Bokashi Composting Myths

Bokashi composting, also spelled bocashi composting, is a new way to deal with kitchen scraps. The proponents of the system claim that it has a number of benefits not found in more traditional composting methods. In this blog post, I will have a close look at Bokashi composting and separate myth from reality.

Bokashi Composting—What is it?

From Bokashicomposting.com we have the following description: “Bokashi composting is a safe, convenient, and quick way to compost food waste in your kitchen, garage, or apartment.”

To get started, you need a special bokashi bucket that has a tight lid and a spigot at the bottom to drain off liquids (pictured above). These will run you $60 to $150, or you can make a DIY for $20. You also need the ‘special sauce’! It would not be a very good process if there was no special sauce to sell you. It is normally referred to as bokashi bran or Effective Microbes.

The process is fairly simple. Put your food scraps in the pail and sprinkle some bokashi bran on top. Squish it down tight to get the air out. Close the lid. Each time you have more scraps, add them to the pail, add bran, and squish.

After a few days, liquid starts to form in the bottom of the pail. This needs to be drained, or it will start to stink. This liquid, the ‘bokashi tea,’ can be used to fertilize your house plants or your garden plants.

After a few weeks, when the pail is full, you take the contents outside and either dig it into your garden or add it to your compost pile.

That is the basic process. If you want more details or have specific questions about the process, there is lots of info on the net.

Benefits of Bokashi Composting

I found the following benefits listed at various sites on the net.

1)      You can compost dairy products and meat.

2)      No strong odors

3)      No nutrients lost

4)      No insects or rodents

5)      No turning necessary

6)      No need to worry about the amount of greens and browns

7)      Food scraps are inoculated with EM (Effective Microbes)

8)      Produces a nutrient-rich tea for plants

9)      Can be carried out on a small scale, which is perfect for apartments

10)   Very quick—complete in 2 weeks

11)   Saying the word ‘bokashi’ will impress friends. 🙂

This sounds like a good system, and any system that returns kitchen scraps to the soil is a good thing. So in general, I have no problem with bokashi composting. If it gets you composting—great.

But… there is always a but. Is this really a method of composting? Is this system better than the more traditional methods of composting? These are the important questions and the ones I will look at in the rest of this post.

Bokashi Composting—Is it Really Composting?

If you read the above quickly, you might have missed the statement that says, “After a few weeks, when the pail is full, you take the contents outside and either dig it into your garden or add it to your compost pile.” Does this make sense? Why would you add fully composted material back to the compost pile?

If you read the fine print, you soon understand that bokashi composting is not a composting process at all. Bokashi in Japanese means to ferment. This process is actually a fermentation process. What you are doing is turning your kitchen scraps into pickled kitchen scraps. At the end of the process, the food looks just like it did when it went into the system, except it’s pickled. An orange looks like an orange, and an apple looks like an apple.

There is no composting taking place in bokashi composting—talk about false advertising!

Knowing this fact makes the earlier statement make more sense. Once you have fermented your scraps, you then need to compost them. You can do this by adding them to a compost pile, or you can just dig them into your garden soil, where they will compost naturally.

This system is especially promoted for apartment owners—what do they do with it after fermentation? Throw it in the garbage? They could have done that before fermenting.

Now that you understand the process, it is also clear why it is so fast—only 2 weeks. It is fast because there is no composting, which is a slow process.

Bokashi composting is not composting!

Bokashi vs Traditional Composting

The benefits listed above as #2 to #6, inclusive, are really not benefits when we compare the two methods. I make compost in bins and don’t worry about greens and browns—I just add whatever I have. It is outside, so the smell does not bother me, and if a mouse comes by for a bite to eat, so what! Nutrients can be lost if it rains too much, but they are lost to the soil below the compost pile—they are not really lost since the tree roots under the compost pile use the nutrients. If I really care about nutrient loss, I can cover the compost pile to keep out the rain.

Traditional composting, if higher temperatures are reached, can even compost meat and cheese.

The difference in the two systems is the pickling process. The apparent benefits of pickling are the Effective Microbes added to soil and the bokashi tea.

For more information on traditional composting, see Compost—What is Compost? and Benefits of Composting.

For a detailed comparison of Bokashi and traditional composting see, Bokashi vs. Composting.

Effective Microbes

Dr. Higa, the person who originally developed the bokashi system, also developed a special sauce that he called ‘Effective Microbes’ (EM). All kinds of special properties have been assigned to this mixture, but nowadays lots of people sell the microbes already added to the bran. Everyone in the industry now has their own ‘secret sauce,’ i.e., Effective Microbes + bran.

Adding the microbes is important since they control the fermentation process. For example, in winemaking, special starter yeast mixtures may be added to start the process. The reason for doing this is that you want the right kind of microbes to grow quickly and outcompete the ones that will create a lot of bad odors.

There are also claims that the EM are good for the garden. There are some studies that show a benefit from the microbes, but most show no positive results.

Testing of EM tea on field-grown crops found that they did not increase yield. Similar field studies have shown the same results. Effective microbes are important to make the bokashi system work, but they don’t really add any benefit to your garden.

Note (added April 2021): More recent research indicates that even the EM microbes may not be required for making Bokashi.

Nutritious Bokashi Tea

As fermentation progresses, excess liquid drains into the bottom of the pail, and you need to remove it. It is claimed that this tea is a great source of nutrients for your plants.

How nutritious is it? Some sites say that you can use it straight or dilute it 1:100. That is a huge red flag. A fertilizer that can be effective at full strength and at a 100 dilution rate does not make sense. Some people have commented that “it’s a biology thing, not a chemistry thing, and so the dilution does not matter.” They are saying ignore the nutrients because it is the microbes that are important. I addressed that in the discussion above. The science does not support the idea that the microbes add value. Even if they did, dilution by a factor of 100 would still be important.

There is very little published about the nutrient levels in Bokashi tea, which is odd since so many websites promote it. I did find one study and analyzed it in another post called Is Bokashi Tea a Good Fertilizer?

In short, it contains very little nitrogen, high levels of P and K, and several of the micronutrients are on the low side. It also contains high levels of sodium and chloride, both of which are toxic to plants at low levels.

Bokashi tea should not be used on container plants, and even in the garden it should be diluted 1:100 before it is used to reduce any potential damage from sodium and chloride.

Real Benefits of Bokashi

I am still not sold on Bokashi. The tea has no real value, and the fermented food scraps still need to be disposed of. If you are going to dispose of them in the garden, you might as well compost instead.

In recent years a new way of handling the Bokashi ferment, called Soil Factory, has become popular. I have discussed it in detail in Soil Factory Using Bokashi Ferment. It is a way to process the scraps in the home in a few weeks. You can even use my improved Instant Soil Factory method and eliminate the two-week period. Using these methods, Bokashi makes sense for apartment owners and others with no garden.

Both bokashi composting and traditional composting provide your garden and plants with the same benefits. Bokashi just seems to be an additional extra step that is not necessary. I would not use it.

That leaves us with one benefit from the list presented above, and this one can’t be denied. Saying the word ‘bokashi’ is cool and will impress your friends.