bokashi process

  1. Food Waste Drop-Off.
  2. Treating Food Waste with Bokashi.
    1. a. Labeling Bear Bins — Index Cards.
      b. Tracking Bear Bins — Log Sheets.
      c. Key Maps for Down to Earth Garden & El Sol Brillante.
    2. Fermenting Food Waste.
  3. Using Fermented Food Waste (FFW).
    1. Trenching/Burying.
    2. Vermicomposting – Worm Composing – Feeding FFW to Worms.
    3. Sandwiching FFW Between Soil in Pots/Planters.

1. Food Waste Drop-Off

Food waste can be dropped off at the garden during open hours or whenever the garden is open.

  • Open Hours

    Updated July 21, 2022

    Tuesdays 1:30 pm – 4 pm
    Sundays 10 am – 1 pm


2. Treating Food Waste with bokashi

Treating dropped-off food waste, 9/12/2016. This video (most of it sped up) shows the process when we had a 24-hour drop-off setup, and therefore you see the gray bin filled with bags of food waste. Today, post-pandemic, drop-offs can only be done when the garden is open, but the process in the bear bin is the same (adding food waste, sprinkling bokashi, and chopping).

Volunteers and garden members then take the dropped-off food waste and treats them with the bokashi sprinkle (a fermentation starter, which we make in the garden with wheat bran, water, blackstrap molasses, and EM-1 microbial inoculant).

The food waste is added to a bear bin (bear-proof storage bin, a 20-gallon screw-top airtight container) while the bokashi is sprinkled. The amount of bokashi added is sprinkled to sort of visually dust-cover the food waste. Ideally, for every 33 lbs of food waste, 1 lb of bokashi should be mixed in.

An ice chopper, or a square shovel, is used to cut the food waste into small pieces and mix with the bokashi while compressing them down to squeeze out as much air as possible. An airtight (anaerobic) condition is necessary for the fermentation to be successful. This also makes more room to add more food waste.

A 20-gallon bear bin may take 3 to 7 days to fill depending on the amount of dropped-off food waste coming in. A full bear bin will weigh on average about 150 lbs (about 145 of food waste and bokashi mix, and roughly 5 lbs the weight of the container and lid).

December 3, 2017

Shredding Food Waste

From 6/23/2018 until 2/3/2022, we had the option to shred the food waste, instead of chopping the food waste with the ice chopper or square shovel: see information, photos, and videos of our Mini Shredder.

The shredder broke down on 2/3/2022 due to deterioration of its ball bearings: see Loss of ball bearings, photos.


2.1.a. Labeling Bear Bins — Index Cards

In order to keep track of how much food waste we deal with, we use the following labeling and tracking method.

Labels are pre-printed on 4″x6″ index cards:

Front side
Back of the index card

FFWindexcardBatchLabel-2022-03.pdf (PDF version to print the label onto index cards)

Instructions to print onto index cards (Printing settings):

Printing settings

6” x 4” index cards  
(70 cards for DEG; 25 for ESB: total 95 cards — 95÷9=11 stacks of 9 index cards [printer being used can only do 9 index cards at a time]) 

PAGES
Page Setup … : “4 x 6”

PDF file.
Print …
- Copies: 9
- Uncheck “Two-Sided” (print one side first; 9 cards at a time)
- From: 1 to 1 (reverse 2 to 2)
- Paper Size: 4 x 6
- Preview: “Fill Entire Paper”
 -> Paper Handling:
	a. Check “Scale to fit paper size”
	b. Destination: 4 x 6

If printing afterwards goes incorrectly, then redo a and b above with each printing.

Reverse: face down, top is left.
—
If Presets: indexcard4x6
- From: 1 to 1 (reverse 2 to 2)
- “Fill Entire Paper”

—
3/31/17, number of index cards used per garden (24-hour drop-off): 
70 for CG/DEG. 
25 for ESB. 

2.1.b. Tracking Batches — Log Sheets

Terminology: batch = fermenting batch of food waste in a bokashi bin
bokashi bin = airtight container/bin to ferment food waste
bear bin = the type of bokashi bin used at Down to Earth Garden and El Sol Brillante

The log sheets keep track of batches, the next batch ready to trench/bury or feed to a worm compost bin, and where they are used (see Key Maps below). The log sheets also prevent and help to fix index cards with mistakes in numbering batches and bins, as well as, the dates (started, full, and ready dates).

