DIY Flow-Through Composter: How to Build a Coffee Can Worm Composter - Dengarden - Home and Garden
Updated date:

DIY Flow-Through Composter: How to Build a Coffee Can Worm Composter

Author:

Jocelyn writes about homesteading and organic living. Many of her ideas can be put to use on small plots of land.

My stacked, flow-through, worm composter made with three plastic coffee cans.

My stacked, flow-through, worm composter made with three plastic coffee cans.

How to Make Your Own Worm Composter

Using a few plastic coffee containers and a few common tools, you can make your own stacked, flow-through, worm composter that you can use indoors. My homemade composter was able to make 15 gallons of worm tea!

Tools You Will Need:

  • 3 plastic coffee cans with lids
  • Cardboard
  • Drill
  • A small drill bit (a 1/4" bit will do)
  • 8 one-inch wooden or plastic dowel pieces
  • Stones (to hold down the leachate collector)
  • Nontoxic moss
  • Worm food
  • Composting worms (I use red wigglers)

Step-by-Step Instructions for DIY Worm Composter With Pictures

Below is a step-by-step guide for making your own worm composter at home. I also included pictures for reference.

1. Drill Holes in One Coffee Can Lid

I drilled a hole in the center of the lid and then six more around it in a hexagon pattern.

I drilled a hole in the center of the lid and then six more around it in a hexagon pattern.

2. Drill Several Holes in Two of the Coffee Cans.

The holes don't have to make a symmetrical pattern, but you want a few around the perimeter for the next step.

The holes don't have to make a symmetrical pattern, but you want a few around the perimeter for the next step.

  • The holes don't have to be in a symmetrical pattern, but you want enough to allow for drainage.
  • Make sure to have a few holes near the edges so that you can insert the dowels to allow for stacking.

3. Insert the Dowels in the Holes Around the Edge

The dowels keep the cans from sliding off each other.

The dowels keep the cans from sliding off each other.

  • Push the dowels snugly into the holes so they catch the sides of the can they are stacked on.
  • I am using plastic screw anchors because I didn't have dowels handy.

4. Layer One Drilled Coffee Can With Worm Bedding

Moss balls are great for composting worms.

Moss balls are great for composting worms.

What I Use to Make Compost Worm Bedding

  • Brown leaves
  • Moss
  • Soil
  • Cardboard pieces

A sprinkle of healthy soil gives the worms food and helps jumpstart the composting process.

Moss balls are the preferred habitat for egg laying. Mine were literally speckled with eggs less than a week after I placed the worms in the container. They love moss and can be found in the balls every time I turn the bin.

Moss balls also retain a good amount of moisture without getting sodden. If you're afraid of disease and pests, try boiling the moss for several minutes before adding it to the container.

5. Stack the Coffee Cans

  • Set the filled coffee can in the center of the three cans. This is where the worms go.
  • When the center can has composted, start adding bedding and food to the top can. The worms will go through the holes in the top can and into the fresh bedding/food.

6. Remove the Moss Balls From the Center Bin

Red wiggler worm eggs in moss balls.

Red wiggler worm eggs in moss balls.

  • Remove the moss balls from the finished compost. They contain lots of eggs.
  • Place them in the new compost in the top bin.

Note the eggs in the moss ball above. There are several eggs attached to the moss. They cling firmly, and the entire moss ball can be removed and placed in fresh litter. My worms lay most of their eggs in the moss, not in the bedding or the food.

7. Make Use of the Worm Castings!

Worm castings!

Worm castings!

  • Sift the center (finished) can to remove leftover worms and stray egg casings.
  • Use the castings (poop) to make worm tea or add them directly to your garden or flowerpots.
  • Happy worms make lots of poop. These castings are just right for houseplants, aquarium plants, and garden vegetables and fruits.
Red wiggler leachate collected from my DIY flow-through composter. I use this on my houseplants.

Red wiggler leachate collected from my DIY flow-through composter. I use this on my houseplants.

How to Harvest Worm Castings From Compost

Harvesting the worm castings is easy.

  1. Place the compost container in a large bucket, and pour rainwater through it.
  2. Do this until it starts to run pretty clear but not too clear. You want to get all the poo you can without diluting the tea.
  3. Run that liquid through a sieve to collect any worms or eggs that passed through.

This makes a great start to perfect worm tea, with the added bonus of not having to pick the worms and eggs out! The worms in this DIY composter made more than enough castings to mix up over 15 gallons of tea!

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2011 Isadora

Comments

TinaD on June 12, 2017:

I tried outdoors but, while my worms did a wonderful job converting the scraps into compost, I can never find them afterwards. They either escaped or they died. =( So now, I'm using the large Folgers coffee canisters to try for an indoor kitchen composting system.

Deana Rogers on November 14, 2016:

Definitely need to try this idea out.

Just perfect for just me and my husband.

Then see how it goes and build from there.

Karen A Szklany from New England on November 23, 2014:

Gtrat idea, Jay. Enjoyed your hub.

Isadora (author) from Tennessee on June 30, 2013:

How many of you lovely ladies and gentlemen have tried out the coffee can composter? This was one of my favorite projects!

lapchickenlady on December 28, 2012:

always looking for ways to go green within my little world. will try this soon.

Isadora (author) from Tennessee on December 04, 2011:

Thank you so much Ann!

Ann C. on December 03, 2011:

I am totally using this design in my "how to compost with coffee grounds" speech. I will properly cite your article and ensure you get all the credit for the ingenious design.

juanforall from Q.C. MNL on August 02, 2011:

Nice hub, lots of helpful pics and the article is very helpful. I'll follow your profile ^_^

Isadora (author) from Tennessee on June 30, 2011:

Updated this at the Introduction for an easy way to harvest your castings!

Isadora (author) from Tennessee on May 12, 2011:

Thanks for the comment. Its fun-I just harvested some great castings from mine yesterday. I have them bubbling away making a tea for my garden.

Linda Crampton from British Columbia, Canada on May 12, 2011:

Thanks for the useful information. Building a coffee can composter sounds like an interesting project and the instructions don't look very difficult. I might try this soon!

Isadora (author) from Tennessee on March 16, 2011:

Thanks!

Yes, large scale needs bigger containers. Those drums are really useful! I've got mine as a rain barrel. You could totally take this design and make it using the drums.

I would build a frame if you're planning on stacking them. The would work really well standing alone though. There are YouTube videos showing how to build 55-gallon drum flow-through composters.

This is a really fun thing to do!!

50 Caliber from Arizona on March 16, 2011:

Halo, statue? Reckon a feller could take 3 55 gallon plastic drums for large scale operation and how you might figur the amount of moss etc for the barrels? I don't need a lot of "Red Wriggler Lechate", cuz' I just have one house plant, it's an annual, called a "tater butt" it appears when the weather hit 106 degrees out side. during those months it's not good for much but it does keep the weeds at bay.....lol.

Serious about the barrels and size and would you go by using 3 or just two. I have the blue and a few white, food grade barrels (If that makes a difference? probably to the worms?) and how much light gets in. A bag of the house plant soil and a container of jigglers from the bait store in a 5 gallon bucket and a deer head buried to the antlers, in 3-4 months the head is cleaned spotless inside and out, then the bucket holdings get added to tater mountain and mixed in, everyone tells me I'll have worms in my taters and I just say "wish you'd a told me that a ton or two of taters ago!"

great DYI, sorry it took so long to get here, peace, 50

Barbara Badder from USA on March 12, 2011:

This is a great idea. I might try it this year.