Features and Occasionals

Bokashi Composting

By Margaret Park

About five years ago I read about bokashi on the internet and started using the bokashi composting method to improve the soil in my vegetable garden. Bokashi is a mixture of active microorganisms fermented in a medium of rice or wheat bran that is added to plant materials to accelerate their decomposition. I now attribute much of my gardening success to this easy and inexpensive way of composting. The process helped transform the dry, dead dirt in my garden into fertile, living soil in only one year.

To try this composting method, all you need are the bokashi accelerant, which you can make at home using bran and a proprietary blend of microorganisms called EM-1®; two buckets with tight-fitting lids—an actively collecting bucket in your kitchen and a fermenting bucket outdoors; and whatever plant peels, stems, leaves, even yard waste you wish to dispose of as valuable fertilizer for your soil. There’s no need for piles, bins, drums or other equipment to take up outdoor space that could otherwise be used for growing plants.

There’s no need for turning the materials, either. When the waste materials in the bucket are fermented (in about two to six weeks, depending on the temperature) the bucket contents are buried in the soil for further decomposition. The micro­organisms then devour minerals in the soil and convert them into more bio-available forms the plants can consume. Worms love bokashi compost, too, and happily populate the bokashi-treated soil.

The proprietory combination of microorganisms known as EM-1 was discovered in 1982 by Teruo Higa, Ph.D. (Agricultural Research), professor at Ryukyus University in Okinawa. “EM” stands for “effective microorganisms.” Higa’s formula is a combined culture of aerobic and anaerobic microbes that co-exist symbiotically.

Research on EM-1 cultures has shown that these microorganisms can suppress soil-borne pathogens, accelerate the decomposition of organic wastes, increase the availability of mineral nutrients and useful organic compounds to plants, enhance the activities of beneficial micro­organisms (e.g., mycorrhizae and nitrogen-fixing bacteria) and reduce the need for chemical fertilizers and pesticides. EM-1 is safe for humans, animals and the environment. It increases beneficial soil microorganisms and suppresses harmful ones.

You can buy ready-made bokashi that you can sprinkle onto the waste in your kitchen bucket. (Available online. Sometimes you can get it locally at Spiral Connections, formerly known as Cosmic Spiral, in Holladay.) Or you can make your own.

How to make your own bokashi

Making bokashi is a two-step process. First, you will have to activate the EM-1® microbes and bring the brew to a pH of 4.0 or lower. Second, you mix the activated low pH brew with bran and a few other things. The bokashi will be ready in two to four weeks. However, the Activated EM brew will last for many months at room temperature and can be used to prepare future batches of bokashi.

Step One: Activate the effective microrganisms

You will need:

EM-1® (buy online at www.teraganix.com and other websites)

pH strips (capable of measuring low pH’s like 4.0)

Lidded jar that can hold 3 cups

Unsulfured molasses

Non-chlorinated water (or chlorinated tap water that has been left to stand for a day)


1. Gather the ingredients.

2. Sterilize the jar by washing it and immersing it in boiling water.

3. Cool the jar and add 2½ cups of warm non-chlorinated water.

4. Add 2 Tbs. of unsulfured molasses.

5. Add 2 Tbs. of EM-1®

6. Stir.

7. Cover the jar with the lid (this is an anaerobic process) and keep it in a warm place. The warmer the location, the faster the organisms multiply. After about a week, test the brew with pH paper every few days. When the pH drops to 4.0, the Activated EM is ready.

Step Two: Making the bokashi

You will need:

Activated EM

Wheat or rice bran (wheat bran is cheaper and can be bought in small quantities in stores that carry bulk foods. Large quantities of rice and wheat bran can be found at farm supply or animal feed stores)

Unsulfured molasses

Non-chlorinated water

A mixing container that can hold 3½ lbs. of bran (a kitchen sink-sized wash basin works well)

A clean plastic bag (5-gallon capacity is more than enough) with a twist tie


1. Sterilize the mixing container (you can wipe it down with bleach and then rinse it well).

2. Add 3½ lbs. of bran.

3. Place 2 cups of water in a clean jar or bowl, then discard 2 Tbs of the water.

4. Add 2 tsp of molasses to water.

5. Add 2 tsp of Activated EM to water.

6. Stir or shake to blend well.

7. Combine wet and dry ingredients; mix until the bran is consistently moist.

8. Transfer to a clean plastic bag and close with a twist tie

9. Keep in a warm place

Bokashi may take from three days (if ambient temperature is 97 degrees F) to over two weeks (72-80 degree range.) When the bokashi is done it should have a clean, sweet and sour smell. If it’s doing really well, you’ll see whitish fungal threads throughout (this is mycorrhizae). If your batch has grown some fuzzy, bad smelling molds, it means something has gone wrong in the process and the batch should be discarded.

If temperatures are cooler, you can raise the temperature by putting your jar of Activated EM or bag of bokashi in a box with a 15-watt light bulb (not CFL). Make sure the light bulb won’t come into contact with a material that can catch fire easily.

How to use bokashi to make compost

For your kitchen compost bucket, choose a container with a tight-fitting lid. Sprinkle a bit of bokashi into your kitchen compost bucket every day or so. When the bucket is full, it can be moved outdoors until it’s ready to be buried. It’s nice if the buckets—especially the outdoor bucket—has a spigot at the base to drain accumulated liquids. Keeping the bucket drained will keep odors at bay. The liquid will be loaded with friendly microbes and can be beneficially poured down drains to help keep them clean, or poured on top of the garden soil. It’s possible to buy buckets that are already tapped with spigots — a more expensive proposition — and it’s also possible to buy a spigot and install it yourself. Beer-making supply stores carry suitable spigots. However, this is more a nicety than a necessity.

Bokashi works with yard waste, too, especially if you have a small yard like mine. In the fall, I put leaves and extra garden waste into clean plastic garbage bags and add bokashi to them. Vermin don’t seem to be too interested in bags of decaying leaves and tomato vines, so the bags remain unmolested. I place these bags of composting leaves on top of root vegetables in late fall to keep the plants warmer for later harvest. Sometimes these plants over-winter under the bags of decomposing leaves.

Using the compost

If you’re accustomed to compost looking like the stuff that comes in bags from the garden store—dark, loose, lightweight soil—the sight of bokashi compost will not impress you. It more resembles exactly what it is—rotting plant material. But you won’t have to look at it long because the next step is to bury it:

In the garden, dig a shovel-wide trench to a depth of five or six inches. Add an inch or two of bokashi compost and work it into the soil at the bottom of the trench. You can plant seeds or seedlings in the composted area after two weeks or so. Once the compost is underground, the decomposition process speeds up, especially in warm weather.

You can also work the bokashi into the soil around established plants.

If you’ve made more than you can use in a few months, share it with a friend, or dry it by spreading it on a tarp. However, moist bokashi works better. The one time I dried it, it didn’t have as much capacity to control odors. 

This article was originally published on August 30, 2013.