I have been following Bokashi composting for a number of years and never really understood what happens during the fermentation process. Ask people what bokashi is and they reply with, it’s fermentation. Ok, what is fermentation? Few can take the discussion further especially on a chemical and cellular basis. Even dedicated Bokashi groups on Facebook don’t understand what actually happens during the process.
I have been looking at some other forms of fermentation including ensilaging and eco-enzymes, and the picture of what they are is starting to become clearer.
What is Bokashi?
I have discussed bokashi in more detail in Bokashi vs Composting so I will just summarize the process here. Take a pail with a tight fitting lid and add chopped up food scraps. Add some bokashi bran, press it down to expel the air and cover it. This is an anaerobic process that ferments the kitchen scraps in a few weeks. It is then allowed to sit for a month to stabilize.
It is called bokashi composting, but there is virtually no composting in the bokashi process. All of the composting happens after the bokashi ferment is added to soil.
A key ingredient is the bokashi bran. It consists of bran, usually wheat or rice, molasses and EM inoculant. The bran is just a carrier for the other two items – it is not essential to the process. The molasses adds sugar for the microbes to eat, allowing them to multiply.
The EM inoculant contains a number of microbes, depending on the source, but these seem to be the main players.
- Lactic acid bacteria (LAB)
- Photosynthetic bacteria
- Yeasts
- Actinomycetes
- Fermenting Fungi
Out of this group, it is the lactic acid bacteria (LAB) that are responsible for the majority of the fermentation process. LAB is a group of several genera including Lactobacillus, Leuconostoc, Pediococcus, Lactococcus, and Streptococcus. A number of studies have suggested that this is the only set of microbes that are required for bokashi and that the others in EM are not needed.
Bokashi is a fermentation process that preserves organic scraps, it does not decompose them.
What is Ensilaging?
Ensilaging is a process used to preserve feed stocks like maize, grasses, legumes, wheat and lucerne, and has been used for 4,000 years.
The feed stock is harvested, cut into small pieces, added to some kind of vessel, compacted and allowed to ferment. Once the material is fermented, it is stable and can be kept for some time until it is required to feed animals. The process is a way of preserving animal feed until it is needed.
This process has been studied much better than bokashi. The initial material is aerobic but the amount of oxygen is quite small because of the compaction. Existing microbes on the feed material start to decompose the material and convert oxygen and sugars into organic acids and CO2. Within a few hours, the environment becomes anaerobic and acidic. This stops most microbes from growing and even kills some off, while the the lactic acid bacteria thrive and continue the process of producing more acids. After several days or a few weeks, depending on the material, the acidity drops so low that even LAB stop functioning. The silage produced is now stable and provided oxygen is kept out, it will remain stable for quite some time.
Note that this process happens without the addition of microbes. The microbes responsible for the fermentation are natural ones that coat all of the material anyway.
In recent years, agriculture has started fine tuning this process and they have started adding things to ensure proper fermentation takes place. Too much growth of aerobic bacteria and yeasts in the early stages can make the feed less suitable for animals. Proteins start to degrade quickly as soon as the material is harvested. Some common additives include LAB, molasses (2 to 5 % of fresh silage weight) and organic acids (propionic and formic).
The effectiveness of applied LAB inoculant depends on the natural lactic acid bacterial population, the sugar content of the crop, and strains of other bacteria in the inoculant. The inoculant must provide at least a tenfold increase in the quantity of lactic acid bacteria to be economically practical.
What is Eco-enzyme
Eco-enzyme is a process of fermenting kitchen scraps. You take some water, sugar or molasses, add chopped kitchen scraps, and place everything in a sealed container. The water and container ensure that the process takes place anaerobically. The fermentation is carried out by the natural microbes already on the kitchen scraps. It produces several organic acids including lactic and acetic, which lowers the pH. The anaerobic conditions prevent pathogens from growing.
This process is called eco-enzyme because the microbes produce a number of enzymes and it is these enzymes that are given credit for some of its benefits.
At the end of the process, the liquid is filtered off from the ferment and is used for feeding plants and as a cleaning agent. The ferment is used just like bokashi ferment and is either composted or added directly to soil.
Comparing Fermentation Processes
Bokashi, ensilaging and eco-enzyme are all fermentation processes used by both homeowners and farmers. They each take organic matter and ferment it into a stable ferment. Each is done anaerobically and LAB are the major microbes responsible for the process.
The key to making them work is to have LAB present at the start of the process. In bokashi, LAB is added, but in the other two methods they are not. This begs the question, do you really need to add them for bokashi? Some limited research indicates EM does not need to be added. A number of procedures that are hybrids of the bokashi described above and ensilaging are used in agricultural settings. These farmers do not add expensive EM mixtures and some homeowners do bokashi using DIY collected microbes. It seems as if EM is not a requirement for bokashi.
It is critical that some form of sugar is available for LAB to convert into lactic acid. Readily available sugar ensures that the pH drops before other organisms can become dominant in the mixture.
What Happens During the Bokashi Process?
Bokashi is very much like ensilaging and probably follows the same biochemical process. Sugars are converted to acids dropping the pH, which stops further decomposition of the input material. Bokashi is a way to preserve kitchen scraps and prevent most of the decomposition.
Bokashi ferment can be fed to worms in vermicomposting, but I don’t see the point of that since the original food scraps can be fed to the worms directly.
