Every year in the United States, we throw away nearly 40 percent of our food.
In 2015, the Environmental Protection Agency estimated that U.S. landfills contained more food than any other material, with fully 22 percent of landfill volume being food waste. Left to decompose, the food in landfills begins to emit high levels of methane, which is nearly 30 times more powerful than carbon dioxide as a greenhouse gas. It’s hard to imagine, but 20 percent of total U.S. methane emissions can be traced back to landfills!
Now is the time to begin composting. Instead of throwing out food scraps, we can use them for good — benefiting our soil and reducing methane from landfills. According to the EPA, compost helps enrich the soil, so it can retain moisture and suppress the number of plant diseases and pests. It also reduces the need for chemical fertilizers, by encouraging the creation of beneficial bacteria and nutrient-rich materials. By composting, you are able to help stabilize the soil’s pH, help hold nutrients in the soil, and improve the overall soil structure (Planet Natural Research Center). And since composting is an aerobic decomposition process, no methane is produced in the process (Agriculture and Food Department of Western Australia)!
To teach you about how to compost and how easy it is to get started, we spoke with Ron Bakus, Ph.D., one of our principal scientists, who vermicomposts at home! Read on for his tips and tricks on what you need to start composting.
What is the difference between vermicomposting versus composting?
Composting is the process of breaking down organic matter (think carbon, hydrogen, nitrogen, and oxygen-containing molecules) into a soil conditioner containing humic acids by the action of microbes. Where vermicomposting and regular composting diverge is that in vermicomposting the breakdown of organic matter is mainly driven by the presence of earthworms (with a side of microbes), whereas in compost, the main driver is microbes and heat. In my experience, an important selection criteria for whether you want to be a home compost-er or vermicompost-er is the space with which you have to work. Small spaces are great for vermicomposting and larger spaces are good for composting. Why, you ask?
Composting: just time, air, heat, and space
To have effective composting, you need heat, which means that small piles or cold climates can work against you. You need to make sure that you have enough food and yard waste to create a pile of at least 1 cubic yard (essentially a 3’x3’x3’ cube or 27 cubic feet). You may see tumble composters advertised online. In general, unless they are large (greater than a 55-gallon drum or 9 cubic feet) or are well insulated, I’d suggest staying away.
Once you build a large pile (see below about greens and browns), the microbes found in food and yard waste will begin to work their magic and begin generating heat. The pile needs to get hot because the heat creates a happy home for the microbes that break down the organic matter, and helps destroy fungal pathogens and potential weed seeds found in the organic matter.
What are the differences between greens and browns?
In the composting vernacular, greens are rich in nitrogen (N) and browns are rich in carbon (C).
In order to have a healthy pile, you’ll need a mix of the two in order to achieve the desired C:N ratio of 25:1.
Greens, such as grass clippings, coffee grounds, vegetable scraps...almost anything that was recently living, have a C:N ratio of below 20:1. Browns, including fall leaves, pine needles, straw and hay, sawdust, paper, and dryer lint are over 30:1.
What I use in my vermicomposting at home is a pile that is two parts browns to one part greens by volume. If your ratio is off, you may face a pile that develops an ammonia odor (C:N ratio too low, add browns), or that only slowly composts (C:N ratio too high, add greens).
What do you need to start composting at home?
Besides a large pile of greens and browns, you’ll also need to invest in a thermometer so that you can monitor the heat of your pile and shovel or pitchfork to turn the pile. Like I mentioned before, your pile will need to be hot so that the bacteria are warm enough to break down the organic matter and destroy pathogens to create healthy compost. The pile will start off low and then gradually rise above the ambient temperature in the pile.
Reaching temperatures between 110 and 160 degrees Fahrenheit in the pile is ideal; any temperature hotter than 130 degrees Fahrenheit will kill pathogenic microbes, and over 160 degrees Fahrenheit you risk killing the beneficial microbes that are doing the composting. Eventually, the pile will cool down, signaling an end of the composting process.
How do I maintain my pile?
Once you have created the pile, you have to maintain it. The microbes inside need moisture and air. The pile should be moist enough that if you squeeze a handful, some drops will escape, but not so wet that it's dripping. Your pile will need to be turned regularly because the inside will be hotter than the outside, and each part of the pile will need to be aerated to maintain an aerobic environment in the pile so that the microbes can do their work. Every week or so, you’ll need to take a pitchfork or shovel and stir the pile to introduce air and mix inside and outside portions.
What about vermicomposting?
Vermicomposting is basically a small-scale composting method, where instead of having to churn your pile, the worms will do it for you and instead of needing a large area, you can compost small amounts (think handfuls at a time). The same C:N ratio and moisture rules apply to vermicomposting, but whereas you want the compost to get hot, you want to keep your worms between 50-80 degrees Fahrenheit (so insulate them in the winter from frost and keep their container out of direct sun). You can’t destroy pathogens that may be present by vermicomposting (so don’t try and vermicompost any moldy vegetables), but it is a quicker way to compost a smaller amount of food waste and yard waste. In addition, you can buy worm bins to contain the worms and make it easy to separate out the small amounts of vermicompost that you generate.
Anything else you’d like to tell someone who wants to start composting at home?
Read more online and educate yourself; what I’ve given here is a brief summary. Large chunks will take much longer to break down than small pieces, so consider shredding or blending materials before adding to your pile. Beware things that contain preservatives, as this can slow down the composting or vermicomposting process. Never try and compost things that are high in protein (meat, fish, dairy, tofu, etc.) or fats/oils (dairy again, cooking oils, grease), and only sparingly feed things that are rich in carbohydrates (bread, grains, etc.). If you’re having trouble getting your compost pile started, you can buy different activators or bacterial inoculants that will help get your pile going, but first, check your pile for obvious problems.
If you don’t have any space to compost, there are other ways to help reduce waste. Many cities and towns have their own composting programs, generally run by the waste management division of your local government. In Santa Barbara County, where we are based, the city provides residents and companies with compost bins that are picked up weekly with the normal trash service. This service allows you to help reduce carbon emissions with minimal effort.
Want more tips and tricks on how to end food waste in your home? Follow us on Instagram or Twitter or search for Apeel produce near you!
Special thanks to Ron Bakus, Ph.D., Director of Extraction Sciences, Jess Perkins, Ph.D., Director of Sustainability, and Charlotte Sedlock, Technical Analyst (Environmental).