The neighborhood started charging more tax for garbage (yay!)
and the compost small plastic bins in the summer would sit for too long and generate tons of flies and other creatures...and smelled very bad (boo!).
This was great motivation to try some worm composting.
- 1 What is Vermicomposting?
- 2 Prototype
- 3 Repeat of What not to Compost
- 4 Troubleshooting and Improvements
- 5 Links
What is Vermicomposting?
The Biology and Chemistry
Vermicomposting is a process that involves chemical, physical, and biological transformations of solid organic materials (agricultural residues of plant and animal origin) through the use of worms and microorganisms (Garg and Gupta, 2009).
Worm Anatomy as it relates to Composting
The Biology and Chemistry in a nutshell in this short video by PBS and American Chemical Society.
- Esophagus : Calcium Carbonate secretion to remove excess calcium from the body, and neutralize acidic food
- Gizzard : This is where the food is mashed physically by sand
- Intestines : This is where enzymatic and microbial processing of the ingested foodstuff gets digested
- mucus containing protein and polysaccharides
- digestive enzymes such as amylase, cellulase, protease, lipase, chitinase and urease
- organic and mineral matter
- amino acids
- It's not only worms - microbial symbionts (bacteria, protozoa and microfungi) - also responsible for some of the digestive enzymes)
- mucus containing protein and polysaccharides
- Anus : This is where the processed worm castings (waste, i.e. poop) comes out. One man's waste is another one's gold!
Some more details here in the Worm Biology
Worm reproduction is a wonderful thing - this will allow you to share the worms with other people.
For E. foetida reproduction, taken from Sierra worm compost
- Produce 3.8 cocoon per adult per week.
- Each cocoon contains between 8-20 eggs, but on average only 3.3 worms will actually hatch.
- Hatching occurs in about 3 weeks.
- 53-76 days to sexual maturity.
- 85-149 days from egg to maturity.
This video shows the reproductive process - worms are SIMULTANEOUS hermaphrodites, and sexual intercourse between two worms using both male and female reproductive organs will give rise to worm eggs (video).
Concept behind the Prototype
Worm composting can be done indoors in small apartments, as well as outdoors.
- Compost vegetable matter, even coffee rinds! - except egg shells - BUT no meat, no starch in your compost
- Good moisture
- Not in direct sunlight
- Good air circulation (turn it over)
- Balance the worm diet and balance YOUR diet! (too much citrus, coffee rinds will acidify, etc.)
There is a lot online on how to start one (links below) - this one aimed for these features:
- One person
- Balcony location
- No need to touch the worms
The design here assumes that the worms are smart enough to want to look for food i.e. that they are epigeics (the worms like surface soil), which will stay on the top of the composting bin.
Materials and Tools
- Plastic garbage bin
- Plastic receptacle
- Plastic receiving tray
- Metal chickenwire / mesh
- Metal support rods
- Cutter for plastic
- Cutter for Wires
- Drill (to make airholes)
- A ziptie for a handle
- Salad turners for "tossing the compost" for aeration
Can you dig up worms yourself in the garden and do this?
The answer is no, for this type of design. See above for the types of worms.
Otherwise, look for suppliers in the neighborhood.
Repeat of What not to Compost
What not to compost at home:
- Dairy products
- Oils, fats
- Pet waste (contains harmful pathogens - unless processed in heat compost)
- Sugars (attracts ants)
In effect, a good vegetarian mix + also, coffee, tea, plants, paper (cellulose).
Rotten food is welcome.
Onions, garlic or citrus (in small quantities), not too spicy also.
Chop them up for easy eating.
Feed them, and see how it goes.
Troubleshooting and Improvements
Using composting worms (Eisenia foetida), there are hardly any worms try to escape from the bottom. There was never a need to "separate" the worms from the compost, which most articles suggested to do. But here are some things to do differently than this version.
- Need a bigger bin!
- Make the "bottom window" to take out the compost a bit higher off the ground, to catch the brown water, especially for indoor composting.
NICE TROUBLESHOOTING TABLE HERE by Sierra Worm Compost.
- DIY indoor vermicomposting
- Quick Facts about worm composting
- 3-tier system
- preventing fruit flies! very useful tips toward the end of the article
- Troubleshooting your Compost
- Worm anatomy diagrams
- Sierra worm compost website - great summary including more scientific things
- NA SENIOR HIGH SCHOOL Earth Worm Dissection
- How Stuff Works, Earth Worm
Nicely Designed Worm Compost Bins
- wormup makes them in sustainable ceramic!