Restaurant Food Waste Vermicomposting

Back in May, shortly after starting my own composting business, I decided to see if I could track down a local source of ‘food’ for my worms. While we certainly do produce a fair amount of compostable food waste ourselves, I knew it wouldn’t be nearly enough to feed the worm herd I planned on growing.

I decided to approach the owner of a very popular restaurant in town, At the Crossroads Family Restaurant (usually referred to simply as ‘Crossroads’) to see if he might agree to part with some of his coffee grounds and egg carton cardboard. Little did I know I’d be opening a much bigger ‘can of worms’ (literally and figuratively)! As it turned out, the owner – Anton Heimpel – was very open to the idea, and seemed keen to provide me with plenty of other materials as well. So we sat down for a meeting hammer out all the preliminary details.

Fast forward two months (from my initial contact), and the project is still going strong. The funny irony is that I still have yet to see a single batch of coffee grounds (the material I originally inquired them about).

I’m certainly not complaining. Crossroads provides me with literally hundreds of pounds of vegetable and fruit waste per week. Needless to say, my worms are extremely well-fed!

The project has been an eye-opening experience to say the least. It has been a major commitment in terms of both time and energy. I pick up buckets (like the one shown above) 6 days a week, unless other arrangements have been made, then chop up the material by hand before using it in various composting systems.

I’ll be honest, for the first couple of weeks I was wondering what on earth I had gotten myself into (and I still have my moments – haha). Aside from the fact that it felt like I was spending all my time handling the wastes, I also didn’t really have the necessary systems in place to utilize all the materials – at least not in a ‘neighbour-friendly’ manner! Speaking of which, given my close proximity to neighbours and the fact that my backyard is so visible, I’ve had to work extra hard to keep things looking and (even more importantly) smelling ok! It has meant that a lot more time needs to be dedicated to waste handling, BUT it has also been a great learning experience. I’ve discovered some cool composting techniques, and I’ve also learned what NOT to do with food waste!

Here’s an example of the latter category…

Something I tested out early on was the use of temporary storage vessels for precomposting. These are basically big Rubbermaid tubs with many, many holes drilled in them. I chopped up the food waste, mixed in some soil (to kickstart microbial action), then dumped it in the bins, which were lined with cardboard. I figured that with all the air holes, and regular stirring, the materials would remain relatively odour-free as they started to decompose.

I figured wrong!

I’m sure this could work ok for some materials, especially if lots of shredded cardboard was mixed in as well, but I receive lots of brocolli and turnip waste – both of which have the tendency to get pretty skunky as they break down. It also certainly didn’t help that I ended up leaving one of this bins for quite a few days in my shed without ANY mixing of the materials at all! You know it’s pretty bad when you can actually smell a powerful rotting odour coming from a closed shed – and you can’t even imagine how bad it smelled when I opened the door.

Even my trusty backyard composter couldn’t help me out with the never-ending waste stream. I tried adding materials to it early on, but it just ended up reeking! So much so, that all the contents ended up being dumped into another system I’ll be describing in a minute.

Thankfully, I finally started to hit upon methods that worked – and worked well! Most of them center around the idea of ‘pit composting’ – basically you dig a hole, you dump in the waste and you cover it up! Relatively easy – and completely odour-free. For the first few weeks I felt more like a squirrel than a ‘compost guy’, but the important thing is that I was able to handle all the materials – and was able to create some nice pockets of slow-release fertilizer while I was at it.

In an effort to make my pits more worm-friendly, I made sure to add lots of cardboard at the bottom and a layer or two in the heap itself. I also hit upon an even better system – the vermicomposting trench (something I’ll be writing a lot more about). In fact, it was via my first trench that many of my methods-gone-wrong were rectified. I put a thick layer of shredded paper and cardboard down along the bottom of the trench, then basically dumped in all the nasty stuff, before covering with some soil and peat moss.

I think the real turning point in all this came about once I was able to secure a steady supply of straw for myself. Having ample amounts of c-rich bedding material on hand has made all the difference. I’ve been able to add thick layers of straw over top of my trenches, and was even able to get two backyard composters up to full capacity without too much stink!

