Four Ways To Compost Indoors

05/27/2010 12:06 pm ET | Updated May 25, 2011

For those of us without access to backyard, frontyard, or even sideyard space in which to compost our food scraps, there are still ways in which we can participate in this wholesome and environmentally sound pastime from within our own homes.

You may wonder, if we lack yards in which to use our freshly-produced black gold, why would we want to compost in the first place? First, composting reduces the amount of solid waste we dump into landfills, and turns that waste into a nutrient-rich soil which is gold for gardens. If we took those same food scraps and put them into sealed plastic garbage bags which then get buried in a landfill, those scraps might very well outlast us-- typical landfill piles lack the necessary ingredients (moisture, air, and sunlight) required for decomposition. And sealed plastic garbage bags definitely lack those necessary ingredients. Plus, you know, we're running out of space in which to dump our garbage. So by composting, we're lightening our planetary load, and giving a little bit of goodness back to mama earth. Second, family and/or friends with yards will be so happy to get our homemade compost for their gardens! It's almost like baking them cookies! but not really.

So for my fellow yardless dwellers, I present Four Indoor Composting Options:

1. NatureMill Indoor Composter

The Queen of indoor composting, the NatureMill Indoor Composter automates the whole process and nearly eliminates possibility of user error. It "recycles its weight in waste every 10 days, diverting up to two tons of waste from landfills over its life... NatureMill uses 5 kwh / month of energy - or about $0.50/month - less than a garbage truck would burn in diesel fuel to haul the same waste. It is made from recycled and recyclable materials."

On one hand, it seems kind of bizarre to spend $300+ on a machine which composts food scraps, especially when it's possible to build an outdoor compost pile or indoor vermicomposting bin (see below) for $30 or less. On the other hand, the Naturemill is fully automatic (for someone who has trouble even keeping succulent houseplants alive, this is a major plus), built from "recycled + recyclable polyethylene (stamped with the "5" triangle recycling stainless steel and aluminium internal components"), and draws very little wattage. It can process up to 120 pounds of scraps per month or as little as a pound per day. They even have a model which can compost pet waste! Also, it produces enough heat to be able to process dairy, meat and fish scraps, which can further reduce the amount of waste that goes into the garbage can.

Full disclosure: I received a Naturemill XE unit to review, and am completely in love with it. I had been wondering for years if this machine was worth the investment, and my personal opinion is yes, yes, yes. I get a thrill adding my food scraps to the unit and watching gorgeous black compost produced within days. I don't have a garden nor need for the compost, but I get so excited giving the black gold away to those who grow things. Then again, I'm kind of a composting geek, and this is the sort of thing which rocks my world.

2. Bokashi

Bokashi bucket composting

"Bokashi (Japanese for "fermented organic matter") is a method of intensive composting"-- and it's supercool-- basically, the bokashi (a dry mixture most commonly made from bran, molassas, water and "effective microorganisms (EM)") ferments your food scraps in an almost odor-free way-- the process is reported to smell like apple cider vinegar!

Bokashiman says: "Simply place your kitchen waste in the bucket, sprinkle a small amount of the [bokashi] mixture over the waste, slightly compress and reseal the container. The beneficial microbes immediately go to work to ferment the food scraps, releasing valuable nutrients and enzymes, without the problems of odour, heat or insects. The organic material does not breakdown, it pickles."

You can purchase a full starter system for between $60-$75 (shop around for different prices), or make your own for free (plus the $10ish cost of the bokashi) by reusing two restuarant-grade nesting plastic buckets, plus lid (you can see the concept here).

"The great thing about Bokashi Composting is you can put ANYTHING in it. Now granted, you do not want to add an overt amount of liquids, and paper is a waste. But jellies, condiments, MEAT!!!, dairy, and all food scraps and vegetable waste. Bones aren't such a good thing but they do break down." The comments on that post are incredibly helpful, and give good insight into how bokashi works.

The Bokashi method is a great choice because of its small footprint, lack of odor, non-electrical nature, and seeming ease of use-- however, the downside is that you have to keep purchasing bokashi (the microorganisms) as you go along (though you can also make your own)-- and while it's not expensive (a $10-$12 bag should last a few months), it will be a lifelong cost. Also, the fermented waste must be transferred to a compost pile or buried into soil in order to finish the process-- so factor that into your tiny choosing. It also seems like you need to have two bucket-systems working at the same time: one for collecting current scraps/bokashi layers, and the second for letting a full bucket of scraps/bokashi ferment for 2-3 weeks before transferring outside. Maybe not the hugest deal, since even two of the buckets take up less space than the Naturemill, but still worth noting.

3. Vermicomposting

vermicomposting worm bin can o wormsVermicomposting is the most common form of indoor composting: red wriggler worms are contained inside a ventilated bin and used to break down organic matter into rich soil. You can either purchase a ready-made system (including Karina's choice: The Worm Condo) or DIY your own for a very low cost (plus you get to mail-order worms!). The bin can be small enough to fit underneath your sink and thus take up very little space. Once you overcome the squick factor of the wrigglers, vermicomposting is an incredibly efficient way to produce ready-to-use soil with no use of electricity or costly addititves.

It seems like vermicomposting is supereasy for some folks, and supertricky for others. In order for the worms to thrive and odor to be kept at bay, you need to maintain the proper balance of moisture and food-- too much of either and you'll end up with dried-up twigs where your worms used to be. It may be a bit of a balancing act, but it's also hands-down the most efficient way to compost indoors. Heck, if Martha and The NY Times reported on vermicomposting, you know it's a good thing!

If you run into issues with your worms, check out The NYC Compost Project's troubleshooting guide for ideas. And if you're still unsure about the potential of worm poop, check out the TerraCycle success story.

[Image via]

4. Let Someone Else Compost For You

Community Garden compostingThis one almost seems like cheating, but since it's the method I used for years I figure it's valid enough to list here. Collect your kitchen scraps and drop them off at a local community garden, farm, farmers market, co-op, or greenmarket which is set up with a collection program, and they'll do the actual composting for you. I kept my scraps in a bag in the freezer and dropped it off periodically-- this delays the decomposition process (no smell) and also kills any fruit-fly eggs which might be living on the scraps.

Here in NYC, the Lower East Side Ecology Center collects kitchen scraps at the Union Square Greenmarket and at their home base on East 7th Street. Or, find your local community garden and ask if they accept scraps. If you're outside of NYC just do a few searches and see what's going on nearby. Also, be sure to check with your collector as to their specific preferences-- some are able to accept meat and dairy scraps, and others aren't.

[Image by Killbox via Creative Commons]

What's your indoor composting method of choices?