Make Bokashi Yourself – This Is How It Works

Last updated on October 23rd, 2023 at 08:28 pm

Bokashi, the Japanese way of composting, has seen a resurgence in recent years. Find out what it’s all about, how bokashi differs from compost and why a bokashi bucket is indispensable here.

Turn your daily kitchen waste into valuable fertilizer for your garden and balcony? This can be realized even on a small area – thanks to Bokashi! What the method is all about and how you can make your own fertilizer in a bokashi bucket – here comes a step-by-step guide:

What is Bokashi?

Bokashi comes from Japanese and means something like “fermented organic material”. It is used like compost, but is much less labor intensive to produce and does not smell. With Bokashi, organic material (garden or kitchen waste) is shredded, inoculated with so-called Effective Microorganisms (EM) and fermented in an airtight container. Within two to six weeks, valuable liquid fertilizer for plants is produced. In addition, the process produces fermented plant residue that can be worked flat into the soil or composted.

The advantages of this kitchen composter are that it saves space and time and is much less work than a conventional compost heap. Due to its low odor, a Bokashi bucket can also be lived with in the kitchen. What’s more, the daily kitchen waste is directly “recycled” and transformed into high-quality bio-fertilizer.

Fermentation and Effective Microorganisms (EM)

Fermentation (also called lactic acid fermentation) is basically fermented organic material by lactic acid bacteria. During fermentation, these lactic acid bacteria feed on carbohydrates from the organic waste. This metabolism enriches the original material with additional valuable vitamins, enzymes, acids and minerals.

Although fermentation is more familiar to us from food preservation (yogurt, cheese, sauerkraut, beer, wine, etc.), other organic materials such as garden or kitchen waste can also be fermented and thus enriched with valuable ingredients. The spiritual father of Bokashi, Teruo Higa, a Japanese professor of horticulture, developed the described method about 40 years ago. Shortly afterwards, he succeeded in scientifically proving the immediate improvement of soil quality through natural microorganisms. Bokashi was born.

Higa experimented with different microorganisms until he was able to record a special mixture of lactic acid bacteria, yeasts and photosynthetic bacteria as particularly profitable. He called them Effective Microorganisms (EM). In Bokashi, the Effective Microorganisms not only help to process organic waste, but also to produce a fully ecological fertilizer from it.

Difference between Bokashi and compost

Both bokashi and compost have soil-improving properties and are nutrient-rich – but the way they get there differs immensely. Composting involves piling organic scraps and organic waste on top of each other, which decompose when exposed to heat, oxygen and water. Although various micro- and macro-organisms are involved in this process, similar to Bokashi, the process is different: compost is created because organic waste rots and transforms into humus-rich soil over time. In this process, a regular supply of oxygen and heat are important success factors for maturation. Bokashi, on the other hand, matures anaerobically, i.e. in the absence of air, and at very low temperatures.

Another important difference between the two methods lies in the end result: compost ultimately produces crumbly, humus-rich soil that is converted into nutrients by soil organisms in the garden and is available to the plants. Bokashi forms two products through fermentation: a juice that can be used as a liquid fertilizer and the Bokashi Ferment, a pre-digested food for soil organisms that has not yet been digested. The finished Bokashi Ferment contains all the nutrients of the original organic material and, thanks to Effective Microorganisms (EM), additional nutrients as well. It is mixed with soil in the garden and decomposes into humus-rich soil within four to six weeks; the nutrients are released directly into the soil as it decomposes.

The time required also differs between the two methods. Fermentation is much faster (about 2-4 weeks) than composting and is directly available as fertilizer.

The Bokashi Bucket – Info and Tips

What is a Bokashi bucket?

To make valuable fertilizer from kitchen waste, a so-called Bokashi bucket is a good idea: In this airtight plastic bucket with sieve insert you fill your organic waste and spray or mix it with Effective Microorganisms (EM). To ensure that the organic material ferments quickly, the garden and kitchen waste must be shredded beforehand. The leachate produced during fermentation can be drained through a spigot and used as liquid fertilizer.

What can be put into a Bokashi bucket – and what not?

All common garden and kitchen waste such as plant residues, lawn clippings, fruit and vegetable scraps, and coffee grounds are suitable for bokashi. Large bones, ashes, meat, fish or paper should be avoided, as well as pasta or potato dishes, fats and oils, as they inhibit the work of microorganisms or are poorly broken down.

Build your own Bokashi bucket

Special Bokashi buckets can be bought in specialized shops – but you can also easily build them yourself. For this you need a plastic container with a lid and a capacity of 15 to 20 liters, a sieve insert and a small outlet tap: Drill a hole 2 to 5 cm above the bottom for the outlet tap and place it inside. Then attach the strainer insert above the outlet tap.

Making fertilizer in the Bokashi bucket – this is how it works.
For Bokashi, you only need a handful of utensils to get started:

• a Bokashi bucket
• a solution with Effective Microorganisms (EM)
• a spray bottle that you can use to spread the EM solution on the organic material
• a plastic bag with zip closure, filled with sand or water
• optional: rock flour (helps to make the nutrients of the Bokashi ferment available to the soil)

Tip: If you have a large amount of kitchen waste, two bokashi buckets are useful. This way, one can ferment in peace while the other is filled daily with kitchen waste.

Similar to composting, the organic waste from the garden and kitchen is well chopped up and layered in the Bokashi bucket. During this process, each layer should be sprayed with the EM mixture and compacted by tamping to keep the material moist and airtight.

Then place the plastic bag filled with sand or water on top so that the entire surface is covered.
After that, close the bokashi bucket tightly again each time to prevent oxygen from reaching the ferment.
Repeat this process until the bokashi bucket is well filled with waste and then allow it to ferment for about 2 more weeks before the finished ferment can be incorporated into the soil. The ferment is ready when it smells sour (slightly like apple cider vinegar) in the bucket. The leachate that is produced during fermentation can be drained through the drainage tap every two to three days.

Tip: Bokashi should always be slightly moist, the finished ferment crumbly and loose.

Bokashi: use the juice and ferment properly.

The leachate they regularly drain from the bucket is very rich in nutrients (nitrogen, potassium, magnesium) and is perfect as lawn fertilizer, plant slurry or for trees. You can also use it as a compost accelerator. Bokashi juice should be used quickly, as it quickly begins to mold. It has a low pH, so it should be applied with water at a mixing ratio of 1:100 and 1:200 for young plants. To use the juice as a pesticide against aphids, 40 ml to 500 ml of water is enough.

You can mix the mature Bokashi ferment from the bucket directly with soil – one bucket of ferment is enough for about 100 liters of soil. After mixing, the Bokashi Ferment should rest for about a week and only then come into contact with plants. Otherwise, the low pH of the Bokashi could damage fine roots. During the frost-free period, the Bokashi can be buried in planting beds or small trenches (about 10 cm deep) between plants and covered with soil.

Storing Bokashi in winter

During the cold season, there is often a lack of uses for Bokashi, so it makes sense to store the ferment until spring. You can use bags or plastic garbage cans for this purpose: Take the ferment out of the kitchen composter, put it into the bags and squeeze out excess oxygen. Then store them in a frost-free, cool place out of direct sunlight. This will keep the bokashi ferment fresh for a long time and can be collected for the next gardening season.