DIY kitchen waste compost "appliance"

Alright, it is probably time for me to make a post about this project and stop hijacking the conversation in this thread: https://permies.com/t/240118/composting/Bokashi-composting-Reencle-coming-today

For a whole array of reasons from busyness of life and physical health issues to emotional traumas, it has been hard to get my family in board with composting our kitchen waste... but I also don't want to give up and either resign to throwing it all in the trash or having it tend to pile up longer than it should on the countertop and start smelling and growing mold (or somehow throwing most of it away, but still having moldy piles collecting around the kitchen, which is where the past emotional traumas have tended to leave us...).

So I'm still trying to find different solutions. But I'm also not incredibly excited about spending (several?) hundreds of dollars on a new appliance specifically for this purpose.  

To be quite honest, the issue is big enough (especially since it does relate to emotional traumas in our case) that I'm not taking the purchase of a commercial option completely off the table, but I think I want to explore some other ideas/options first.

Looking at what the main commercial options out there do, the majority of them seem to mostly just dehydrated the waste and then kind of break it up into something that looks similar to a compost or soil, but is still really just powdered kitchen waste that needs to be composted.

That's not the end of the world - it's not a moldy, slimy, stinky mess and I could work with that. But I like that one option in particular, the Reencle (no affiliation... though perhaps I should sign up as an affiliate lol 🤔) uses a bokashi style fermentation process to break down the food waste as it goes.



Ultimately though, all that any of these devices are really doing is applying a small amount of heat and gradually churning the waste to break it up, and in the case of the Reencle to mix the microbes thoroughly into it.  Sure, they've got fancy computers to time everything, sense temperatures, humidity, weight(?), etc and control the cycles with that information and charcoal and other filters to reduce the smell (no reason I can't add a charcoal filter as well). But low heat and slow mixing is "all" that is happening from a functional standpoint to get from kitchen scraps to brown powder.

I thought through quite a few different options - many of which I think are valid - for how to accomplish this for a lower price tag.  First I was wondering about an easy way to do something like this in a crockpot. Then I started thinking about a bread maker/machine (which I kept coming back to, especially after realizing that so many of them actually have yogurt and other fermentation options as well as options for setting up your own functions with custom times, temps, mixing settings, etc...). I discovered automatic stir fryers, as well as a bunch of other appliances I had not ever really thought about before... ultimately, so many of them are all just different ways of mixing things and applying heat, so they seem like they could be valid options. Some would require more modification than others either to make sure they didn't get too hot or to make sure the mixing was not too wild.

Last night, I was looking at a blender we had been given a while back trying to take it apart and see if I could easily separate the motor to gear it down to a slower speed. Ultimately, that was going to be fairly difficult to do, at least on that specific blender, though still an option.

But afterwards, I remembered that I also had a spare drill that I'd won as part of a lot in an auction a while back and could potentially rig that up.

In addition, I have an old coffee pot that became unusable as a coffee pot after enough mineral buildup, but I had hung onto in the hopes that one day I might rebuild it in a way where it could actually be cleaned out manually (vinegar wasn't cutting it). Well, mineral buildup didn't stop the hotplate from working, so I decided to scavenge that for the project along with an old popcorn tin and see if I could get a very rough prototype going...

So this morning, I took the base off the coffee pot and made a custom mixing bit for the drill, put a pretty decent dose of some DIY bokashi starter inoculant we had made quite a while ago in with some food scraps, and I am giving this very rough prototype a shot to see how well (or poorly) it performs the job.  

I definitely have some ideas already of how to improve the design, but initially I wanted to just get *something* started and see how it works.

I was trying to upload a couple of pictures, but our ISP really sucks and our Internet has been down at the house for like 3 weeks now and the service on my phone is too choppy to upload the images lol.

Hopefully once I can get connected on something more stable I can upload some images.

John said, put a pretty decent dose of some DIY bokashi starter inoculant we had made quite a while ago in with some food scraps, and I am giving this very rough prototype a shot to see how well (or poorly) it performs the job.

Thank you for sharing your thoughts.

How has this turned out?

I quit trying to get others on board and just do the things I want to do.

Cool project!
I think an old  stand mixer,with the egg beater blades could be perfect for this.
The built in speed control is very appropriate for this kind of project.
Ive kept my old hand held version of the stand mixer in the hopes that I can drive a rock/parts tumbler with it.

Unfortunately, our home Internet is still down (the repairman finally came out after 3 weeks of no progress whatsoever, but as nice as he was he seemed to have incredibly limited support from the company itself to actually fix much unfortunately, so we still have no landline and our Internet is competitive with the 28k dialup we had here a couple decades ago... but that's all a separate mess) so uploading pictures is still difficult. But in the meantime, here are some thoughts I've got about the project so far:



First, I'm impressed by how much of a difference just a little bit of warmth and a little mixing makes to the process compared to just leaving the stuff to sit.


Second, the drill that I'm mixing with is not currently anchored to anything and neither is the old popcorn tin that the waste goes into. This makes it very easy for things to get briefly bound up and the popcorn tin to want to start spinning wildly if I don't have it held down already.

Third, while the smell is not all that bad (certainly not what you might expect considering what is going on inside the tin - and at an accelerated rate) even without filtration, it would definitely benefit from some activated carbon - either as an air filtration setup or I suspect simply adding it to the mix directly would also do the trick.  I've got both some activated carbon from an old aquarium my mom used to keep which I plan to try out as well as just some biochar.

Fourth, I don't currently have the system enclosed/insulated to hold the heat in and I imagine it would be much more efficient if I did. I have an old cooler I scavenged from someone else's discards pile I have been considering using for this, but it also occurs to me that the more lids I add to it the more complicated accessing the drill and even just attaching the drill to the shaft of the mixing tool will be.


With how much I have going on in life right now, I am questioning how far I will actually be able to take this project towards its potential, but even just throwing a bunch of random "junk" together I have been somewhat impressed with how much it did to speed up the decomposition process in a less slimy mucky way.



I agree that a kitchen mixer with adjustable speeds could work quite well for something like this.

Make a rocket mass composter and people on here will squee themselves.

John Warren wrote:Fourth, I don't currently have the system enclosed/insulated to hold the heat in and I imagine it would be much more efficient if I did. I have an old cooler I scavenged from someone else's discards pile I have been considering using for this, but it also occurs to me that the more lids I add to it the more complicated accessing the drill and even just attaching the drill to the shaft of the mixing tool will be.

If you could make the cooler the container too....Mount the drill through the lid of the cooler so it doesn't whip around. You'd probably need to round the corners off inside somehow so you don't get dead spots. Hmm, an inner heated container? From the outside make it look just like a fridge for cosmetics. Do you need vent holes for air exchange? I would think so, although that would negate some of the insulation of course.
Is this a batch process, would you need two - one loading and one cooking?

My techniques are pretty lazy, we just have a large stainless steel mixing bowl on the counter that generally gets emptied every day. Sometimes less often. If we're cooking with onions / garlic then we'll empty it within hours to keep the smell down. But the compost heap isn't that far and I can always use the exercise of walking around a bit. Dump it in, rinse the bowl, ready for more. Easy peasy.