Can Compost Tea Go Bad?

by Alex Kountry
Updated on

Can compost tea go bad? Yes, it can! Here’s what you need to know about how to store your compost tea, and what signs to look for that indicate it’s time to make a new batch.

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Many gardeners love compost tea because it is a great way to give their plants a nutrient boost. Compost tea is made by steeping compost in water, and it can be used as a liquid fertilizer or sprayed on the leaves of plants as a foliar feed. Because compost tea is made with organic materials, it is safe for both people and the environment.

Compost tea can go bad, however, if it is not made or stored properly. If you are thinking about making your own compost tea, be sure to follow these tips to ensure that your tea is fresh and effective.

What is Compost Tea?

Compost tea is an infusion of water and compost, often with the addition of other organic matter such as manure, molasses or seaweed. The mixture is aerated and allowed to steep for a period of time, anywhere from 24 hours to several days. The finished product can be applied to the soil or used as a foliar spray.

Compost tea has become a popular gardening tool in recent years, due in part to its purported ability to improve plant health and reduce the need for chemical fertilizers and pesticides. It is also relatively easy and inexpensive to make at home.

However, some gardeners have found that their compost tea goes bad quickly, developing an unpleasant odor and slimy texture. If this happens, it is important to understand what went wrong and how to prevent it in the future.

There are two main reasons why compost tea can go bad: poor aeration or contamination with pathogens.

Poor aeration can occur if the mixture is not aerated properly during the steeping process. This can happen if the container used is not large enough or if the air pump is not powerful enough. As a result, the oxygen level in the mixture decreases, causing bacteria to grow and producing ammonia, which gives off a foul odor.

Contamination with pathogens can occur if dangerous bacteria or fungi are present in the compost or other organic matter used to make the tea. These pathogens can cause serious illnesses in humans and animals if ingested. To prevent this, it is important to use only high-quality compost and other materials, and to sterilize all equipment before use.

The Benefits of Compost Tea

Compost tea is rich in nutrients and beneficial microbes, making it an excellent addition to your gardening routine. However, like any organic material, compost tea can go bad if it’s not properly cared for. Here are some tips to keep your compost tea fresh and effective.

-Store compost tea in a cool, dark place.

-Brew fresh compost tea every two weeks or so.

-Avoid using treated or chemically enhanced water to brew your compost tea.

If you follow these simple guidelines, you can enjoy the benefits of fresh compost tea all season long!

How to Make Compost Tea

Compost tea is an aerated solution of water and compost that is used to add nutrients and beneficial microorganisms to the soil. The Tea can be made with finished compost or worm castings, but it is most commonly made with compost that is in the process of decomposing.

To make compost tea, you will need:
-5 gallons (19 L) of water
-1 gallon (3.8 L) of sifted compost
-An aquarium air pump
-An air stone
-An organic fertilizer such as kelp meal or fish emulsion

1.Fill a 5 gallon bucket with water and set it in a shady spot outdoors. The water should be from a non-chlorinated source such as rainwater or distilled water.
2.Add the sifted compost to the bucket of water and stir it until the compost is fully saturated.
3.Attach the air stone to the aquarium air pump and place it in the bucket of compost tea.
4.Turn on the air pump and allow it to run for 24 hours, or until bubbles are no longer coming from the air stone.
5.After 24 hours, turn off the air pump and remove the air stone from the bucket.
6.Stir in 1 cup (237 ml) of organic fertilizer per 5 gallons (19 L) of tea.
7.Pour the tea into a watering can or sprayer and apply it to your plants immediately, or store it in a cool, dark place for up to 3 days

How to Store Compost Tea

While compost tea will not go bad in the sense that it will spoil or make you sick, it will lose its potency over time. For this reason, it is important to store compost tea properly so that you can get the most benefit from it.

Compost tea should be stored in a cool, dark place. A refrigerator is ideal, but a dark cupboard or closet will also work. Be sure to keep the container tightly sealed so that the tea does not dry out or become contaminated by outside bacteria.

When stored properly, compost tea will remain potent for several weeks. After that, its beneficial bacteria will begin to die off and it will no longer be as effective at helping your plants grow.

Can Compost Tea Go Bad?

It is possible for compost tea to go bad, but it is not common. If you are brewing compost tea using a aerated compost tea brewer, you should be able to tell if your tea has gone bad by the odor. Bad compost tea will smell sour, like alcohol that has gone bad.

If you are unsure if your compost tea has gone bad, it is best to err on the side of caution and discard it. It is not worth taking the risk of using bad compost tea on your plants.


In conclusion, compost tea can go bad if it is not used within a few weeks or if it is not stored properly. If you notice that your compost tea has an off smell or appearance, it is best to discard it and start fresh.

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About the author

Alex Kountry

Alex Kountry is the founder of HayFarmGuy and has been a backyard farmer for over 10 years. Since then he has decided to write helpful articles that will help you become a better backyard farmer and know what to do. He also loves to play tennis and read books


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