Compost tea is a brewed water extract of compost containing billions of beneficial microbes per liter. Compost is placed into a bucket of water and air is pumped into the bottom of the bucket for about 24 hours. In that environment, aerobic [oxygen loving] bacteria, protozoa, and fungi multiply and flourish. The reason ordinary compost is good for your garden is because of the presence and activity of those microbes. The benefits of compost tea are the same as regular compost, but multiplied by at least 1000.
Without the additions of any fertilizers, your plants will develop deeper root systems, healthier foliage, tastier fruit, and more beautiful flowers. The beneficial microbes present in the both the root and leaf zones will help ward off diseases and insects as well. Therefore, the need to apply products for disease and insect control is either reduced or eliminated in gardens, vineyards, farms, and on lawns. It is a win/win/win situation.
We are promoting the aerated aerobic style of compost tea. The reason for that is because —in general—aerobic microorganisms tend to be beneficial while many anaerobic [oxygen avoiding] microbes can be considered human and plant pathogens. The aerobic style is by far the most popular because it is the most powerful, safest, and easiest to make.
We are not promoting the use of compost leachate, manure tea, or steeped tea without aeration [stick method] . The fact that the common term “compost tea” has been, and is used to describe all of these methods has created some confusion.
However, we are also promoting the use of EM®1, which is a very powerful set of microbes discovered in Japan 30 years ago. EM®1 is not compost tea, but may be used with it. Mixed together, or used in alternating applications, the use of both compost teas and EM®1 may be the best thing you can do for your plants.