To get the answer we need a basic understanding of how composting actually works.
Composting is actually trying to stabilize unstable organic matter and storing the nutrients for immediate or future use.
Usually in nature, organic matter is decomposed in thin layers such as leaves in the woods or the grass clippings in your lawn. Being the layer is thin, the organic matter is penetrable by oxygen and aerobic organisms come to play. These are the good guys hence usually a balanced compost for the environment.
When we compost, with or without worms, we tend to pile up the organic matter which makes it difficult for oxygen to penetrate hence anaerobic organisms take over. Yes these are the bad guys. Anaerobic organisms are what take over a landfill, hence why they must be lined to prevent harmful runoff to protect surrounding soil and water sources!
When we manage decomposition, such as a worm bin or worm farm, decomposition takes place in three stages for the most active microorganisms.
Phsychrophilic bacteria begins to process at temperatures below 70 degrees Fahrenheit
Mesophilic bacteria, the fastest decomposers process between 70 to 100 degrees Fahrenheit
Thermophilic bacteria come into play at temperatures above 100 degrees Fahrenheit
When managing decomposition, we pay attention to the carbon (newspaper, cardboard…) to nitrogen (vegetable scraps, grass clippings…) ratio as well as moisture and oxygen.
Composting with worms is a more controlled method of basic composting as well as speeds up the process. You maintain a constant temperature which enables the most active bacteria, Mesophilic to take over. Worms move through the organic matter helping to aerate the decaying matter as well as making smaller particles of the decaying matter, hence leaving more surface area for beneficial microbes to work on.
If the moisture content gets to high, usually above 80%, the decaying matter becomes compacted, the same way the landfill does. This is when the worm bin can begin to change over to those nasty anaerobic organisms which can be harmful to your worms and even begin killing them off.
Once the moisture content begins to rise even more, the decaying matter releases a liquid called leachate. You will see many websites refer to this as worm tea, which it is not!
Worm tea is derived by brewing worm castings which are full of aerobic microorganisms. This process is done by aerating the worm castings, water and unsulphured molasses for approximately 48 hours in order to explode the aerobic microbe population.
Leachate is usually the opposite, full of anaerobic organisms.
If you are getting a little leachate from your worm farm or worm bin, try adding several inches of dry shredded newspaper on top and place the lid on it. This will absorb a little of the moisture. If you are getting a lot of leachate, it might be time to remake the bedding for your friends!
Now that you understand the process you can probably understand why I have an issue with a few things.
First, all the websites selling worm farms with the little spigot on the bottom which they advertise as a worm tea dispenser, when in reality it is leachate which can be harmful to your worms and plants. Put it this way, it is not doing your worms or plants any good if you are getting leachate from your worm farm.
Secondly, there are many websites as well as listings on EBay offering bottled worm tea and bagged worm castings in resealable plastic bags. As you might realize by now, cutting off the oxygen in either of these two sealed products kills off the aerobic microbes and produces anaerobic microbes. So in reality, you are spending your hard earned money on something which can be detrimental to your plants.
So to answer a number of emails I receive every week, this is why Organic Worm Farm does not sell the worm farms with the little spigot on the bottom, bottled worm tea or worm castings in resealable bags. They only offer worm castings and worm tea bags which are shipped in breathable bags via Priority Mail since you are dealing with live microbes.
Hope this helps you understand the basics a little better and why it is important to avoid leachate from draining out of your bin.
Bruce Galle
Also known as “The Worm Expert“ writes informative articles to assist others raising worms. For information regarding ordering an array of red worms, worm castings and worm food visit Organic Worm Farm.
Bruce, great article. If I may take issue with your statement, “worm tea and bagged worm castings in resealable plastic bags. As you might realize by now, cutting off the oxygen in either of these two sealed products kills off the aerobic microbes and produces anaerobic microbes.”
I thought the same thing until recently. I was at a show and found a scientist that raises bacteria for all kinds of uses. I asked him that question. He told me that it is not true. Here is why. Bacteria has the ability to hibernate. It creates a shell like outer protective layer. As soon as conditions are right they come alive again.
Think of pills we take. They are full of bacteria. They are smashed, crushed and pulverized then punched into a pill. The pill is then coated with something to keep air and moisture out. But these little guys make it fine.
Now, I am not the expert but he was and my guess is you, like me were making some assumptions that are without foundation.
I also asked a company representative from Black Cow about packaging and air supply for our worm castings. He again asked some scientists and this is what he conveyed to me. They use bags with tiny holes to prevent moisture build up and in some cases the compost will continue to decompose at very small rates but enough that over time would cause the bag to swell. To their knowledge, even though their compost contains bacteria, they don’t have holes in the bag for that purpose.