The combination of 1) warmer temperatures, 2) having more systems in place, and of course 3) a worm herd that’s continued to grow by leaps and bounds has helped to make this a much more enjoyable experience in recent weeks. Oh, and did I mention the monstrous, healthy plants I’ve been growing as a result?

No?? Ok, well that will have to wait for another post!

Stay tuned – much more to come!

**For Even More Worm Fun, Sign Up for the RWC E-mail List!**
Previous Post

Apartment Vermicomposting – Revisted

Next Post

Reader Questions – 07-14-08


    • Kami
    • July 16, 2008

    Your success is fantastic. I hope this type of relationship between restaurant owners, (eventually) grocery stores, and wormers (is there another term? Worm caretakers…nah) can be developed in more communities.

    You may find that this winter you will be composting so much organic material that snow won’t stick to your yard! You won’t have to heat your house.

    • Bentley
    • July 16, 2008

    Thanks Kami!
    It definitely should be interesting once the cooler weather hits. I think it will actually work very well with cooler (fall) weather, simply because the temperatures in the composting materials will be closer to optimal (I suspect that the combination of microbial heating and summer heat makes temps a little on the high side) – plus, my worm herd should be much larger by then as well.

  1. such a great idea! (mmm, some pretty good people food there too! I was there once for work.)
    I was just talking to a local coffee shop about getting some grounds… they have way more than I’d be able to take on, but they said they were more than welcome to the idea of me giving them the sized bin that I could handle daily.. lol, I could likely only take about 2 ltrs a day. But I was super excited that they were open to the idea.
    how deep is the trench that you’re using? are the worms just following the yellow brick (straw) road of food? will you have to move them back to the start of the trench? I’m looking forward to hearing more!

    • Bentley
    • July 20, 2008

    Hi L. Bo Marie,
    Nice to hear from someone in the region. Your blog looks great.
    I have several trenches and they are all somewhat different in terms of depth. I made my first (and primary) one about 3 feet deep or so, but they don’t really need to be this deep – the deeper you make it, the slower the stuff at the bottom is going to decompose.

    I have worms throughout the trench, and simply add layers at the top – this way it will be more uniform through the length in terms of moisture and fertilizing potential.

    Anyway, hoping to write my post about trench composting this week!

  2. Thanks for answering! I was picturing a wave style system I think… sort of like when you move worms around a bin with directional feeding… your system makes much more sense!
    Thanks for visiting the blog… it’s just gone under some rennovations, so it’s still missing most of it’s content… *sigh* I’ll get there eventually.

    • Craig Cochran
    • August 26, 2008

    I like the idea of worm composting on a large scale. But since we typically compost to make fertile soil for organic gardening, are we simply recycling the pesticides, herbicides, and other contaminants found in food from restaurants? Unless the restaurant food was organically grown, are we poisoning ourselves through the worm castings? I really would appreciate discussion on this subject since I have a garden spot with crummy soil, and I want to build it up.

    • Paul
    • December 4, 2008

    Can’t you just throw worms in your garden?

    • Bentley
    • December 4, 2008

    You can if you want, but if they are composting worms they likely won’t stick around for long. Species used for composting are specialized for a rich, organic matter environment, such as that found in a compost heap or manure pile

    • Lee
    • March 10, 2009

    A quick note to Craig, above: I’ve been composting for about
    30 years, in 4 longterm places. So far, I’ve seen no indications
    that composting restaurant scraps (pretty much the same as
    scraps from home, but in larger amounts) caused any poisoning
    or problems. In fact, for composters out there, including our
    grand site host himself, I recommend your local grocery store
    as a source for more vegetable cuttings and throwaways. You
    can end up with two or three huge Hefty bags of goodies every
    day or so if you really want to. (I only go a few times a season
    to get more “green” materials for my Kemper Compostumbler.)
    And many many thanks for the compost-trench idea! I’ve got
    a long barrow of leaves from my kind neighbors (who don’t want
    to pay the city to haul them away), to which I add my winter
    kitchen gleanings, plus three ground-type heaps & the tumbler
    going during summers–and I love to wander out with a batch of
    potato peels or old carrots and just drop ’em in the garden any-
    place with one kick of my shovel. But the trench! I’ll be in
    composter heaven! Picture me, out there with my Mantis tiller,
    toodling along between rows, adding new trenches of goodies
    whenever I get a minute. Oh, and picture my raccoons &
    possums, digging it all right back up. Hmmm. Did you have this
    problem?? (If I could post pictures, I’d add one of my not-quite-
    pet raccoon, who comes when I call.)

