Commercial-Quality Compost Tea

Let's begin this dialogue by defining non-commercial tea.

  • First, 'home-made' tea should not be sold on the open market due to the lack of controls, data collection and variability of too many inputs.
  • Second, the home-brew maker MUST take personal responsibility for the tea quality and consistency even if they give it away. Granted, it's really hard to make bad tea - but it is possible - and bad tea can be harmful.
  • Third, the tea may be any kind or type of the large variety of teas that can be made from manure, or manure-based compost that can contain human pathogens - and the source of compost is THE primary factor. NEVER make tea from a bag purchased at a 'big-box' store.
  • Fourth, the tea may or may not have been aerated, and even if it was, it could have become anaerobic - which can produce toxins that are harmful to plants and people.
  • Fifth, the tea may or may not have been 'activated' or 'fortified', and if not, will likely not contain the foods necessary for microbes to 'settle-into' their new environment when applied.
  • Sixth, the equipment used to make home-brews can vary greatly, and not provide an adequate brewing environment - particularly by using under-powered air movement equipment which does not provide and maintain the minimum 6ppm dissolved oxygen level needed for a tea to be aerobic.

On the other hand, there are some very good brews made by individuals who have studied this science-based art form and use the right kind of equipment AND testing devices.

So then commercial-grade compost tea is:

  • AACT - Activated Aerated Compost Tea

Activation means that microbe foods were added so that microbes in the tea had the proper balance of protein and carbon supplied in the tea water during the brew, to support exponential reproduction)
Fortified means that a balance of carbon and protein microbe foods were added to the finished tea batch, to feed the volume of microbes after application.
Additional requirements of commercial-grade AACT are:

  • tea was brewed at greater than '''6 ppm DO (tested with a dissolved oxygen meter) and at no time was permitted to become anaerobic during the brew.
  • Microbiology in the tea is established by DIRECT OBSERVATION through a 400x light microscope to determine the bacteria to fungi ratio (B:F).
  • Tested to ensure that coliform bacteria were within acceptable tolerance and high CFU of E.coli are not present.
  • Tea has been fortified to sustain microbes after application.
  • Only 'high-grade tea-quality compost was used as basis for the brew; light microscope tested by qualitative assessment, to ensure microbe diversity, and was pre-treated if necessary, prior to brewing.

Commercial quality tea can be brewed to greater strengths by extending the brewing time, but additional foods must be applied at the right intervals, and a close watch kept on DO level, pH and temperature of the brew.

The ROI Laboratory classifies tea brews as:

  • Concentrate ~ 24-hour brew
B:F target at 1:.5
  • Super Concentrate ~ 48-hour brew
B:F target at 1:1
  • Super-Ex Concentrate ~ 72-hour brew
B:F target at 1:1.5 or greater

Brewing a high-bacterial tea is easy with the right equipment and understanding of the process, and high-bacterial teas are best for certain plant conditions.

High-fungal teas are more difficult to brew because the percent of dissolved oxygen and balance of microbe foods must be monitored more closely and direct assessments made more often, to determine the degree of fungal growth. It takes time for fungi to grow in solution. High-fungal teas are best for treating plant diseases and protection from certain plant conditions.

Maintaining proper aeration levels during transport and application; proper mixing of concentrates and maintenance foods into carrier water; and achieving effective application rates are also responsibilities that a client will expect from a commercial tea-brewing enterprise.

More on this subject coming soon...

Click Here to see: Compost Containments
Click Here to see:COMPOST PILES