About Teas; According to Dr. Ceil Edwards of OSU. Compost teas need both aeration and higher temperatures to maximize bacteria growth.
Great articles, keep me posted. I hope you don’t mind the feedback.
Barry
NaturesOwnOrganics
Barry,
Thanks for your comments.
While it is true that some bacteria can basically “hibernate” when dried out. For example, if you took some cow manure which has been recently dried out by the sun but not heated. You could place it in a plastic sealed bag for a while, reopen it, add some water and it will then again heat up and have some microbes available until they regrow. Again this is if dried out first and you do lose a number of bacteria during the drying process
As you were told, “They use bags with tiny holes to prevent moisture build up…”. If moisture can go through the little holes, then so can air with oxygen
If the moisture continues to grow, the worm castings become more packed, the oxygen becomes depleted,… again turning it to anaerobic!
Here is the definition of aerobic: In biology, a descriptive term for organisms that require the presence of oxygen to live.
Anaerobic is the opposite, organisms that do not require oxygen to survive, hence the anaerobic can survive in a sealed bag or bottle however aerobic cannot!
Just for example, take some worm tea and place it in a sealed bottle. HINT: keep it outside in case it blows! Let it sit for a couple weeks and then open it. Believe me the smell is not pleasant.
True the higher temperature to process worm tea does help, however most folks do not have a kettle to heat it and believe me you would not want to do it in your kitchen… it does smell and will permeate. However, if brewing at room temperature, you will still have more aerobic microbes than you know what to do with. You are simply taking the microbes available in the worm castings, giving them some food (unsulphured molasses), and giving them enough oxygen to explode.
Actually to make our worm tea I do not use an aerator which simply pumps air which is only 21% oxygen, but rather pump it with 95% pure oxygen. This basically puts the microbes on steroids!
Thanks And Have A Great Day!
Bruce
Hello,
I’d be curious if regadless how you obtain the liquid from your worm pile, can your airate it? I read an article that suggested to have an aquarium air pump. I bought one to make compost tea, but I assume it would do the same with a worm tea over time. This stuff is highly nutritious and would be a waste to simply dump it.
Thoughts?
Zoltan,
Hello and welcome!
You can use the worm castings to brew your worm tea. I use more than others opt for but take about 10oz of worm castings and place in a five gallon bucket with “chlorine free” water. Place two teaspoons of unsulphured molasses and stir gently. Aerate for 24 to 48 hours. The worm tea is best used right away since once you stop aerating the aerobic microbes will begin to die off
The molasses is basically food for the microbes to feed on while they are multiplying.
Do not try aerating the leachate. Leachate should be poured down a drain which is connected to a sewage company has they handle anaerobic bacteria on a daily basis. Do not throw in your yard or where it can leak into a water supply.
Hope this helps,
Bruce
Bruce,
Thanks for the feedback.
I have a question. Are there any clues (visual, odor, etc.) that tells the difference between aerobic and anearobic teas? I wonder if that’s even possible to distinguish.
Zoltan,
Worm tea which is brewed from worm castings will not have an odor unless you add to much molasses which remains, then it will have a little smell of molasses. Worm tea should look much like the ice tea you make at home.
Leachate, not always, will be cloudier and most likely will have some odor to it. I recommend not chancing it if you are getting leachate.
No matter what, if you are getting leachate from a worm bin or worm farm it is to wet and the percentage of moisture needs to be reduced.
Worms do drown! Ever see a worm in a puddle outside after the rain? To much water to air ratio will kill off your worms.
Bruce
Bruce,
Thanks again for your insight.
I researched this subject a little bit further, and some sourcessuggest to dilute any liquid that comes out from your worm bin might benefit your plants anyway. There is no question about the superior value of a matured vermicompost or the tea made oout of that, however.
Why in your view is leachate so toxic? Where is my logic incorrect when I think that aerating leachate would invite the “good guys” and chase away the “bad guys”?
Zoltan,
I am going to try to break this down without going into a scientific mode so as easier to understand
First off vermicompost is not used to make worm tea but rather worm castings. Vermicompost is a mixture of partially decomposed matter and worm castings together. If used to make worm tea you would end up with a muddy mixture.
It’s not in my view why Leachate can be so toxic but rather the facts of nature
Anaerobic bacteria are associated with illnesses humans would associate with getting from swamps, deep cold water lakes… This is why I made mention of disposing only through sewage system that goes to a waste water treatment as the chemicals such as chloride will kill them.
There are three basic types of anaerobic microbes.