Example Tracking Sheet – Bokashi Bin Log Sheet

Example bokashi bin log sheet, partly filled in.

Blank bokashi bin log sheets for printout:

For Down to Earth Garden (DEG):

For El Sol Brillante (ESB):


2.1.c. Key Maps for Down to Earth Garden & El Sol Brillante

Key Maps – garden grid map for locating where FFW was used/trenched:

To print – Down to Earth Garden: Used-Location-Key-Map-DEG-20220222.pdf

To print – El Sol Brillante: Used-Location-Key-Map-ESB-20220222.pdf


2.2. Fermenting Food Waste

Once the bear bin is full, it is very tightly closed and let to ferment in the garden for at least 2 weeks during warm weather, (April-September) and 1 month during colder weather (October-March).

The index card label is placed in a quart size ziplock bag, which is inserted in a gallon size ziplock bag which is attached to the lid of the bear bin.

To protect the ziplock labels from the elements*, a green lid is placed on top of the bear bin’s screw-top lid and weighed down with either small logs (or cut medium sized thick branches) or with a stone or brick. The weight prevents the green lid from being wind blown off.

* In the past, the ziplock labels were attached to the side of the bear bins. Over time, they deteriorated due to the elements (rain, snow, wind, dust, etc.), but also, some of the ziplock bags were bitten through or taken by rats (as bedding material?) — photos below.

The full bear bins should be moved throughout the garden in order to prevent congestion/blocking near the entrance where the drop-offs are treated and to make the garden look more organized/orderly. The bear bins can either be moved by rolling them on its bottom edge (at a 45° angle), but very slowly since they are very heavy (~150 lbs), or they can be move with the hand truck that is in the shed.


3. Using Fermented Food Waste (FFW)

There are different ways in which to use the fermented food waste (FFW). Below are three of the many ways to use and convert the FFW into either a soil amendment or compost.

3.1. Trenching/Burying FFW
3.2. Vermicomposting – Worm Composting – Feeding FFW to Worms
3.3. Sandwiching FFW Between Soil in Pots/Planters


3.1. Trenching/Burying FFW

The easiest way to use FFW is by burying it in soil (ground or garden bed) either in a trench or in pockets.

If burying in the ground, where we don’t really want to grow plants, it may take one to three months (depending on conditions and time of season) for over 90% of the FFW will disappear and become part of the soil. At which point, the soil can be harvested as amended soil and used in garden beds, tree pits, and landscaped soil areas.

If burying in a garden bed, wait two weeks after burying before planting seedlings or seeds. There are certain plants that can be planted the same day when the FFW is buried (such as okra seedlings). Other plants (Swiss chard and other similar leafy plants) will not do well until the FFW has had enough time to break down in the soil, usually two weeks after burying the FFW.

When burying FFW:

