Brewing Worm Tea

If you have been learning about vermicompost and its uses, you may have come across worm tea/vermi tea. However, worm tea is often misunderstood. Read on to learn what worm tea is and what its uses are.

What Is Worm/Vermi Tea?

It is a common misconception that the leachate that collects on the bottom of your worm bin is worm tea. This is untrue. Adding to that, leachate may even contain bad bacteria, and is not recommended for use in large amounts. On the other hand, vermi tea is made by steeping vermicompost or vermicast in water, sometimes accompanied by other ingredients such as molasses in order to keep the microbe population active. In theory, when used to water plants, or sprayed on plant foliage, it encourages the growth of beneficial microorganisms that protect plants and encourage plant growth. It also inoculates your plants with the many nutrients and micronutrients worm castings contain.

Vermi Tea is often expected to provide loads of nutrients for your plants. Although vermi tea is truly rich in nutrients, its microorganism content is what makes it special. The good bacteria in vermi tea help condition the soil, fight harmful bacteria, and improve the ability of plants to absorb nutrients.

How Is Vermi Tea Made?

As implied by its name, vermi tea is made in a somewhat similar fashion as tea. For traditional vermi tea, first, you must encase the vermicompost in a semi-permeable material that will not let the worm castings through, such as a cheesecloth, or a fabric bag. Around 3 cups of vermicompost is recommended for an average sized bucket of water. Then, a source of water would be needed. We recommend you use room temperature dechlorinated water, aged water, or rainwater, as chlorine from fresh tap water can kill beneficial microbes. We also recommend adding around a tablespoon of molasses for every 5 gallon bucket of water. 

While steeping the vermicompost “tea bag” in the molasses-infused water, mix it gently in order to aerate the water, and keep the good aerobic bacteria alive. The vermi tea will be ready in about 15 minutes. The remaining vermicast/vermicompost can be used in the garden as mulch/fertilizer.

Although the traditional method described above is easy and effective, if you are willing to put in more time and effort, you can make a much more bioactive and potent vermi tea. You can do this by steeping the vermicast in the water for an extended amount of time, accompanied with a source of aeration, such as tubing connected to an aquarium pump. The brewing time can range from a few hours, to even a couple of days, depending on your preferences. For a good middle ground, we recommend brewing the vermi tea for around 12 hours, or overnight. 

Because the worm tea will be brewing for an extended amount of time, the aerobic bacteria need aeration, provided by an aquarium pump, and a food/sugar source, in the form of molasses. The bacteria will use the molasses as a food source overtime, so we recommend adding an additional tablespoon of molasses for every 12 hours of brewing. For example, a brewing time of 12 hours would need (1+1) = 2 tablespoons. If brewing for more than 24 hours, make sure not to add all the molasses all at once, or you will end up with a sticky, sugary mixture. Again, after brewing, the remaining vermicast can be used as normal.

How Should I Use Vermi Tea?

You can spray vermi tea on plant foliage to protect plants from pests and disease. Alternatively, you can water the plants directly, in order to condition and fertilize the soil, helping your plants grow healthier, and stronger. Remember, a little goes a long way.