Not for human consumption, guano tea is a steeped combination of bat guano and water used to fertilize plants. The tea is best when brewed with warm water. Cold water slows the growth and reproduction of microorganisms that break down the guano, and hot water limits the oxygen available through the brewing process. Temperatures between 60 and 90 degrees Fahrenheit are best for brewing, which is done in a store-bought or homemade brewer.
True Brew
Guano tea can be created by filling a 5-gallon bucket using distilled water and putting it from direct sunlight. Put a heater at the water, and also increase the water temperature to 75 F. When the water is warm, then fill a composting teabag using guano, and set it in the water. Insert microbe food such as 1.6 ounces of molasses or even 0.3 ounce of fish oil emulsion. With an aerator from the bucket, the tea mix should brew 12 to 48 hours. After turned off, the aerator and heater can be washed thoroughly. Use the tea to fertilize plants. The mixture can be used as is for a soil drench or strained and applied as a foliar spray twice every month.
Speedy Method
If you need only a small amount of fertilizer for container plants, you can shortcut the brewing process. Add 1 tablespoon of guano to 1 gallon of water, and allow the mix to sit 24 hours. Your plants won’t get the utmost fertilization benefit in this manner, but they will find some.