Intrigued by this newfangled composter, I decided to test it myself to see if  it really works as claimed.  I'm not thrilled with online "reviews" which are superficial at best and in most cases are of an older outdated model or a different product all together.  I have a feeling that many of them never actually use the product but just wanted something to tweet about or post to their facebook page.  I was committed to write a detailed review of how it works, by using it myself over a sufficient period of time. 

First some background.... 

For the record, I am reviewing the NatureMill ULTRA Compost bin, in Metallic Silver, purchased directly from the company's website in January 2012.  I have no prior composting experience, other than as a child with red worm composting, which ended badly (especially for the worms).  I do a little gardening but by no means do I have a green thumb.  I am a freelance writer after all, with very little aptitude in the mechanical department. 

So I was hopeful but highly skeptical when I first heard about the NatureMill.  The composting of my childhood was difficult, slow, and GROSS!  They teach classes on composting so it must be difficult, right?  When I saw this self-contained product it just seemed too good to be true.  With skepto-radar on high alert, I took the plunge.  The bottom line is that it makes very good compost, and is very easy to setup and use.  It also has some nice features that the manufacturer doesn't even mention.  There are a few quirks here and there that people should know about, especially in the initial getting going phase, but generally it has been a pleasant experience.   

Initial purchase and shipment

I decided to buy the product directly from the manufacturer's website.  That seemed to get the best price, free shipping, free returns, no tax for non-California residents like myself, and if there were any problems their customer service would be a little more knowledgeable.  Sure enough, I did have a few questions later on, and their customer service was very responsive and detail-oriented. 

The product arrived within about a week and was already assembled and ready for use right out of the box.  It's made of some sort of squishy but strong space-age recycled material which apparently locks in the heat (important for compost I am told).  I like how they use recycled materials for the packaging - that just makes sense.  It even comes with an initial supply of sawdust pellets and baking soda to last several months - more on that later.  So there is nothing else to buy, set up, install, or assemble.  Just start composting. I plugged it in and it made a little humming sound which became nearly silent once it warmed up. 

The First Week

I had heard that you inculcate compost with micro organisms to jump-start the natural process of decomposition.  Surprisingly, there were none included in the box.  A careful review of the instructions revealed that you just start adding food slowly in the first week.  This is where I called customer service the first time, and they assured me that no special additives are needed beyond just regular food scraps.  It's kind of gross to think about it, but there are plenty of micro organisms all around us, especially on organic produce.  I will never look at a banana peel the same way again! Sure enough, midway through day three, suddenly things start to heat up as the little microbes flourish on their own. 

The manufacturer includes a very detailed list of foods to compost.  Review this list carefully.  Broccoli and related food groups (cauliflower, mustard greens, brussels sprouts) will cause problems if you keep your NatureMill indoors because they contain a nasty sulphur compound which apparently stinks when it breaks down.  I wouldn't know this personally because I avoided those and have had very pleasant smelling compost as a result.  Also you should avoid really hard things like corn cobs because they will not break down quickly or completely.  Surprisingly, you can add meat and dairy items because the temperatures generated by the compost are locked in and that kills any harmful bacteria and also takes care of the odors. 

The Mixing Chamber

Once you start adding food to the machine, it is obvious how the two chambers work in tandem.  You add food directly to the top chamber where it mixes several times each day.  This is where the magic happens.  As it mixes around each time, little grinding fins mash up the food and within days it all begins to look like dirt.  I didn't see anything in there sharp enough to be dangerous, but with repetitive motion almost everything breaks down into tiny morsels within a matter of days. 

It's hot and breezy up there, with the computer-controlled air pump and odor reducing air filter nurturing the little compost micro organisms which eat away at the food, turning it into soil.  Most of the heat comes from the compost itself so there is very little energy consumption.  I have not noticed any increase in my monthly utility bill.  You have to balance the compost, and they provide you with sawdust pellets (to up the carbon content) and baking soda (to balance natural food acidity).  I'm not sure what all that means, or any of it to be honest, so I just blindly  followed the instructions and not surprisingly everything worked out.  Apparently they did research on this so at least someone knows what's going on.  I can bake a cake too, without really understanding the underlying science of it. 

The Curing Tray

When your compost looks ready, you press the little TRANSFER button on the front of the machine.  The quick guide included with the product has nice color photos to show you what "ready" looks like.  Very convenient.  After a few months you get the hang of it without referring to the photos.  All the great looking compost falls down to the bottom chamber where it sits for another week or two in a tray for the "curing" process.  I guess the little micro organisms continue their work there in over-drive, undisturbed by the violent mixing and grinding motions. 

While the curing happens, you can add more food scraps to the mixing chamber up above so you never really have to take a break from adding items. After all, we never take a break from eating so it's nice to have a place for your food scraps every day.

Out in the Garden

The proudest moment is when you remove the cure tray for the first time, with a nice rich batch of steamy black compost.  Take it straight out to the garden because it is so powerful that it will soon start to attract earthworms and  beneficial garden insects.  I didn't want to risk that in my kitchen, so out it went to a nice corner of my garden.  Right on schedule, the lively garden critters arrived by the next week when I checked my compost - lady bugs, earthworms, and a very earthy aroma.  Apparently I haven't killed everything in my backyard. 

The compost itself was very rich indeed.  The manufacturer advises that the first batch will be wet and not suitable for gardening and to discard it, because the cultures are still waking up and not yet at their best.  But my first batch was actually ok to use.  I guess my little friends got fired up hot even in their first batch.  Sure enough, subsequent batches were a little better although it is hard to describe exactly what that means.  Try it and you will understand. 

What I found was that the compost was very mulchy in composition.  It was somewhat surprising how even egg shells and apple cores broke down into essentially dirt.  When reviewing the final compost, it does not resemble food at all except for a few odd morsels like corn cobs that never broke down in the first place.  I have only been using the compost in the garden for a few months, so it's too soon to know the difference for sure, but the flowers definitely see perkier this year. 

Final Thoughts

Overall the product performed as hoped.  Believe the hype!  It actually works.  There are a lot of nice little features that they don't heavily advertise that are worth mentioning here.  For example you don't have to keep buying the sawdust pellets, because they tell you how to get sawdust free or at a local store  (much cheaper).  Also you can review the high, medium, and low settings which geared toward people like me who don't have too much food to compost, and also for people with big families with lots of food to compost.  They will be offering a cabinet version soon, and a stainless steel version - both are too fancy for me but nice to know they're out there if you want them.

- Sidney B., Portland, Oregon