Activated Compost teas

Compost tea brewer in action


Compost teas are easy to make and simple to apply. They are really just a brew of nutritious organic materials that are diluted and either sprayed as foliar sprays or added to the soil at the root zone.

To make them extra potent, a Compost Tea Brewer can continuously mix the ingredients by bubbling air through the solution. This also gives a boost to the beneficial microbes that will break down the components of the tea into forms that are more accessible to the plants. It helps reduce the time required to make the tea drastically.

Any organic material that can be added to a compost heap can be used.  Here’s a few of my favourite ingredients –

  • Worm castings
  • Nettles
  • Yarrow
  • Comfrey leaves
  • Chicken poo
  • Molasses
  • Bokashi liquid (from the bottom of the Bokashi bin, not the stuff you spray onto the veggie scraps)
  • Dolomite

All of these are well known composting ingredients (except, maybe the Bokashi liquid).

Worm castings are a cornerstone to all of my compost teas. They are well known for their amazing range of plant nutrients. Nettles too have a formidable reputation for their nutritional content and make a well known tea in their own right.

Yarrow and Comfrey are known as ‘compost activators’. they have compounds in them that help speed the composting process through enhancing biological or chemical reactions in the compost pile.

Chicken poo is a well known fertilizer that is full of nitrogen. That nitrogen boosts microbial activity quite well.

Molasses gives a food source to micro-organisms. This isn’t highly beneficial in the soil, as it does cause quick spikes in the microbe population that it feeds but these populations crash when this easy food source is used up. For our purposes though, it can increase microbe activity during the relatively short time we’re making the tea and help break down the organic materials into substances that can be more readily uptaken by the plants or soil biota.

Bokashi liquid adds a whole heap of microbes to the mix. Even though the Bokashi process is anaerobic, if it is exposed to air for a while, it becomes colonized by areobic microbes that use it as a food source.

Dolomite or rock dust has some minerals in it, but I mostly add it to the mix if it is too acidic.

For a compost tea brewer such as I covered on its own page, I use a 60 litre bin. To this I add –

  • 200g worm castings
  • 100g dried nettle leaves
  • 100g chicken poo
  • 1/4 cup molasses
  • 1/4 cup Bokashi liquid
  • a good handful of Comfery or Yarrow depending on how much is growing in the garden
  • usually a small handful of dolomite
  • sometimes a splash of urine if I’m feeling daring.

These ingredients are added to 60 litres of rainwater and put into the compost tea brewer where air is bubbled through for about 4 hours, allowed to rest and bubbled again for another 4 hours. It is then left to ‘age’ for a day and is ready to go after filtration.

Before the I got the compost tea brewer idea from YouTube, I would let ta similar mix sit for a fortnight before using it.

You can see from the ingredients that I consider the microbial population and activity to be the prime driver of a good compost or tea.

Be creative with your mix, there are hundreds of ideas online. You can even just get existing compost and soak it in water for a couple of days before straining it and using the resulting liquid.

It’s that easy!


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