  1. Keep at least 1 foot away from existing plants, and at least 3 feet away from shrubs and trees.
  2. Dig a trench (long narrow 1-foot wide or large width) or hole(s) in a spot, a few spots, or throughout the ground or garden bed.
    1. Either dig deep enough, 1 to 2 feet deep, or for shallow digs the distance between the buried FFW and surface should be at least 8 inches or more.
      • The FFW can be done right on the surface (especially if the soil is too hard to dig or there’s too many rocks to dig through, or there’s a hardware fabric being used in the soil) as long as there’s at least 8 inches or more of soil completely covering the FFW.
      • With surface trenching, use soil to make a bowl to contain the FFW (see Bowl-burying FFW photos below).
    2. Specifically for small holes, using a hand trowel, you can make any size hole, but as an example, say 5-inch wide and 6 to 9 inches deep, add only about 1/2-cup to 1 cup of FFW, mix with some soil and optionally a handful of plant matter, then fill with plain soil, and cover on top with mulch, leaves and/or other plant matter (see 8 below).
      • This will feed nearby plants.
      • This can be done throughout the garden bed or garden area.
  3. Before covering the FFW with plain soil, it is best to break up any clumping or large pieces.
  4. Mix into the FFW any plant matter you may have on hand to help fluff the FFW since it can be very dense (which may then take longer for it to break down in the soil), especially if putting in more than 2 lbs of FFW per square foot. Use either a shovel or ice chopper to mix the plant matter with the FFW.
    • Plant matter can include leaves, clippings (browns or greens), twigs, branches cut into small pieces (thick branches, 1-inch or thicker, into a few inches; thin branches, less than 1-inch thick, into less than a foot long).
  5. Some soil, or soil-compost mix, can also be added onto the FFW and mixed in using a shovel or ice chopper. The amount of soil to mix in is about an amount that would very lightly cover the FFW. Also, use soil with unbroken down FFW bits from a recent trenching/burying (see 7 below).
  6. When covering the FFW + plant matter mix,
    • first, make sure that there are no bits of FFW outside the trench or hole, because over the next few days, those bits exposed to the air can cause a foul odor.
    • second, make sure to use either plain soil or a soil-compost mix to completely cover the FFW mix at least 8 inches or more. In other words, make sure there aren’t any FFW bits or if burying in a spot where FFW had been recently buried and there are still unbroken down bits still in the dug-up soil, place those parts in the trench/hole first.
  7. If burying in a spot where FFW was recently buried, either avoid the area until enough time has lapsed (1 to 3 months), or when digging up the soil, there are still bits of unbroken down FFW, then make sure that part of the dug-up soil is placed separately from the plain soil. Use this soil with unbroken down bits first when mixing in some soil into the freshly added FFW and/or when covering the FFW mix with soil.
  8. After completely covering the FFW mix with soil, cover the soil with a mulch or ground cover: use leaves, plant matter, twigs, whatever you may have on hand.
    • This will prevent or minimize evaporation of the soil. Moisture is critical for microbial activity which is what the bokashi method is all about (microbial activity, density, and diversity in the soil). Microbial activity means continual breakdown of plant matter and the FFW in the soil; microbes attracts and feeds other organisms (worms, insects).
    • The cover will mean less dusty conditions when no rainfall for awhile; and less muddy conditions when lots of rain.
    • The cover will also act as a blanket during the winter, keeping the ground from freezing over and keeping minimal life underneath even during the coldest part of winter (microbial and worm activity). See Ground soil temperature Jan. 15, 2022.
      • For this reason, we can trench in the garden throughout the winter.

Photos: trenching in the ground (where plants are not usually grown; walking area; pathways; outside of growing beds).

Cover the FFW-leaves-soil mix completely with plain soil

Photos: Bowl-trenching FFW (“surface trenching”)

The following were done by Earth Matter NY apprentices at the Soil Start Farm/Compost Learning Center on Governors Island, May 28, 2022. FFW (two 5-gallon buckets of FFW from Down to Earth Garden) were bowl-trenched in two separate bowl-trenches (photo galleries 1 and 2 below) in the middle row of 3 rows (1st row is the lasagna compost bed, which consists of multiple layers of cardboard, food scraps, and compost; the 2nd middle row is the bokashi bed, and the 3rd row is the soil-only bed, the control for this tomato growing experiment). Each row is segmented into 3 sections separated by the buckets of cement with metal posts. Below are bowl-trenching of 2 sections; the 1st section was bowl-trenched on April 9, 2022. Tomato seedlings of three different varieties were planted in each section. The tomato seedlings were planted on the same day the fresh FFW were bowl-trenched for the 2nd and 3rd section of the bokashi row (the 1st section had 7 weeks between bowl-trenching and planting).

Bowl-trench 1
Bowl-trench 2

3.2. Vermicomposting – Feeding FFW to Worms – Worm Compost

Our worm compost bin is just a typical wood frame with hardware cloth (wire mesh, chicken wire), each side 1 cubic yard (2 cubic yards total).

3.2.a. Feeding FFW to Worms
3.2.b. Checking the worm compost bin
3.2.c. Sifting the ready worm compost


3.2.a. Feeding FFW to Worms


3.2.b. Checking the worm compost bin


3.2.c. Sifting the ready worm compost


3.3. Sandwiching FFW Between Soil in Pots/Planters