Compost Teas: 24 hour, EM, IM, BD & fermented plant extracts

[Soilfoodweb AT aol.com]

In response to the questions about temperature -

As organisms grow in the compost tea maker, their metabolic heat increases the temperature of the water.  The warmer the water, the more rapid the growth rate of the organisms, and the more likely oxygen use by the microbes will outstrip the ability of the aerators to meet that aeration demand.  

In tea pump systems, where the tea goes through the pump, the pump may lend some heat to the system above and beyond the temperature given by the organism
growth.

In air pump systems, where the tea is mixed by the air bubbles going through the water, temperature may remain at ambient levels, because the ambient air temperature cools the tea.  

Temperature in tea is important, because if the temperature is too low, the tea is not finished at 24 hours.  In fact, some tea machines won't reach the maximum growth rate until well after 48 hours.  

If you take a tea before it is "mature" and reaches stable activity levels, placement of the tea in a shipping container will result in an anaerobic tea.  This may be one reason for highly variable results that are seen after shipping.  If an immature tea is shipped, the tea may go anaerobic and the fungal biomass may be lost, or the activity of the bacteria may be affected.  So, only fill the containers 1/4 to 1/2 full, and make sure the tea is in the mature, not-longer-rapidly-growing stage.

If the temperature rises to high levels as in some Microb-Brewers, one concern is that the organisms that grow will be not-adapted to the temperature of the soil.  Typically, the temperature in any Microb-Brewer is not over 95 degrees Fahrenheit, so the temperature is not that great.  Typically, temperatures are only a few degrees elevation over ambient is reached in any tea machine. These temperatures are not that unusual for many soils during warm summer day.

If you are concerned about the species of bacteria or fungi selected at higher temperatures, then cool the tea temperature to the temperature of the soil, but then recognize that you may need to run the brew cycle for a longer time, if the maximum growth rate has not been reached by 24 to 48 hours.  

Hope this helps!

Elaine