It is well known that all organic waste from UKY Dining facilities is recycled into nutrient-rich compost. This product is brought back to campus, where it is used by UKY’s Grounds team members as a soil amendment to build better soil. We have added another upcycling step to the process, brewing batches of compost tea, 200 gallons at a time.  

Compost Tea has numerous advantages to other soil amendments: 

  • increases biodiversity of soils with high concentrations of beneficial fungi and bacteria 
  • increases water-retention properties of soils, reducing watering needs 
  • absorbs faster by soils and more quickly enhances soil and plant health 
  • is more sustainable than synthetic fertilizers  
  • can be sprayed directly onto foliage 
  • can be made simply 

The process utilizes an industrial size teabag filled with about 2 gallons of dry compost and other beneficial additives. The teabag is then submerged into a 200-gallon customized brewing tank, where it is aerated for a few days. This aeration process is critical as it creates an aerobic, oxygen-rich environment where beneficial microorganisms can multiply and thrive.

Once the batch is ready, it is transferred to a trailer-mounted tank outfitted with its own aerator to keep oxygen flowing. With an onboard transfer pump and hose/reel/sprayer, the finished product can be hauled most anywhere on campus and applied to trees, turf, shrubs, flowers, etc. The whole brewing system is broken down and rinsed, and the process starts over by dechlorinating water (with the same aerator) for the next brew. The apparatus’ max capacity is three 36-hour 200 gallon brews a week, making 600 gallons of tea that can be diluted into 1200+ gallons. The product was used during hot dry stretches this summer to fertilize and water about 150 trees weekly. In between brewing cycles, we can use the tank and pump to water plants in need.  

As we brew more batches, gain more data, and apply a little science, our Grounds team will be able to adjust our brewing process to create batches that are suited specifically for different seasons or horticultural needs. Currently we are treating recently planted trees and intensive horticultural areas and treating a tree near you! Let us know if you see any trees or plants that need a compost tea boost.  

Ritchie Katko


  • Awesome article! Compost teas are a wonderful use of plant matter and compost to make it go further.

    This year in my own garden I’ve been practicing anaerobic compost teas. I was inspired by the JADAM gardening book which loosely follows Korean Natural Farming techniques.

    The anaerobic tea benefits from not needing an air pump and doesn’t have a ‘shelf life’ of when it has to be used. I’ve got teas that are a few months old, smell absolutely wretched and are getting better every day! It’s been an excellent experiment and has been working wonderfully for me.

    I’m not sure it’d be perfect for the campus grounds though. The smells are quite… unpleasant to the untrained nose.

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