What frass tea is

Frass tea (sometimes “frass extract”) is made on purpose: solid frass is soaked or brewed in water, often aerated or fermented, then strained for foliar or soil application. It is a derived product—unlike leachate, which is incidental runoff from the bottom of the bin.

Terminology online is messy. Posts that say “frass tea” may mean leachate, compost extract, or diluted frass slurry. When reading research or sales copy, check whether the author started from separated solid frass or from raw drain liquid.

Why people make it

Tea can deliver soluble nutrients and microbial metabolites faster than top-dressing dry frass—similar in spirit to compost tea from other organic amendments. Recipes vary: steep time, aeration, dilution ratio, and whether the frass was composted first all change the result.

Cautions

Aerated teas can harbor pathogens if feedstock was contaminated or brews go anaerobic. Dilute before application on tender plants. Regulatory treatment of liquid organic fertilizers differs by region—same as for solid frass, verify local rules before selling or broad broadcasting.

Research trail: Frass vs leachate vs frass tea.