Obligate anaerobes – which will eventually die when oxygen is introduced. Basically you would need to let your vermicompost sit in a thin pile or turn weekly for approximately six months to a year in order to kill off the anaerobes.
Aerotolerant organisms – will continue to grow when introduced to oxygen however will not reproduce. Hence aerating will not get rid of them.
Facultative anaerobes – will continue to grow and reproduce when introduced to oxygen. Again aerating will not kill them off and they can continue to grow in population size.
Now unless you have your own laboratory to run tests, you will not know for sure which type(s) of anaerobic microbes you are dealing with.
Anaerobic microbes decompose matter differently. They do not consume nitrogen; hence your vermicompost most likely from the start will be high in nitrogen which can burn plant roots… Now excess nitrogen will basically convert to ammonias which again will be harmful to your plants!
Being Leachate is developed from wet compacted compost, most likely it will be full of anaerobes.
In nature, worms come to the ground surface when it rains and the ground becomes saturated. This is because the moisture to oxygen ratio is not to their liking and can kill them. The same occurs in your worm bin or worm farm when the compost begins to compact and full of moisture. The oxygen cannot penetrate the compost and anaerobes begin to replace the good aerobes.
Have a good weekend,
Bruce
That was very educational. Thanks for the time and effort, and not least the information.
Zoltan,
Your Welcome!
Bruce
Good reading for a relative newcomer (me). My personal experience is based on having 2 C-O-W (stacked tray systems) for 3 months. I think the tap is great, as it allows the leachate out rather than just having it sit inside and stagnate. As it’s pretty hot here at present (south Australia) – just had 5 days over 35 degrees C (95 F), the worms go looking for the cool spot, and the bottom collector tray is probably a good place for them, and they don’t drown as the tap is always open.
There are 2 reasons for the leachate in my systems. Firstly, I chop all the feed in a food processor, it’s spoiling them I know, but I am looking to boost the capacity of the farm. This tends to release the water in the vegetables right away, compared to them slowly drying out if left intact.
Secondly, to cope with the heat, I have left the normal lid off and placed fly screen over the top to allow air movement and keep bugs out. I then spray the top hessian covering a few times a day to keep it moist so the evaporation can help cool the farm.
I think it’s mainly the processed food causing the leachate, as I have only sprayed during the hot spells, but tend to have leachate all the time.
I recently added a new bottom tray to each system filled with soaked/squeezed shredded carboard and newspaper to see if it will stop the worms going to the very bottom – but it hasn’t. It also hasn’t really affected the flow of leachate apart from the first day as it was soaking some up.
So, for me, the tap is a good thing.
However, my experience is also that leachate doesn’t seem to achieve much in the garden. I have applied it to patches of lawn both full strength and diluted with no noticeable effect, compared to where the lawn went yellow where I pee’d on it (coff) or green where the dog has done the same. The affect might vary with different plants.
I figure my leachate is usually fairly “fresh”, no smell, drips into an open bucket etc, so I often tip it back through the bin to both help it stay cool and put microbes onto the food.
Again, this is just based on the experience of a newcomer, but it’s a vote for a tap from me!
Welcome to the blog
A thought came to mind while reading your comment. If you are adding a lot of food scraps, even when pulverized, this would put off a lot of heat and most likely why your bin is running so hot. Try adding more layers of browns, basically shredded newspaper, cardboard… This should help to cool the bin down after a little while being you are hot over there currently… Can you send some of the heat to the US?
Also after you have used the blender to spoil the worms
you can add a filler such as some peat moss to thicken the mixture so as not to create so much leachate.
Just some food for thought!
Bruce
Typically I spread the days offerings over 1/4 of the bin – for each bin, so it’s not that thick a layer. They usually ignore it for about 2 days which I figured was allowing the microbes to get involved. Yet today I noticed that in one bin they are starting into yesterdays food, and in the other bin, they are quite heavily into it.
They actually got 2 lots yesterday, as after I had done the regular houise scraps (450 gm) I noticed a small water melon growing in the garden had split, so gave the blender more exercise. As this was very watery, I added some egg carton and some coir into the blender to dry it out. That feed came to another 1250 gm, so 1750 gm (3.86 lbs) in total for the day.
It was 37 degrees Celsius (98.5 F) again today, so I had the screens on, but being busy only sprayed the bins a couple of times, though when I checked all the layers at tea time, it was a very busy place all through out.
So yea, I often decant out excess moisture, as I occasionally add some leachate to aid the blender, and/or I add some cardboard or coir as well.
I must say, it’s really satisfying having a look and seeing worms everywhere all having a good time!