    • Bentley
    • March 13, 2009

    Weird – not sure how I missed Craig’s comment there (considering I answered the one after it)! Thanks Lee for your great response, and for calling me a “grand site host”!

    Craig – that is a valid concern in theory, but there are some important things to take into consideration. Any pesticides left on the waste materials will likely be in relatively low concentrations to begin with (some crops are obviously much more of a issue than others), and the humic complexes in compost provide exceptional binding sites for these sorts of chemicals, thus immobilizing them. Worms themselves can also accumulate various nasties, such as heavy metals etc, so when it comes down to it, the actual amount of ‘poison’ that will end up in a crop grown in this compost is almost certainly going to be very negligible.

    It is obviously important to consider all this if you have plans to market your vermicompost as ‘organic’ however – in my mind, unless the produce is ALL organic to start with (and what about the bedding materials as well?) you can’t really do so.

    Anyway – just my 2 cents!

    • Kami
    • March 15, 2009

    I am not sure, but I think that organic farmers can use manure that did not come from organically raised animals. So, it is possible that use of composted veggies etc. even if they are not organic is acceptable in organic gardening. This is something that can be answered with a little research about what officially constitutes organic farming (I wish I could provide a link, but do not have one on hand).

    On the other hand, I have been reading articles about farming in India where worms are providing waste disposal as well as castings for farms. If I am remembering correctly, part of what the worms do is aid in breaking down these harmful chemicals into their natural components. To find these articles, I use Google search ‘vermicompost’ and then click on news. There are some terrific articles available about vermicomposting.

    • yoshi
    • June 30, 2009

    I am curious about the worm trench method. Did you just let the worms loose into the trench? Don’t they wander off? What about the temperature in the winter?

    • Bentley
    • June 30, 2009

    Hi Yoshi,
    The idea is to create a good composting worm habitat in the trench first (just as you would when setting up a worm bin) then inoculate with worms and/or cocoons. If set up properly, the environment inside the trench will be a LOT more appealing to these worms than the surrounding garden/lawn etc.

    Winter in my area is a down time for the trenches. The worms seem to survive subzero temperatures quite easily in the trenches (adding some leaves or straw at the end of the season would really help) and are ready to go again once spring arrives. If you wanted to keep the trench active (assuming we are talking about during a cold winter) you’d likely need to mound up a lot of organic matter (eg manure) and add a thick layer of straw or fall leaves to help keep in the warmth.

    • Ruth
    • October 31, 2009

    This site is exactly what I was looking for. I’m trying to start a composting program that uses not only uncooked vegetable and fruit peelings and cuttings, etc., but also post-cooked uneaten food. When I say food, I mean the kinds of things kids throw away from their school lunches. Is it possible to “vermiculture” left-overs? What about meat, lasagna, spaghetti sauce, hard boiled egg sandwiches–all those things that are left on the plate or in the lunch box to be thrown away. Can they be used for this?

    Bentley, thanks for your web site. It is powerful.

    • Bentley
    • November 1, 2009

    Hi Ruth,
    I would say that a small amount of meat/dairy etc would be ok – but probably not in the amounts that would almost certainly be found in a typical cafeteria waste stream. You would run the risk of creating some pretty foul conditions and potentially running the risk of attracting unwanted pests if the vermicomposting system was outdoors. I think the key would be education in a situation like this – if most of the meat/dairy/oily foods can be separated out (again, having a little shouldn’t be a problem) then you should be able to process the wastes via vermicomposting.

    You might want to track down a copy of Binet Payne’s “The Worm Cafe: Mid-Scale Vermicomposting of Lunchroom Wastes” – this should be a helpful guide for your situation.

    Hope this helps

Leave a Reply

Your email address will not be published.

Get Your Free Vermicomposting Guide!

* Join the Red Worm Composting E-Mail List Today *