Introduction: Compost Tea Barrel

About: I am a Computer Engineering at my day job. The rest of my time I am want to be homesteader. I raise chickens, love gardening, love tinkering, and like to help others learn as well.

Learning more about composting brought me to an increased knowledge of compost tea. I even made it a few times in five-gallon buckets. I was surprised how well it worked and the many uses it has in the garden. It got to the point that I needed to make more of it to meet my gardening needs. I began to looking for the parts to make my own large brewer like what is used gardening stores. I knew this could be done with mainly recycled materials.


  • A large container that can hold about 35 gallons: Trash cans, barrels, etc
  • Bulkhead fittings something bigger than 1/2 inch
  • A valve that matches bulkheading size
  • Fittings to connect bulkhead to valve
  • Fish Tank air pump
  • Old sock or t-shirt
  • Paracord or some kind of cord
  • Big Wire spool (or some kind of stand for the container)


  • Drill
  • Whole saw kit

Step 1: Gather Your Materials

I was able to find a blue barrel for $5 from a friend. It was used to hold sugar so it will work great for this project. The valve and most of the fittings I found at a local Habitat for Humanity store. This place is often a great place to buy things cheaply for projects. I would also suggest local thrift stores. The bulkhead fitting I bought of Amazon for a few dollars. I bought a 1/2 inch threaded bulkhead fitting to match the valve and other fittings I got the Habitat for Humanity store.

For this stand, I went cheap and easy. I was able to get the old wire spool from an electrician working on a new school in the area. I showed up to the site just before quitting time and asked If I could speak to the electrician. After finding them I just simply asked if I could have one of the many spools that were next to the dumpster. They said, "Take as many as you want."

For the air bubbler, I reused one I had laying around from an old aquaponics system. These pumps can be found at thrift stores pretty regularly. I do recommend buying a large stone that will fit the pump. Larger pumps work better than the small one I used, but this one still did just fine.

Step 2: Drill Holes for Bulk Fitting and Airline

Choose a hole saw that will be a tight fit for the bulkhead. I did this by holding the bulkhead up to each whole saw. For the bulkhead I had, a 1 and 1/8 inch was perfect. I chose to use a hole saw to minimize the amount of plastic shaving created. The world has enough microplastics laying around, I don't want to add to them. I gather the plastic shaving as best as I could into a similar plastic container and then put them recycle bin.

I then drilled the same-sized hole in the lid of the barrel. This hole will be used to hang the compost bag and the air bubbler. A lid is not necessary but it helps to keep debris from falling into it or any kind of pests like flies or wasps. Wasps and other bees are attacked to the smell of the sugar in the compost tea.

Step 3: Inserting the Bulkhead Fitting and Valve

The bulkhead fitting is installed with the tube flange on the inside of the container with the nut on the outside. I pushed out the bulkhead fitting in then put the nut on finger tight. At this point, the fitting began to slightly spin in order to get it on tight enough that it wouldn't leak I needed to use some tools. To avoid damaging the threads I threaded a pipe into the fitting. I held on to this pipe with a small pipe wrench. I used some channel lock pliers to tighten the nut. Be careful to not overtighten the nut as this could lead to leaks around the seal. The wrench in the picture is bigger than the one used but the picture was cute and I felt like I had to include it. He wanted to be included in the project,

I thread together all of the pieces I wanted to use with the valve then thread it into the bulkhead fitting. For this valve, an old spigot could work as well but these fittings were cheap enough. I then set the barrel on the spool for the as a stand. The spool was bigger than the base of the barrel so I had to slide the barrel over so the valve would work correctly. I made sure I set it all up close to an outlet so the air bubbler can be powered. If you don't have an outdoor outlet you could set it up next to a window where an outlet can be used.

Step 4: Compost Tea Bag and Brewing

For the compost tea bag, I used an old sock. The sock allows water to move through it allowing the finer particles and microbes to be released. This sock had a hole in the toes so I had to tie a knot there. The compost can then be placed in the sock leaving just enough space to be folded over at tied with paracord. Make sure the paracord is long enough to hang about 6 inches from the bottom of the container. With a loop tied at the other end, a stick can be used to suspend it a crossed the opening of the container or hole in the lid.

There are lots of compost tea recipes out there. Many add lots of different kinds of organic fertilizers to give more. I usually do the basic.
1 sock of compost,(which I harvest from my bin)
1/4 cup molasses
35 gallons of chlorine-free water

Let it sit for at least 24 to 48 hours with air blubber in. Leave air bubbler running until the container is completely empty. Air is needed to keep the tea from going anaerobic. This can lead it to smell and will not work as well.

I have used plain sugar and corn syrup but molasses works the best. To get chlorine-free water just fill the barrel up with tap water and put the air bubbler in for 24 hours. The chlorine will evaporate out. I have even used water leftover from canning. This can be water used to blanch fruits and vegetables as well as used to cold bath bottles. The water that was used in blanching is often full of sugars and other micro-nutrients that help feed the microbes in the compost tea.

Feel free to comment and share your favorite compost tea recipes.

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