Anaerobic composting or composting without the presence of oxygen has been practiced for centuries.
Records indicate that the Chinese are the oldest known civilization to practice this form of composting to fertilize their rice paddies.
In more technical terms, anaerobic composting is composting organic materials, using living anaerobic organisms such as bacteria in an environment that has no oxygen present.
This is the same process you will find occurring in nature as peat bogs and marshes.
Unless you happen to have access to a large field of water you are going to have to find another way to create your anaerobic compost pile.
While most composting experts will talk about not letting your compost piles get too wet or they will rot, anaerobic composting requires approximately 70% moisture levels in order for it to work properly.
The Standard Compost Pile
You can turn your current compost pile into an anaerobic one quite simply and effectively by adding plenty of water.
Yes I know we have spent hours telling you how important it is to maintain moderate to low moisture levels, but with this type of composting you need to remove the oxygen from your compost pile.
The water will drive out the oxygen and keep it out if you keep the water level high enough.
By covering the pile to help keep in the moisture, you will end up with a slimy mess, which indicates that it is working properly.
You should however, be prepared for a very odoriferous (don’t you love this word – I can almost smell it) compost pile. This is really more suitable to households with larger tracts of land where the aforementioned odoriferous pile can be placed away from the house or the neighbors.
This is not really a household practise but keep reading because there is an easy way to compost anaerobically at home. Just skip down to Bokashi Composting if this is what you want to read about.
The Submerged Pile
This method of creating anaerobic compost is very similar to that which is has been in use by the Chinese for centuries and involves keeping your compost under water.
For this you will need a large tank, plastic pool or tank that is big enough to hold your compost and then be filled with water.
As your compost pile decomposes the odors are trapped in the water. While slightly more involved than a standard anaerobic compost pile, your neighbors will certainly appreciate it. But … this is really for the experts.
The Big Bag Theory
You have probably seen this method in use in the local farmers’ fields, this would be the long white bags that lay in the fields over the winter.
This could be for you and is simple.
You need a large heavy duty plastic garbage bag. You first layer the bottom of the bag with soil, then add your compostable materials and add enough water to make everything moist.
Seal the bag so that no air can get in and roll it to get things started and then leave it alone for 6-8 weeks.
No Hole in My Bucket
Off all the different forms of anaerobic composting, the bucket method is perhaps the easiest and least offensive.
This is a long term project and will take up to a year (yes, commitment is required but then again, a year goes so fast these days) to create the compost you are looking for.
You simple cut the bottom from a five gallon bucket and plant it a few inches into the ground.
You then fill it with your scraps and organic waste, place the lid on it and forget it for a year.
Do not open until the year has passed or you will let in more oxygen and ruin the process.
As you can see a fair amount of patience is required for this method. At the end of the year you will have perfectly usable humus. All of these forms of anaerobic composting work well, some will produce more compost than others, while at the same time creating a rather smelly situation.
It is an anaerobic form of composting using a bucket but easier to manage than the hole in the ground method and with much faster results.
The good thing about Bokashi composting is that meat and dairy which are banned from traditional composting are fine to use in the Bokashi system which composts anaerobically.
The scraps are put into a bucket and then covered with some inoculated bran (see picture).
When the bucket is full the lid is sealed shut to ensure no oxygen enters the bucket. It is left for approximately 10 days.
The commercially made systems have a spigot (look at the picture) at the bottom of the bucket and every few days the leachate needs to be drained from the bucket.
This is a link to an experiment with Bokashi that may interest you if you want to see more about how it actually works.
It is also well worth reading the comments at the end of the post.
Alert! You will notice that it is a post from 2008 which seems light years backwards in the world of the internet considering it is now 2015, however remember Bokashi composting is hundreds of years old and there hasn’t been any dramatic changes since 2008.