A slight constant smell of rotting food. A slimy sink bottom. Crisp scraps collapsing into liquids. Those are the usual images that come to mind when you think of composting, but today’s cleantech offers new and much more pleasant options. Recently, indoor composting has become quite simple — it takes little more than a flick of a switch, as they say, of an uncomplicated small machine right in your kitchen.
Food waste reduction has risen on the political agenda alongside ambitious material recycling, water protections, and greenhouse gas (GHG) emissions targets. In the US, food waste constitutes 15% of the solid waste stream by weight, contributes 3.4 × 107 t of carbon dioxide (CO2) equivalent emissions, and costs $1.9 billion in disposal fees. While the prevention of food waste clearly stands out as the most effective strategy for mitigating climate change through food processes, composting remains necessary to tackle the enormous amount of food that is not consumed or absorbed along its supply chain.
Composting provides an environmentally sound method of recycling food and yard waste — which together make up more than 30% of what we discard — and can reduce the bulk in landfills, where they take up space and release methane, a potent greenhouse gas (GHG).
What is Indoor Composting?
Compost is organic material that can be added to soil to help plants grow. When you think about personal composting, an outdoor bin likely comes to mind, but how do people compost indoors?
Gardener Amy Grant describes how a bioreactor works to provide adequate moisture, heat retention, and air flow for decomposition of your organic leftovers when composting indoors. “First, you must choose a composting vessel or bioreactor suitable for making compost indoors,” Grant outlines. “These containers are much smaller than the outdoor bins, so they need to be appropriately designed to provide the perfect conditions for aerobic heat production, which is responsible for breaking down the food waste.”
Bob Villa, the home and yard restoration guru, also helps to explain traditional indoor composting. The two main methods for composting indoors, which often take place in a cellar or garage, are aerobic composting and vermicomposting.
- Aerobic composting uses microbes from garden soil to convert kitchen waste and other organic material into compost, the decayed organic matter that can be used as homemade plant fertilizer.
- Vermicomposting uses worms and soil microbes to convert organic waste into worm castings (manure) and decayed organic matter.
A whole bunch of new indoor composting devices exist, however, that move composting right into your apartment or home kitchen. These small machines take your compostable waste and cook it down into a nutrient-rich, soil-like mix that you can dig into your flower, herb, or vegetable bed. Wired recently tested a variety of such composters.
My own path to indoor composting was more organic (pun intended). As a writer for CleanTechnica, the announcement for the $499 Pela Lomi appeared in my In Box, likely directed to my attention because of my articles about plant-based eating, climatarian diets, sustainable food systems, agrivoltaic agriculture, and the like. I’m really interested in the cycle of food production, harvest, distribution, processing, and consumer use.
I was excited to learn that I could move my composting habit indoors, so I sent off my deposit for a Lomi. I believe I was one of the first persons to receive a Lomi as it was released to the public.
The Lomi Indoor Composting Method
The company explains that Lomi speeds up the breakdown of organic waste into smaller fragments – similar to how earthworms break down and mix plant tissue into soil. Fragmented waste provides more surface area for microbes to accelerate the composting process. They say the end result is a natural source of soil nutrients that increase the organic content of soil, helping boost plant growth and soil enrichment.
My Lomi is slightly bigger than my toaster oven, and it needs a dedicated counter space that’s at least 6″ from walls with good circulation. Its bucket holds about one cubic foot of food waste, which seems to work out to about every other day for my family of two, and I’m a lifelong vegetarian who uses fruits or vegetables with every meal.
I turn and release the top of the Lomi, pour in the food scraps, and cinch the lid. I press one of 3 modes to activate the processing.
- Eco Express: handles food waste over the course of an afternoon, with a 3-5 hour cycle.
- Approved: good for food waste, bioplastics, and compostable commercial goods. Takes 5-8 hours.
- Grow: specifically designed for use with food waste and preserves microorganisms and bacteria most helpful to the soil. Requires 16-20 hours to complete, with a whole bunch of whirrs and an occasionally buzzing. You can also add some water and a LomiPod, a bacteria-rich pod that helps break the food down. (Carbon and LomiPods are going to be available soon at a subscription, which I intend to add.)
Regardless of mode, the device uses low energy to heat the bucket and mix it with a metal blade — a lot like my food processor. The motion stirs and swirls and divides the waste into smaller bits while warm air flows over the waste and two carbon filters, the latter of which remove odors.
I find that the quickest mode (“Eco Express”) produces a slightly larger soil product, but the difference isn’t significant enough to me to run the Grow cycle more than once a week. When I do engage the Grow cycle, I am able to introduce the soil end product right into my herb pot. The Preferred or Eco modes are fine for the outskirts of the herb bed, which I turn periodically.
Beyond Indoor Composting — Tackling Large Scale Food Waste
Composting of green waste as an alternative to green waste disposal in landfills requires an understanding of the impacts on GHG emissions and the development of effective and efficient management strategies to reduce these emissions. Management practices that optimize porosity and air flow in compost piles are promising in reducing emissions from both green waste and green/food waste mixtures.
In China, for example, anaerobic digestion technology for food waste resource treatment has attracted much attention due to its advantages. It has the ability to obtain clean energy, produce low carbon emissions, and provide suitable, large-scale treatment compared with other recycling technologies such as feed and breeding insects.
A study in Engineering journal indicates that there are attractive methods for mitigation on the large scale due to the levels of carbon, nutrients, and moisture in food waste. Bioprocessing these elements into higher value products can produce opportunities for extraction of nutraceuticals and bioactive compounds, or conversion to a variety of volatile acids—including lactic, acetic, and propionic acids—that can be recovered and sold at a profit. The conversion of waste into volatile acids can be paired with bioenergy production, including hydrogen or biogas.
If the Lomi and other indoor composting products are so efficient, isn’t it time to scale such food waste processes so that entire communities can utilize them? I imagine, in addition to area recycling bins, a section dedicated to composting. Neighbors would open a lid, pour in their non-animal waste, and a solar panel would charge a mechanism that would slowly and constantly move and churn the food waste. The resulting soil would be turned into community gardens, where the food cycle could begin again.
It sounds nearly radical, doesn’t it? Yet it’s returning to our roots (another pun, sorry) as beings that are interconnected to the environment in healthy and fruitful ways. Give it a try.