Food is completely compostable, yet we throw it out all the time. That's a damned shame because once it goes into landfill, it mixes with the other crap in there and turns into a toxic stew of cheese-topped keyboards and plastic bags filled with rotting meat.
This is a huge problem. Food, along with paper, makes up about half of all landfill--New Yorkers alone throw out about two pounds of food per person per day, once you factor in all the restaurants--and food is the #1 least recycled material according to the EPA.
To do my part for the environment, last year I began looking into composting, which can be tough whether you live in the city or country; it requires a vermin-resistant facility of a certain temperature consistency, not to mention the discipline to regularly agitate the mix and/or maintain a worm population, if you go that route. In short, composting is not an easy option for the time-pressed.
So I was very excited to review NatureMill's Automatic Compost Bin, which promises to turn food into dirt with very little hassle--indoors and in a space-considerate way, which is important to us urban dwellers with tight apartments. In the first few weeks I was surprised at how easy the process was; I then decided to do a long-term review, covering six months of usage, to see if it continued to be easy or if unanticipated problems would crop up. Form Factor
The machine is roughly the size of an Apple G5 or similar desktop PC tower. It's meant to go in an under-counter cabinet in your kitchen, though the aesthetics are unobstrusive enough that it could go on a countertop or on the floor next to the 'fridge without drawing an interior designer's ire, aside from its mass.
The entire top is a swing-up lid, hinged in the back like a waste pail. A removable panel on the bottom front lets you pull out the bin that will hold the composted end product. On the top front is a simple panel containing a single button that you press when your compost is ready to go. (More on this later, in "Operation.")
I was a little puzzled by the choice of the housing material, which appeared to be styrofoam; but in fact it's recycled (and recyclable) polypropylene, which is both eco-friendly and durable. This machine was built to last and to be recycled at the end of its life.
The side of the machine I tested was covered with large decal-like panels that come in different colors. Because these panels are smooth, it makes it easy to wipe off any food or liquid that gets on them as a result of you dumping food into the top and spilling a little. It's easy to keep the machine clean.
You plug the machine into the wall, and it draws an extremely low current--about 5 kwh per month, which adds about 50 cents to your bill. Needless to say, energy-wise this takes "less than a garbage truck would burn in diesel fuel to haul away the same waste," as the literature points out.
The very first time you use the machine, you need to dump a little dirt inside of it, about a cup's worth, in order to "establish the cultures." (After that you needn't do it again.) This has to be ordinary soil, whether frozen, sandy, or clay, and can't have any rocks in it. It also can't be packaged soil. I stopped by a local park and filled a paper coffee cup with dirt. This worked fine.
You then add a dash of baking soda, which helps balance the acidity of whatever food you throw in there.
The final starter material you need to dump in is a cup's worth of sawdust or sawdust pellets, which some lumberyards stock. If not you can order them from NatureMill on the cheap, and this isn't one of those business scams, like disposable razor blades, where they try to squeeze you into regularly buying expensive ancillary materials: A six-month supply of sawdust pellets only runs you eight bucks, which is less than I spend on lunch each day.
I eagerly dumped several days' worth of leftovers into the machine--a mixture of bread, rice, beef, chicken, sauce, and various vegetables. The machine makes a grinding noise every four hours as it turns the ingredients over, mixing everything up; a low-wattage heating element inside speeds the break-down process. The results? After just a few days, I opened the lid and found a machine full of dirt!
Let me clarify that--"full" is a relative term, as during the composting process a rather amazing thing happens: Roughly 70% of what you've thrown in simply disappears. The water in the food evaporates, and what's left breaks down.
Practical daily usage
Over the course of the next six months, I used the machine daily, and was surprised by how many times a day I had cause to throw something in there. It never occurred to me how often we throw organic things into the trash. Coffee grinds, cooking detritus like eggshells and vegetable waste, banana peels, fruit rinds, leftovers, stale bread. Some of the takeout places I order from throw free bags of potato chips in there, which I don't eat; rather than throw those out, I opened the bags and dumped the contents into the NatureMill.
To balance out the mixture, you add a dash of baking soda and roughly one cup of sawdust pellets for every five cups of food. This isn't terribly complicated, and after a while you subconsciously learn to estimate how much sawdust to throw in there, the same way you estimate how long to microwave something by its mass or weight.
You can even throw liquid-y things, like yogurt past its prime and tomato sauce that's gone bad, into the machine. I balanced out the wetness with sawdust pellets and leftover starchy stuff like rice and bread to soak up the liquids. Any excess water gets caught in a little cup in the compost bin at the bottom of the machine, and it's easy to remove this cup and dump it out. If you dump too much liquid into the machine though, you can get mold; this happened to me once, and I just scraped the mold patch off the inside of the machine and dumped it into the middle of the mix. It never reappeared.
