One problem may be the finished concept fighting against proof-of-function. You want an in-home machine; that implies a severs size limitation. You also mention turning a pile; that seems to imply no size limitation. As for adding all the gingerbread, you should note that commercial machines that auto-compost food scraps are, in reality, relentlessly single function and grossly messy.

It also houses a chopping board with scales to encourage more food prep and stop waste at the source by reducing portion sizes.

Now that's GROSS. I would not want food prep anywhere near what is a glorified garbage bin.

yeah I think you have a nice start...but I agree with lazy_gardens the board/scale attached to the composter would be a sanitary issue. Perhaps you should look into some kind of vermicomposting machine. For one you got faster composting ability and no turning necessary. Issues include escape, moisture, and product extraction. The extraction of worms from compost is the hardest part but maybe you can find a solution. Also, some kind of attachment that shreds paper and grinds up food waste at the same time would be beneficial. A paste with small particle size would be quickly consumed by worms. If you can do that and maintain perfect environmental conditions with moisture, temperature, and light you would have a perfect machine.

I'm always skeptical of composers that require electricity. Using energy to hasten decomposition seems somewhat anti-green.

But it if you can invent a reliably un-stinky kitchen composter, I'd be interested to hear more!

Its an neat idea. Good luck.

Size is an issue.

Usually many indoor composting operations are worm based. That helps keep it smaller.

I think about the normal amount of veggie scraps that we produce in a day (one very large bowl full maybe a gallon +/-), or even a week (several bowls, 7 gallons or more?).... then I think about the amount of browns (3:1) that I need to compost them and the size becomes an issue right away. It would need to be 20 gallon size or larger... at least at my house. Its doable but seems large. It would need to be the at least the size of another appliance like a dishwasher... which could be cool.

I would encourage the vermicompost idea. If you do that, you could have a grinder built in, that you would put veggies/greens first, followed be paper/browns, and maybe a very light rinse with water, if needed (preferably no rinse, since too much moisture is a more common problem with vermicomposting). You would need some sort of collection device at the bottom for liquid that builds up at the bottom of a vermicomposting set up. Ideally, this device would have an indicator to let users know when the liquid is full. This liquid is highly beneficial as fertilizer for any plants. You need to provide plenty of air circulation (for any composting process) but might need to include exceptionally fine mesh to prevent escapees for households where these would be unacceptable.

Martha

Seven days worth of kitchen scraps just doesn't give you the volume you need to make compost, unless like stated you are going with worms. My thoughts, if I had the kitchen sink area against an outside wall, was to make some sort of chute to an outside bin, but there are other issues with that. From mostly kitchen scraps, it takes me about three to six months to completely fill my compost bin - a ten foot long length of four foot tall welded wire fencing formed into a ring. This is really a good volume necessary for successful composting. I dump my kitchen compost bucket every couple of days, collect coffee grounds from the coffee pot at work, and maybe a few weeds from the garden. Each time I dump the compost bucket, I cover with a good layer of shredded leaves. I end up with about two of these bins of usable compost each year. I really don't end up with grass clippings since I leave all those on my lawn (unless I find some in front of a house or bring it back when I take garbage to the tipping station). Lots and lots of mulching with ground up leaves from neighbors is my very best soil amendment, with compost used selectively in places where it will do the most good.

Some very interesting comments and ideas here. I'm thinking since this is an academic exercise, it doesn't necessarily have to be a perfectly marketable product. That's probably part of the exercise and I'm not saying it should be neglected. As Tom Lehrer said about the New Math (back in '68), "The important thing is to understand what you're doing, rather than to get the right answer." :-D

Firstly i would just like to thank all of you for taking the time to respond to my post and there are some very interesting points here.

To answer a few of your points:

• I will definitely look into vermicomposting some more as quite a few of you mentioned it.
  But i was trying to avoid that kind of idea as a lot of people in my market (people new to composting) find food scraps 'gross', so i cant see them dealing with worms. but ill do some more research on the topic.
• In terms of shredding material the device will have a shredder to speed up the process, but i am working out whether it should be located in the device (so things are just shredded as you put them in) or on the outside (so you shred/blend materials before tipping them into the bin)
• I understand your concerns on sanitation issues regarding the chopping board, but part of our project is to include multiple functions so it is just a possible option. To combat this though the outside of the machine and chopping board are covered in an Superomniphobic / Antimicrobial
  Molecular Coating, which prevents anything from sticking to them and kills an bacteria that comes into with the surfaces, keeping the chopping board and exterior of the machine sanitary.
• There will be a spout located at the bottom of the machine to collect excess liquid at the base of the compost, as it can be used a nutritious plant feed
• To get air to the pile whilst keeping it sealed and preventing smells, there will be aerating blocks inside which provide oxygen to the pile and a series of carbon filters located around the machine. These allow air to the pile but kill bad odors.
• The machine also has carbon, nitrogen, temperature and moisture sensors which constantly measure the pile to ensure it is at optimal composting conditions.
• I understand the point you make that using electrical power is anti-green, and to be perfectly honest it is. But the angle i am using is that the power needed out ways the detrimental impacts of food waste... which it does.
  But the machine can still operate without power, obviously just with less functions and a longer period to produce compost.
• I do still need to do some more testing though around size, as different households produce different amounts of waste. An option is to have the machine available in a few different sizes, large, medium, small?
• A small indoor compostor that deals with food waste has a potentially huge market as well for flats and apartments, a market which is only getting bigger as well

I know all this seems a little far fetched but as toxcrusadr mentioned this is an educational project so we can push the boundaries a bit. Plus i am designing a product for the market in 2-3 years time, when these technologies will be drastically cheaper.

Thank you again though for taking time to respond to this post and i hope to hear more from you. Please feel free to just blast queries, questions, ideas etc.

Do you know about bokashi? Microbial culture that would be ideal for such an environment - fast decomposition, low odor. People use it in their kitchens.

I have done a lot of research into bokashi so far and it is hopefully going to instrumental in my project. I am just looking at whether the liquid or bran version is more effective at speeding up decomposition.