There are tens of thousands of different species of microorganisms that have a huge part to play in the health of your garden.
They kill diseases, feed and protect plants, improve the soil, and perform a long list of other jobs.
In 2006, I was running my organic gardening business and learning that my clients’ gardens were deficient in proper biology.
And luckily I had just finished reading ‘The Compost Tea Brewing Manual’ and studying compost tea in general, and discovered the importance of bringing these important microorganisms back into the garden.
So I decided to try it. I started with the highly recommended KIS compost tea brewer – one of the first and still best tea brewers on the market (based on independent lab testing) – and I never looked back.
Even compost tea guru Elaine Ingham of Soil FoodWeb Inc. recommends the KIS brewer as being one of the best brewers.
“The KIS brewers are extremely easy to set up and use, very easy to clean, and make great teas by extracting all the species of bacteria, fungi, protists, and nematodes present in the compost into the tea. Using the right resources, the KIS brewer can get fantastic fungal biomass growing in their tea maker.
Using the KIS starter foods and compost, we have never seen the KIS brewer have a problem maintaining aeration. Even if “poor compost” has been used, where E.coli and other pathogens were in high numbers, these problem organisms have been dropped to less than detectable levels by the proper use of this machine.”
Dr. Elaine Ingham, Soil Microbiologist
“From the instant I got my KIS brewer, I knew it was going to be fun. The instructions were so simple that I set it up in about three minutes and turned it on before I went to bed. I used the tea in our greenhouse the very next morning (14 hours later instead of 12, but that was only because I slept in!). It was a fine looking brew with a great smell, good feel, and excellent color.
I was quite sure my plants would appreciate it and I couldn’t wait until the snow melted and I could get out and use the KIS-made compost tea on our gardens and lawns. Am I pleased with my KIS? Just try and take it away from me. Thanks for this important machine. It will change the world. I know it has changed the way we garden here in Alaska.”
Jeff Lowenfels, author of ‘Teaming With Microbes’
What Is Compost Tea?
The right side of this tree was sprayed only one time with compost tea from a KIS compost tea brewer, along with liquid fish fertilizer.
The leaves are so much more abundant, bigger and healthier on that side, actually hiding the cherries from view.
The purpose of compost tea is to reintroduce beneficial microorganisms into our gardens that ideally would be there in the first place, but often aren’t any more for many reasons.
As with mycorrhizal fungi, that includes past tilling, topsoil removal during construction, environmental pollution, pesticide/chemical fertilizer use, and so on.
Those microorganisms are largely responsible for the health of our plants. They help:
- Increase plant nutrient uptake, making your plants bigger and healthier
- Not only prevent plant disease but can even get rid of existing disease
- Increase water and nutrient retention in the soil, so your plants get more of both
- Breakdown toxins in the soil and on plant leaves
I mainly think about it as boosting plant health, which ultimately means more nutritious food and fewer pests.
Unlike SCD/EM, the tea is also a broad spectrum organic fertilizer of soluble nutrients that can be immediately used by both microorganisms and plants.
By the way, be sure to read the comparison to both SCD/EM and mycorrhizal fungi on the right side of the page.
How To Make Compost Tea
Back to what compost tea is. To be clear, when I say compost tea, I mean the modern version, which is ‘aerated’ compost tea.
Some people even say ‘actively aerated’ compost tea, which means we use an air pump to aerate, not just a stick to stir the tea once in a while.
Compost tea traditionally meant compost that was left in a bucket for a few days and perhaps stirred a few times, and it can have some benefits, but a quality aerated compost tea with an air pump is going to be much more useful.
In case you don’t know, here’s how to make compost tea. Air is bubbled through a bucket of water that contains a bit of quality compost and other ingredients.
The bubbles pull the microorganisms off the compost (as otherwise they’re kind of glued on there) and also give air for the microorganisms to breathe.
That’s important because we want to create a compost tea of mostly air-breathing (aerobic) microorganisms, as they tend to be the beneficial ones for our organic gardens. Of course, there are some not-so-good aerobic microbes, too, but many more are good guys.