I was worried about bad smells coming out of the machine, and amazed to find absolutely none, even when there was meat and cheese in there. Opening the lid, the only thing you smell is a pleasant, earthy odor. The carbon filter inside the machine does a kick-ass job. I was also worried food scraps would attract vermin, and it did not, probably because there is zero food smell.
There are certain things you can't throw into the machine, as listed in the instructions. It's basically common sense--super-hard things like bones, clamshells and walnut shells won't quickly break down and could damage the machine. Also, long stringy things like banana peels I would cut in half cross-wise, to make sure they're no longer than roughly five inches. Any longer than that, and they might tangle up the agitator as it rotates around.
Removing the compost
I emptied the machine about once every three weeks, a figure that will vary depending on the size of your household. It's easy to tell when your dirt is good and ready by just opening the lid and looking inside: It either looks like dirt or it doesn't.
Once it's ready, you press the singular "OK" button on the front of the machine, then go do something else. The machine spends maybe 45 minutes transferring the contents into the bin at the bottom. Once that's done, you open the bottom compartment and remove the bin.
This is the point where I found there is some further work to be done. Things break down at different rates, and because I fill the machine daily, there is always a mix of compost and not-ready-for-primetime chunks of stuff in there, like fruit rinds or chicken pieces that have shrunk and turned brown but have not yet become dirt. These I would sift out with a small plastic colander or slotted spoon and throw back into the top of the machine.
What's left over is the dirt, which I dump into empty orange juice cartons. I then donate these to my friend who has a garden, or if she's at full capacity, I simply take them outside and sprinkle them into a local sidewalk flowerbed or planted tree base. Your food waste has thus gone back into the Earth, harmlessly.
Living with the NatureMill
For the first few months, the machine may or may not be noisy for you during the few periods where the agitator kicks in. This largely depends on your living situation--for example, if you live in a suburban house where your bedroom is far from the kitchen, you won't hear the thing at night.
Me, I have a special situation as I live in a New York apartment with substandard kitchen cabinets. The 19.5"-tall NatureMill wouldn't fit into my cabinets, so I had to leave it on a countertop. My bed is just a few feet from the collection of cabinets I call my kitchen, so I would hear the unmuffled machine when it kicked in at night. I'm a heavy sleeper so it wasn't a problem for me, but a friend who was housesitting for me commented that it sounded like something noisy happening far away, like a power drill being used down the hall.
After a few months the machine gets broken in, and the motor becomes less noisy. After six months of use I now rarely notice when the machine kicks in, to the point where I'll sometimes check it to make sure it's still on.
You may want to measure your kitchen cabinets to see if the machine will fit. You'll need an inch or so more than the 19.5"-height of the machine, because you'll have to install a sliding shelf so you can pull the machine out, to be able to open the lid.
Alternatively you could leave the machine on the floor, say, next to the refrigerator, which I wish I could do for the sake of convenience--a foot pedal on the NatureMill Pro model makes it easy to pop the lid open and dump food in. But I was unable to have the machine on the floor because I own two dogs. (The dogs are so good at opening things I wouldn't be surprised to find them reading my mail.)
NatureMill's machine remained easy to use throughout the length of the testing process. Because there's so little required in the way of maintenance and activity, I basically look at it as passive recycling; rather than dumping food waste into the garbage, I just scrape my plate off into the NatureMill. The machine does the rest, except for the five minutes of sifting I do every three weeks, which I consider a worthwhile time trade-off. (For details on how the NatureMill process works, click here.)
So many of the products we own are for entertainment or business, so it's nice to use an object whose sole purpose is to better the environment. It is simply amazing to be turning waste into beautiful soil on a regular basis, and an added benefit is that your kitchen garbage will no longer smell, because there's nothing in there that can rot.
I wish they made high-capacity machines like this and that it was law for every restaurant to install them. If you walk through, say, New York's Chinatown with its high concentration of restaurants, at night you can see and smell bags of discarded, rotting food everywhere. Night after night, every night. Imagine if all of that could be returned to the earth as soil, and make the city smell better to boot!
There are plenty of products that I love and use every day, but I can't recommend an iPad or a Dyson vacuum to everyone because not all of you have the need for them. But NatureMill's product is different, because all of us eat and all of us generate food waste. They've come up with a convenient, low-hassle way for us to avoid adding that stuff to landfill, and if every one of us used one it would make a huge difference in the planet's well-being.