Home How to Build a Compost Tea Brewer and Brew Tea

How to Build a Compost Tea Brewer and Brew Tea

user profile picture Phil Williams Feb 01, 2016
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I had a free 55 gallon barrel that I decided to turn into a compost tea brewer. Compost tea is a great way to magnify your compost by breeding the beneficial microorganisms and spraying them on your plants. Plants sprayed with high quality compost tea will be healthier, less affected by pests, and produce better fruits and vegetables.  

Tools Needed

  • 1.25 inch hole saw bit and drill
  • Skil saw with wood blade
  • Pipe wrench

55 Gallon Barrel

Materials Needed

  • 55 gallon poly barrel
  • 1.25 inch brass bulkhead fitting
  • .75 inch brass hose bib
  • 1268 GPH Pump
  • Tea Lab Aeration Hose
  • Thread seal tape
  • Tea Lab mesh bag

Hole Saw Bit, Spigot, Bulkhead Fitting

  1. The first thing I did was cut the entire top off the barrel. I used a skil saw with a wood blade on it. This may not be the best way to do it, but it worked. It did make tons of plastic shavings to clean up, so do this on concrete. Once the top was cut off, I could flip it over, and it made a perfect cover for the barrel.

Top cut off barrel

  1. Next, I drilled a 1.25 inch hole near the bottom of the barrel. I used a 1.25 inch hole saw drill bit.

Hole Saw Cut

  1. I reached down in the barrel and screwed in the bulk head fitting so the threads point out, with one of the rubber gaskets inside.
  1. I added the other rubber gasket to the outside of the bulkhead fitting and screwed the nut on the end, gently tightening with a pipe wrench. Be careful not to overtighten, as it can break the barrel and cause a leak.
  1. I added thread seal tape to the spigot.
  1. Screw the spigot into the bulkhead fitting. I hand tightened this and with the tape it did not leak.

Spigot Installed

  1. I chose a place upslope from where I planned to spray that was close to water and electric. I leveled the area and added cinder blocks for the barrel to sit on.

Platform for Compost Tea

  1. I added the plastic aeration hose, and hooked it up to the pump.

Aeration Hose

  1. I ran an extension cord to the pump.
  1. The brewer is ready. Add water. If you have well or rain water, aerate for 20 minutes before adding compost and ingredients. If you have city water, aerate for 24 hours to off gas the chlorine.

Filling the barrel

  1. Add finished compost to the sealed mesh bag, and put into the water. Hang with a clip.

Clasp to hold bag of compost

  1. Add whatever food you want to supply the microorganisms and your plants. I used a cup of molasses and liquid kelp.

Compost Tea Ingredients

  1. Then aerate your brew based on the water temperature.  
  • 80 degrees: 12 hours
  • 70 degrees: 24 hours
  • 60 degrees: 36 hours
  • 50 degrees: 48 hours

Compost Tea Brewing

  1. If the brew smells bad, do not put it on your plants, it has gone anaerobic. If it smells good and earthy, great, put it on your plants. Once the brew is done, use it all immediately.

~ Phil Williams

Phil Williams is a permaculture consultant and designer and creator of the website  He is also the author of numerous books, most recently, Fire the Landscaper and Farmer Phil's Permaculture. His website provides useful, timely information for the experienced or beginning gardener, landscaper, or permaculturalist. Phil's personal goals are to build soil, restore and regenerate degraded landscapes, grow and raise an abundance of healthy food of great variety, design and install resilient permaculture gardens in the most efficient manner possible, and teach others along the way.