How to Make a Compost Tea


Compost is full of nutrients that make plants grow to their full potential. Compost is often combined with garden soil but it can also be used to make a tea that can be soaked up through the root system of the plant. Not only does it feed the plant but encourages beneficial organisms, reduces the chance of disease, and eliminates chemicals from the garden. The method of making compost tea is easy and can be made with an option to aerate the mixture with aquarium supplies or not.

Step 1

Cut the aquarium hose into three pieces each about 12 inches long or long enough to reach the bottom of one bucket. Attach each piece to the gang valve. Place the valve on the bucket and cover the ends of the hoses with duct tape

Step 2

Add one gallon mature, rotted compost to the bottom of the bucket. It must be mature enough that it is creating its own heat.

Step 3

Add four gallons water that has been sitting out for about 24 hours. City water has chlorine in it and this allows enough time for the chlorine to dissipate. Chlorine will affect the beneficial microbes in the compost tea adversely. Well water does not have to sit for this amount of time because there is no chlorine in it.

Step 4

Add 1 oz. of un-sulfured molasses. This feeds the desired micro-organisms. Stir well into the tea. This is an optional step.

Step 5

Remove the tape from the ends of the hoses and put them into the bucket. Attach the pump and turn it on. The pump oxygenates the tea, allowing for optimal microorganism growth and the tea is less likely to become stagnant. Stir the tea once a day with a paddle or large stick. Put the bucket near the garden in a warm sunny area if not using the pump method. It will have to be stirred two to three times a day.

Step 6

Brew for three to five days. When it is done it should smell earthy and sweet and not stagnant. If it does not smell right it should not be used.

Step 7

Strain the tea through cheesecloth into another bucket. Put the solids back into the compost pile and use immediately either full strength or diluted. If the pump was used it created many microbes and they will die off quickly without oxygenation. Get them into the soil around the plants before they cease to exist.

Tips and Warnings

  • If the tea does not smell earthy and sweet after five days there is not enough oxygen in the mixture. That is why using the aquarium supplies works so well. Oxygen is always being pumped into the tea and it does not need to be stirred as much. Use only mature compost that has rotted well. Raw foods are often part of compost and they need to break down before using so they do not contaminate the tea with E. coli. E. coli can leach into vegetables from the compost tea and cause illness.

Things You'll Need

  • 3 feet or more aquarium hose (optional)
  • Duct tape (optional)
  • 1 gang valve (optional)
  • 1 aquarium pump (optional)
  • 2 buckets used only for making compost tea, 5 gallon
  • 1 gallon compost
  • 4 gallons water
  • 1 ounce un-sulfured molasses (optional)
  • 1 strong stick or paddle to stir compost
  • Cheesecloth


  • Pennsylvania Dept of Environmental Protection: Compost Tea -- As Easy as 1,2 3
  • Sustainable and Urban Gardening: How to Make Compost Tea
  • Organic Gardening: Compost Tea

Who Can Help

  • Harvest to Table: How to Make Compost Tea
Keywords: making compost tea, brewing compost tea, compost tea application, tea from compost, natural compost fertilizer

About this Author

Deborah Harding has been writing for nine years. Beginning with cooking and gardening magazines, Harding then produced a gardening and cooking newsletter and website called Prymethyme Herbs in 1998. Published books include "Kidstuff" and "Green Guide to Herb Gardening." She has a Bachelor of Music from Youngstown State University and sings professionally.