How to Harvest a Soggy Wet Worm Bin?

One of the most common concerns of willing worm workers using one of my worm bins  is that the vermicompost gets soggy wet.  When it comes time to harvest the bin by screening through a 4 mesh sieve the vermicompost is too wet to screen.

I am posting the follow email string between myself and one of my willing worm workers who had this concern and after following the posted instructions had a successful harvest.  I am posting this to share the instructions more broadly.

From Jim to me:

Hope all is well.

A quick worm question. My worm mixture is always quite wet, almost soggy, and seems excessively wet to me. Nevertheless, the worms are prospering. I try adding more newspaper on top, but that only helps some.

Otherwise, it's all proceeding fine.

My reply to Jim:

Hi Jim,

Good to hear from you -- thanks for the update.  And here is my not so quick answer to your quick question.

Wet, soggy worm bins are common but not recommended.  The bottom of the bin is probably full of water because the dry paper we put in to start has become saturated long ago.  Probably at about 3 to 4 months (June -- July) -- and needs to be replaced.  Don't dump your bin because the bottom will stink because it has gone anaerobic. Also, the leachate will saturate your worm castings leaving you a muddy mess.

Worms don't seem to mind when the worm bins get soggy wet unless they can't breathe.  They can't live in an anaerobic environment so eventually your worm bin will be too wet even for the worms and they will try to leave.  When that happens they will crawl out of the bin onto your floor.  Since you didn't mention this that means the bins haven't got to that point yet.

Here are a few suggestions on how to dry out and harvest your bins: 

Get yourself a bag of peat moss or something similar.  It needs to be dry and of plant origin -- many possibilities.  It needs to have the capacity to absorb lots of water.  I use compost from my compost pile that has been thoroughly dried out and screened through a 4 mesh sieve.

Set up outside a large bin capable of holding twice the capacity of one of your worm bins with room to spare.  I use a 23 gallon tote.  When you are done adding dry material to your vermiculture, you will have twice the volume you started with.

Put two gallons of dry material into the large bin and then add two gallons of your wet vermicompost to it.  (Dig the wet vermicompost out of your worm bin from the top.)  Mix the 4 gallons of material by hand -- I pick up large handfuls of the mixture and rub my hands together to do this mixing.  Once thoroughly mixed, do the squeeze test on the mixture to determine if the mixture is still too wet or too dry.  Correct the ratio of wet vermicompost to dry material based on the squeeze test and then repeat step one with new mix ratio and repeat until your worm bin is empty (down to the newspaper base.)

Now it is safe to dump your worm bin into another container -- it probably has standing water (leachate) in the bottom which will smell awful.  Get rid of it by dumping on your lawn or compost pile. Put the soaked newspaper base on your compost pile.  It can also be stored and used as new bedding.

In the large container you will now have more volume of vermicompost than will fit in your worm bin so you will need a second one temporarily.  

Now you need to put all the vermicompost back into your worms bins and wait 2 to 3 weeks for the worms to "turn" the mixture into worm castings.

If you have done this correctly this mixture will be ready to screen through a 4 mesh screen in about 3 weeks.  What is rejected from the 4 mesh screen will all fit back in one worm bin.

This is Jim’s reply after following the posted instructions above:

Just wanted to say I followed your instructions and had a splendid harvest this past weekend! All issues were solved, I've learned some things, and I'm starting anew. Thank you very much!!!

Wishing you and yours a bountiful and happy Thanksgiving!

Best Regards,

Jim