Why would a homeowner want to preserve kitchen scraps? Some have suggested that it is a way of handling them in winter when you don’t want to go outside. Fair enough, but it is much easier to have a pail in the garage and dump them there until spring.
The concept of using bokashi in a soil factory is used by some to improve potting soil. There are no real studies to show how well this works, or how quickly the material decomposes. The ferment does disappear and we can assume nutrients are eventually added to soil. You can also use a blender to turn your kitchen scraps into a slurry and add that to soil. There seems to be little reason to preserve the scraps using bokashi and then add them to soil.
Thanks for the informative article. Based on the other comments, it seems that many of us arrived at this article while trying to answer roughly the same question.
Some of us face restrictions and either cannot or would greatly benefit from not putting compost-blacklisted waste in the trash. Bokashi fermentation purports to render output material that is brittle in the case of bones and unattractive to animals – an apparent solution at the cost of additional work and complexity.
Question: what is the most practical way for us to despose and make use of our meat, bone, dairy, and bread scraps in the garden?
From reading your articles and watching your videos, I’m fairly convinced that the most practical, efficient, and ultimately garden-beneficial way to dispose of most kitchen scraps is through simple outdoor composting, which we do at our home, and I assume many of your readers do too.
So I ask you and your readers, given the aforementioned scenario, what would you do?
Thanks for your insights.
1) dairy and bread can be composted.
2) we never throw out meat – we eat it.
3) fat scraps and bones go in the garbage.
I have been experimenting and reading up on bokashi composting and came to the conclusion that it was the same as ensiling. I put both terms into a search engine and was referred to your article.
No one else makes that statement – but it is the conclusion I came to as well. Or at least they are very similar.
Thank you! This was a very interesting, thought provoking read. Now I have many questions. I have not yet begun to do bokashi but am considering it for a few reasons:
-My family of 10 has a lot of food preparation and leftover waste.
-I am not supposed to feed my vermicomposting system meats, bones, citrus, onions, dairy….and a lot of our waste is just that.
-Our current compost heap is extremely slow due to our dry and cold climate…only 77 frost-free days a year.
-I don’t want to attract pests to my compost by adding our food waste to it.
My plan was to bokashi our food waste and then feed it my worms. I don’t really have the energy to dig and bury lots of bokashi around my garden, especially since it is all heavily mulched and I would have to rake away the mulch first and probably disturb the ecosystems of the soil if I did that anyway.
Hmmm. Would bokashi combined with vermicomposting be good in my situation. Can you think of a different way to compost my meats/bones/dairy, especially during the cold months?
Have you read much about what happens to the proteins during bokashi or ensilaging? Curious to learn more.
This is truly a troubling article and you should do a lot more research. First, Bokashi isn’t composting, it is pre-composting. There’s a difference. Second, Bokashi doesn’t preserve the material, it ferments it. The definition of fermentation is as follows: the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat. Now, Bokashi, when it is composting, doesn’t reach high temperatures, which makes Bokashi Composting unique. Third, Bokashi pre-compost breaks down at a much more rapid pace compared to any other form of composting and there is no putrid smell. Furthermore, there’s studies that show that using Bokashi in soil increases overall soil health with longer lasting nitrogen levels that are available to the plants. The bacteria from the Bokashi also keeps the soil healthy after harvest and will even start to break down hard soil and/or clay. The premise of this article is hugely flawed, especially since you think it is unnecessary. There’s a reason why this method has been used over the centuries in farming, and why Asian farms are starting to fair better than ours. It’s because of this style of farming. And, here is an extremely recent research paper done. I suggest you read it all the way through instead of cherry picking. Give out proper information, not biased information.
https://projects.sare.org/project-reports/gne15-098/
1) I never said it was compost – that is what others say.
2) Fermentation is a way of preservation – think sauerkraut.
3) “chemical breakdown of a substance by bacteria, yeasts, or other microorganisms,” that is not the definition of fermentation. If it were you would not end up with sauerkraut.
4) “Bokashi pre-compost breaks down at a much more rapid pace” – prove that to me with a scientific study.
The argument that I saw was, “bokashi can handle meat and dairy products. In most traditional compost methods, it’s common to try not to compost meat as it can be very smelly and may attract pests or predators to your compost bin.” (Source: https://www.epicgardening.com/bokashi-composting/) After this, you can take the meat and add it to your true/vermi compost and not have these issues.
My take is that this advice follows from a reaction to the scientific research showing that the tea was unhealthy and that the solid materials are not yet ready to be mixed into the garden. It proposes a practical use that is not yet dispelled/confirmed by the science.
To me, the idea sounds reasonable in terms of the smell component – pickled products smell like pickles, without much variation – but I’d wonder if worms really like pickled meat? I’d be worried that they would avoid it. Likewise, if we’ve added a preservative to the organic matter then I would worry that it won’t break down during heat composting as easily. And do larger animals like foxes and raccoons avoid pickled meats more than raw and rotting?
I feel like there’s some science that could be done on the question.
worms seem to dislike pickled material, but can be trained to eat it.
This is very interesting with lots of food for thought.
I’ve just begun researching microprocessing myself. (how to transform fish solids into plant food without removal from the system). Whether it be yeast, or some form of enzymes, or perhaps a nitrogen supplement. Thanks a bunch for this!