At the most basic Compost tea is water containing microorganisms and compost. Just like your gut microorganisms help you digest food and keep you healthy. Soil microorganisms do the same for soil and plants. Compost is a great way to feed and maintain a healthy soil. Those microorganisms that break down organic matter into compost are part of what makes compost so great. When brewing compost tea the goal is to create a higher concentration of those microorganisms.
There are 2 main categories that compost tea is broken down into aerobic and anaerobic. Aerobic simply means microorganisms that they breathe oxygen. Anaerobic means the microorganisms don’t breathe oxygen. Anaerobic microorganisms produces gases like methane. Garden plants grow better in soil populated with aerobic microorganisms. Soil at the bottom of a pond is an example of anaerobic soil.
I am far from an expert on compost tea. When I started gardening in the 90s I heard about compost tea and made what I now know was anaerobic compost tea. I now know that aerobic would be have been better. It still grew great plants! It had an unpleasant aroma. I made it in a 55 gallon barrel and a burlap bag. Over time researchers have learned more as a result more information becomes available all the time. I followed instructions for many different brewers always ending with up foul smelling liquid. I now have a better understanding how much air is required for get aerobic compost tea. One of the best sources of information backed by demonstrated evidence can be found at http://www.microbeorganics.com From there I learned that I you need 0.5 to 0.0.8 cubic feet of air per minute per US gallon. That you need to maintain 6 PPM of dissolved oxygen.
The goal in making compost tea is to provide an environment in which soil microbes multiply in large numbers. The term tea doesn’t actually make sense, until someone comes up with a better word we use it.
Why use compost Tea
Many agricultural, gardening and landscaping practices have negative effects on soil life. Soil life is an integral part of the nutrient cycle. The soil microbes provide plant available nutrients for plants to grow and develop strong defenses against pests and disease. Compost tea is one tool you can use to rebuild a living soil. Compost tea is like the probiotic foods people eat it replenishes the soil life.