More info, eleven days ago after doing some more reading, I got out a spare tray, put a layer of cardboard on the bottom, then added a bunch of shredded newspaper, shredded cardboard and coir, which had all been soaked in my first brew of Aerated Worm Tea (another proud moment). I put it below my active tray (that bin was still on it’s first tray) and within a day worms were getting into it a lot, so I then did another tray pretty much the same for the 2nd bin.
This bin already was on it’s 2nd tray, so I inserted the new one between the bottom castings layer and the working tray. It isn’t as busy as the other bin, though I suspect that is because it is not as full, so isn’t touching the upper layer in as many places. Also, the worm tea mix may not have worked quite as well.
When I looked tonight, the first bin’s new layer looked to be very much converted to castings, I completely turned it all over and there were worms everywhere, and it almost appeared that most of the paper/cardboard was gone! While I was at it, I effectively destroyed the cardboard bottom, as I felt it wasn’t stopping the few worms that wanted to go down – they went around the outer edge, but it did mean they had a hard time getting back if they climbed either the centre hill or the leg towers.
I hope nobody is bored yet, I am enjoying sharing what I have learnt.
It’s always good to hear from others about their own worm farming adventures
Bruce
I have been reading your comments on worm leachate. I’m confused, if leachate is bad for plants and cannot be bottled, what are companys like fox farms using in there bottled mixtures, which say they have worm castings in them. Thank you
Jerrod
I do not know what they are using. I can tell you this. First, worm tea and leachate are two different things. If you bottle worm tea, you cut off the aerobic microbes produced in the worm castings and worm tea. You are defeating the whole purpose to generating worm castings and worm tea as a by product.
If they have worm castings in them, they are useless and might as well be omitted. Perhaps this is so they can place worm castings on the label to sell less knowledgeable people believing they are purchasing something that is really good for their soil.
Bruce
Bruce
First off, really appreciate all the info! I’m very new to worm composting and appreciate the perspective. A question though: I’m looking into worm composting due to the successes I’ve heard from others. 3 different friends (with different gardens in different, neighboring cities), have told me that they were “experimenting” with using their worm farm runoff (what I think you are describing as leachate) in their vegetable gardens, watering half their planting with runoff and the other half with plain water. In all 3 cases across all 3 different gardens, the plants watered with the runoff from the worm farm were significantly larger, healthier and more productive. Same crop, same area, sun exposure, soil, etc. – but one set was given plain tap water while the other was watered with water+worm runoff. Your science sounds very reasonable, but it’s hard to reconcile with the results they saw. Am I confusing “run off” with leachate? They had a set up with a spigot at the bottom of a stacked bin and collected the liquid that pooled in the bottom tray, which sounds to me like what you are calling the leachate. I’m confused – any help you could offer would be appreciated. Thanks!
Keerok
Let me start with perhaps a little more explanation here… as many are confused due to the false information advertised by some worm bin manufacturers and web site owners.
First there are two instances which happen when collecting leachate from the bottom of a worm bin versus collecting worm castings (vermicast, worm poop) not to be confused with worm vermicompost which is a mix of unfinished decaying material and worm castings.
When collecting fluid from the bottom of a worm bin, the liquid passes from top to bottom basically which can carry unfinished decaying material. This includes a lot of malicious bacteria, some of which is converted into beneficial bacteria which is converted by worms as they digest.
On a second note, as I mentioned earlier, you are basically setting up a swamp environment which can cause humans severe sickness and diseases. Here, water seals off oxygen and helps to compact organic matter which is not converted, hence generating anaerobic (harmful) bacteria.
Ever notice when it rains that worms come to the surface? It is commonly believed (not proven fact) that it is due to the lack of oxygen due to the soil becoming too saturated with water hence cutting off the needed oxygen ratio to water for a correct worm environment.
By using worm castings ( again not referring to vermicompost) to brew worm tea via a process of usually aerating in water for 24 to 48 hours and the assistance of a food source, i.e. unsulphurized molasses, you help to explode aerobic (beneficial) microbes. worm tea needs to be used within 24 hours of brewing and should never be placed in a sealed bottle or container over an extended period of time.
I am not stating that every batch of leachate will harm you or your plants, however extreme caution needs to be adhered to. I have heard numerous horror stories of people using leachate on their plants, some of which have had damaged their plants overnight.
If you ask any professional, reputable worm farmer, they will inform you that if you get liquid coming out of your worm bin, it is too wet. The only holes on the bottom of our worm bins are for aeration.
I honestly believe if the tests you mention were ran with leachate compared to true worm tea rather than plain water, you would see a much better result with the worm tea
Hope this helps.
Bruce