bin

Compost can be accessed by unscrewing the hatches at the bottom or, since the Green Johanna is a modular unit made up of circular rings, the upper sections can be removed leaving an impressive tower of compost. As you can see from the photos, we chose the second route as we wanted to take a lot of compost out at once.
We removed the top sections of compost that are currently decomposing (taking care not to squash any worms) and placed these on an old wipe-clean tablecloth kept for this purpose until we were ready to put them back in the bin to continue the breakdown process.
More than half of the composter contents were removed for soil replenishment and other garden uses, with the remainder being returned to the Johanna for further composting.

Topping up planters with compost

To purchase a Green Johanna Complete Bundle, including Insulating Jacket, click here:
Green Johanna Complete Bundle – Great Green Systems
To upgrade your existing Green Johanna with an Insulating Jacket or Complete Accessory Set, click here:
Green Johanna Insulating Jacket – Great Green Systems
Green Johanna Accessory SetGreen Johanna Accessory Set – Great Green Systems
To combine your Green Johanna with indoor Bokashi Bins, click here: Bokashi Bin By Maze – Great Green Systems
To improve and accelerate your Green Johanna composting with Bokashi Bran, click here: Bokashi Bran 1kg – Great Green Systems

Spare Parts