Hi Harry, IIRC MendoPete once told me to look for about 5:1 reduction though it might have even been higher than that and more like 10:1. I too am interested in this question and have to wonder if the inputs dont have a great deal to do with the answer.

You dont have a zone listed but for some reason I am thinking I saw a post from you about Canada, if thats the case then large outdoor worming might be out of the question but thats the direction I am looking here to overcome the reduction with volume and try amassing those mountains of black gold.

The inputs have a lot to do with it. I have read, back in the days when people on the forums were quoting Clive Edwards, that horse manure reduces down to 1/4 of the original volume. (Yes, I think that came from Clive Edwards.) Shredded cardboard and kitchen scraps would reduce even more than that.

Apparently my recollection machine was out of whack. Just saw a post from you Harry that mention PacNW Z8 which is probably not much different than Pete so the outdoor piles of HM Carpet Beds could be an option for making loads of VC if you have the space for them.

We are Z8 here also but quite a lot different in terms of weather as we are quite dry with few storms through the winter. Average lows and maximum lows are different animals when considering ground temperature.

Hey Harry, came across this and thought of your thread here. Seems these guys are on the 5:1 to 10:1 bandwagon. I also think as mentioned above just what the inputs are is going to make a big difference especially if the majority of feed is of a single origin.

Here is a link that might be useful: Input/Output

Thanks Nevex and sbryce for the reply. I think you're right about the output being determined by the type of feed. Kitchen scraps like fruits and veggies are probably very high in water content whereas something like horse manure is much higher in carbon/humus content which I'm sure goes in pretty much the same as it comes out.(of the worms)
Just imagine 2 piles of feed stock the same size - one of strictly fruits and veggies, the other a pile of horse manure. Left to the elements for a few months, I'm sure the manure pile would be much larger the the fruit/veggie pile because of its higher amount of fiber(i.e grass, hat etc).

This is an interesting topic that is hard to find a clear answer for. Many variables exist, such as feedstock, bin type, time allowed.

Vermicompost vrs. pure castings: Worms will continue to process VC into castings until it is nearly 'pure' dense casts. It takes a long time, depending on feedstocks. Most vermicomposters do not allow finishing of material, but use the unfinished VC. I have had some VC (I thought was finished casts) sitting in a tote for the past 18 months. I found plenty of worms in there and the material had 'shrunk' some more. Much depends on the amount of time.

Comparing volume in vrs. out it is nearly impossible due to variety of food and bedding. How much of the bedding is air? Is the gallon of bedding fluffy and full of air, or compressed like peat? Is the horse manure fully fresh, aged, or composted? Do you process the food first? Are you measuring volume out after drying and sifting (more volume and less weight) or in its dense fresh state. All effect volume comparisons.

Weight in vrs weight out is also tricky. Most of the weight is water, which is evaporated or consumed by worms. My freshly harvested castings weigh about 7lbs/gallon, but after drying and sifting they weigh about 5-6lbs/gallon

. I GUESS it takes about 40lbs or 10 gallons of fresh horse manure for me to create a gallon of casts. I have not even considered weighing or measuring inputs vrs. output. It would be nearly impossible unless done in a highly controlled scientific environment. I have read that output is 10-25% of imput. If Clive Edwards says 25%, then that is a good rule of thumb. Dr. Edwards is highly respected and considered one of the worlds leading experts in vermiculture.

Hope this helps some.

Good luck and happy wormin'

Pete

In my old house, I had several trees, enough to fill four compost bins to overflowing with leaves every year. When the next fall came, the compost filled only one of the bins. So just thermophilic composting reduced the OM to less than 25% of what I started with by volume. Worms would have broken it down even farther.

When I had my flow through bin, one problem I had was that no matter how much I fed it, it never got to the magical 20 inch deep mark where I intended to start harvesting.

This isn't great news at my new home that has terrible soil, and no sizable trees anywhere in the neighborhood. It will take decades to produce enough VC to cover the yard with several inches of VC.

Interesting topic because for most vermifolks the end result of the work being done is what we are after. The tillage is a secondary benefit for those who garden in their worm beds.

The 10 to 25% output vs input sounds to be a fairly well agreed upon number. Equating this to worms and using Petes 7lbs a gallon for fresh castings one would need 28 to 70lbs of worms receiving the same daily in fresh input to get a gallon a day VC harvest. That is 1.8 cu yd a year out for 7 to 18 yds a year of input.

Sorry about the numbers, it is how I visualize things. Trying to imagine how much of a walking windrow I would need and how much feedstock would be required to fuel it. Since the end desired result is VC and the input is being reduced as it is added the limiting factor would be working room for the inhabitants. Calling a midrange number of 50 lbs using the above numbers a 2.5 x 20' windrow should accommodate them well.

Nearly two yds of castings annually from one system of this size sounds like a pretty fair return. A cu yd BTW is about 200 gallons.

Many thanks to you fellow whacky wormers for the input/output insight. Imagine all that awesome black gold we would have if output was = to input!!!! Guess we'll have to keep working on that one.
later,
Harry

Here is another interesting thing I often think about:
What are the conditions which entice a worm cocoon to hatch vs. remaining in a dormant state(say under freezing conditions)?
Last year I had a rather makeshift bin of worms in some used potting soil and I tried adding some bokashi food scraps. Well for about a week I didn't see much worm activity around the bokashi, then soon afterwords there was hundreds of small to very small worms all over it. Seemed kind of weird, where were all the more mature worms? For the rest of the summer season it seemed like there were only small worms, very few were getting larger like I would have expected!
Any thoughts?

Yes, but we try not to mention it because it makes people sad to know these worms will never grow. I always feel mean so I won't say it. Somebody else's turn this time. :-)

""only small worms"" How small is small? (just to have a better understanding)

otis11,
I would say the worms were only about an inch long and skinny but very active and healthy looking. So if they were healthy, why didn't they seem to grow larger over the summer season? I don't know if there are any worms in there now since I haven't added food since Sept. (the bin is half of a 45gal. plastic barrel - about 3/4 full of used potting soil). I'd put some food in to see if any worms show themselves but a squirrel or something has chewed access around the lid and keeps digging around. Don't know if it's looking for worms or the food in there from earlier in the year.
Harry

Harry

Ive been doing mine about the same length of time as you and I too still do some experimenting with foods . When I get scrap foods I keep mine in ziplock bags until Im ready to juice the. Besides the norms Im not opposed to putting in pasta and pancakes and other such foods , all this goes in the ziplock grab bags, then it all goes together when its juiced so figure wont hurt much. I also like to give them watermelon rinds and I cut those up and freese them to ready to give them a treat.