Aerated Compost Tea and Why Not to Use Compost Tea

How to make compost tea
At 4:27 why not to use compost tea

It’s no secret that we love compost tea. It’s what we use on all of our plants: fruits, vegetables, houseplants, medicinal herbs, and trees alike. But there are some reasons to consider not using compost tea.

1. Compost tea is essentially not replicable

Because your biology is going to vary throughout whatever compost you are using for the tea, it is difficult to replicate your tea recipe to get the same biology every time. You would have to have the compost quantifiably measured before every tea and somehow ensure that the same amount of each different type of microbe is going into your tea- not likely. Since you can’t ensure that the biology you are starting with is the same every time, it makes compost tea difficult to study and get any hard data on, and doing so would not even necessarily be beneficial because the conditions in which you are applying the compost tea vary so widely.

That brings me to 1-A: If compost tea is applied to an over-fertilized garden, (say a garden thickly laid with manure or a garden with heavy use of non-organic fertilizers), it can finally make the nutrients from the fertilizer available bringing the nutrient content of the garden from 0 to 60 in a second over-fertilizing the plants or over-heating the organic matter frying the plant roots. This only happens if a garden is already heavily fertilized-the garden already has a lot of nutrients, but they are locked and unavailable for the plants, the compost tea unlocks these nutrients and then all of a sudden there are too many of them. When applied to naked soil or soil dressed moderately with organic inputs, this doesn’t happen.

2. Lack of research and scientific data on the use of compost tea.

As we alluded to in reason number 1, there is a lack of published data on the benefits of compost tea. Because conditions are so variable, it would be hard to have any usable data on the benefits of compost tea.

3. Risk of pathogenic bacteria building up rapidly

Lastly, there is a reasonable risk of pathogenic bacteria contaminating your tea and potentially causing harm. If your compost is not fresh and has likely gone anaerobic, it can harbor more pathogenic bacteria that would compete with the beneficial bacteria that we are trying to cultivate. Also, if you use too much of a sugar source, this can also promote pathogenic bacteria. Brewing a tea for too long, (typically longer than 48 hours), will also increase your risk for “bad” bacteria in your tea.

As you can see, compost tea is not one of the grow methods that we use that is backed by hard science. But the anecdotal evidence is off the charts.

The first few times that we used compost tea on my lemon tree and it bloomed the next week, we weren’t sure if it was a coincidence or not. Now, that we have seen it happen so much, we are sure it’s the tea. The same goes for all of the other miraculous benefits we have witnessed: Rapid new growth overnight, pest control, extended fruiting time, more fruiting sites, less blight and mildew, and an increase in the plants’ disease resistance.

One customer who tried our tea at a market this summer told me that it brought her dead cucumber plants back to life, and I don’t doubt it. Another customer’s gardener asked them what the heck they were doing differently, the only thing they were doing was adding our compost tea. The benefits may not be scientifically explained yet, but they are real.

We often describe compost tea as “snake oil.” Meaning it’s one of these hippy remedies that doesn’t have hard science and works really well. (Now, just to be clear, we haven’t actually tried snake oil, it’s just an expression we use.)

Berkshire Worms 2021 Super Secret Compost Tea Recipe

1/4 cup/gallon of FRESH worm castings

1 tsp of alfalfa meal

1/4 tsp/ gallon Sea-90

a sprinkle of water-soluble kelp

Brewed for 24 hours with an air stone and aquarium heater

Compost tea has risks and benefits just like anything else, but in our experience, it is filled with benefits and is an economical way to spread beneficial biology throughout your gardens, feed your plants with available nutrients, and protect plants from pests and pathogens.