Then the other ingredients are foods like liquid kelp and liquid fish and molasses that feed the microorganisms and cause them to multiply like crazy.
When it’s done, we have a solution with trillions of beneficial mostly aerobic microorganisms that we can spray into the garden (maybe even quadrillions if you did a good job).
One reason this is useful is because while there’s often not enough compost to adequately cover the garden, compost tea goes a lot further.
So if you haven’t been using compost, compost tea is going to bring many of the same benefits, other than the organic matter.
But even more interesting is that we can spray compost tea right onto plant leaves where the microbes will feed them nutrients and protect them from disease – in fact, if you make a good tea and get your leaves covered fully, it will be very difficult for diseases to live there.
It can’t be marketed as controlling disease because it’s not a pesticide, but we have clear research showing that the microorganisms in good compost tea keep disease populations in check.
DIY Compost Tea Brewer
A lot of people want to make a diy compost tea brewer, and it’s certainly possible.
There are a lot of factors that affect tea quality, though, so if you want to make a good tea that brings in the big benefits, be prepared to do some lab testing and tweaking of your brewer to get it right.
But if you really enjoy tinkering and you have a bit of money to spend on lab testing, I could see that being fun even though you’ll end up paying more.
Most homemade compost tea brewers don’t cut it, so the most important advice I can give is to make sure you get a good air pump that pushes a lot of air – not a little aquarium pump like a lot of people on the internet suggest – that won’t make a tea that does much of anything.
The EcoPlus Commercial Air 5 is a great one, or even the Commercial Air 3 would be better than a little aquarium pump.
I figured out that it would actually be much more affordable to use a tea brewer that’s already been thoroughly tested, so that’s what I’ve always done.
So while I’ve played around with making my own brewer, I never did any testing because I already had a KIS brewer that was working great.
The KIS Compost Tea Brewer
These brewers are easy to clean, which is really important because we want to work with a clean brewer every time we’re making compost tea.
And they make exceptionally high-quality compost tea (well tested and documented), with a very reliable air pump.
KIS Brewer – The Original Brewer.
It takes 24 hours to make a tea, and the pump will last you for at least a few hundred brews (basically forever).
It’s a good choice if you plan to brew more often, like monthly.
It’s kind of like a small commercial compost tea brewer. $300.
Mini-Microbulator – The New Brewer.
It takes 36 hours to make a tea. The pump is louder and it doesn’t come with the 3 food kits or a bucket, but it still makes a great tea.
This is more for do-it-yourselfers who already have a bucket (or will get one at a hardware store) and already have compost to make the tea (although you could buy the kits separately if you prefer). $130.
What Comes With The Compost Tea Brewers
The KIS Brewer comes with 3 separate brewing kits that each include a small amount of compost and a mixture of foods to feed the microbes in that compost. That’s all you need.
The Mini-Microbulator doesn’t come with the kits, although you could buy them separately.
Then you can buy additional kits when you’re ready, or you can also use your own compost and microbes foods.
But the nice thing about the kits is that the quality of the compost is excellent. It’s actually a mix of Alaska humus and worm compost (vermicompost) and fungal compost.
Then, the mixture of foods has been thoroughly tested with these brewers.
What that means is the compost tea produced from these brewers has been tested in a lab with this specific compost and this specific food mix under the recommended brewing conditions, and it makes a great tea, so all you need to do is follow a few simple rules you will have a great compost tea.
FYI, the kits are derived from sulfate of potash magnesia (aka sul-po-mag or k-mag), feather meal, soymeal, cottonseed meal, mycorrhizal fungi, kelp, and alfalfa meal. It’s registered organic, so all non-GMO.
How To Use Compost Tea
A decent 5-gallon brew will cover an acre of garden, but even if you only have a tiny garden, you can spray the whole batch of compost tea and that will be even better – it’s impossible to over apply it.
You don’t want to use a hose end sprayer for compost tea because the container is far too small, and also because we mostly want to use it undiluted (i.e. not mixed with more water) in order to get the maximum concentration of beneficial microorganisms on the leaf surfaces.
That’s where a different kind of sprayer comes in – either a backpack sprayer or one that sits on the ground. Here are links to 3 of my favorites:
1. Chapin – $130. Tad Hussey, who’s in charge of manufacturing the compost tea brewers on this page, recommends the Chapin 1949 concrete sprayer. Being made for concrete, it has big enough filters to allow beneficial fungi through. I recommend home users get this one.
2. Rittenhouse – $150. It seems this one isn’t available anymore, but it was made for compost tea. It could handle the bits of solids that are often in the tea and it was a good price. It sits on the ground instead of on your back, which is good if you don’t want to lift up too much weight onto your shoulders.
3. Birchmeier – $250. This brand of sprayers can get very expensive, but it’s one of the best on the market, so they don’t leak and break down as much as most other sprayers.
While Solo sprayers are popular among compost tea users, they have a lot of problems when compared to the sprayers from Birchmeier.
But all backpack sprayers including the Birchmeiers aren’t designed for compost tea, so you’re going to want to do a good job straining the tea first to get rid of any solids. And then it’s a good idea to go so far as to buy some 400-micron screens from a hardware store to replace the screens in the sprayer (by following the parts diagram) in order to make sure more of the beneficial microorganisms can get through the sprayer.
One other method that some people use successfully is to drop a sump pump – wrapped in a mesh bag – down into the tea after it’s done, attach a hose to it, and spray from there.
I think this is a great idea for a small garden, but haven’t tried it. Sump pumps work pretty fast, so you’d need to be ready to shoot the tea quickly, and then ready to turn the pump off so it doesn’t burn out.
For application, the rule of thumb is 5 gallons per acre for each 6 feet in plant height. So if you have an acre of plants that are 12 feet tall, you would need 10 gallons of tea.
But most of us are just doing our backyards, so 5 gallons will be plenty. It’s impossible to over apply it, so even if you only have 500 square feet, feel free to spray the whole thing out there.
I recommend using compost tea at least two times per year. I tend to go with three times, but you might make this your main thing and apply it monthly, and that would certainly be wonderful.
Free $25 Bonus When You Buy Today
When you buy one of these brewers, you get enrolled in my online Compost Tea course.
It’s an introductory course, a nice little bit of info on compost tea and how to get the most out of the 5 gallon KIS compost tea brewers.
My main goal is to show you how to make good tea and how to apply it.
The course includes 11 videos totaling about 50 minutes.
I go into more detail about ordering on the main page, but here are a few quick things I’d like to mention:
- If you have a question about this product, leave it in the comment section at the bottom of of this page and I'll try to respond within a few hours.
- Shipping is $10 if your order is $25 or less, $15 if your order is $25-$50, $20 if your order is $50-$100, and $25 if your order is more than $100 (AK and HI add $10)
- Dry fertilizers and compost tea brewers ship for free, separately with USPS instead of UPS, so they will arrive on their own maybe a day or 2 apart from my other products.
- I ship in the U.S. only. Products ordered by 2pm will ship same day. After that they ship next day. Weekend orders ship Monday.
- All of my products have a 1 year 100% money-back guarantee.
- With every order, I send $1 to Organics 4 Orphans and other similar organizations. O4O is working with the world’s poor to help them grow organic, highly nutritious, highly medicinal food for themselves, and then use the surplus food to generate income for themselves as well as feeding the orphans in their communities. My hope this year is to again send $1500US, which is enough to start projects in 25 new communities!
In summary, the tea from this compost tea brewer:
- Provides these main benefits: improved plant growth and nutrition, better soil structure/water-holding capacity/nutrient retention, decreased disease.
- Increases the diversity and number of highly beneficial microorganisms in your soil and on your plants.
- Is proven to be a high quality actively aerated tea, verified by Soil Food Web lab testing.
Each brewer comes with 3 complete brew kits, and you can optionally pick up more kits if you plan to do a lot of brewing.
As a free bonus when you order today, I’ll also enroll you in my online Compost Tea course.
Just choose your brewer and click ‘Add To Cart’ up above!