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Stopping the Food Waste—An Introduction to Composting

Focusing on the ‘Rot’ and ‘Repurpose’ of the Five Rs

The tragedy of food waste.  ©Taz -  CC BY 2.0
The tragedy of food waste. ©Taz - CC BY 2.0

One billion tons ​of food is wasted every year—​that amounts to one third of all food produced globally, according to the United Nations Environment Programme’s Food Waste Index Report 2021.

About 8​% to ​​10% of global greenhouse gas emissions are associated with food that is not eaten. But a growing awareness means more people​—​whether at home or in their place of study or work​—​​​are looking at reducing, reusing​,​ and repurposing what they consume.   

The Five Rs  

The Five Rs are an extension of the Three Rs​—​​Reduce, Reuse, Recycle​—​​​a slogan that became popular in the 1970s to encourage people to cut down on waste. Today it is common to talk about the Five Rs, which extends the original idea to cover ​“​Refuse, Reduce, Recycle, Reuse, Rot.​”​

Bryan F​.​ Staley, president and chief executive officer at the Environmental Research and Education Foundation states: “Overall, the Five Rs provide a person with perspective on how their habits can influence how much waste they create and how they can take specific actions to make these actions more sustainable. In that respect, it is notable to point out that the Five Rs are essentially a recipe for changing individual behaviors. In many cases, to follow them may require multiple changes, which may result in a substantial change in one’s lifestyle.”   

Refuse and Reduce  

People should say “no” to single-use items, like coffee cups and plastic cutlery​,​ ​as well as ​other free material such as magazines, flyers​, or pens, and buy and consume less so that waste can be reduced. 

People should say ‘no’ to single-use items like coffee cups and plastic cutlery​,​ ​as well as ​other free material such as magazines, flyers​, or pens and buy and consume less.

Linda Norris-Waldt, deputy director and director, advocacy, corporate and chapter relations at the US Composting Council, says: “Reduce food waste—find ways to stop generating the amounts of food waste by shopping more carefully, ordering at restaurants more carefully, and better aligning the supply chain (farmers growing what is “on demand” from their customers so as not to create surplus, and the supply chain accepting imperfect produce, for example).” 

Reuse and Recycle 

Instead of sending things to landfill, reuse, repair, or recycle them. In the case of food, “Reuse = the rescue of food for both people and animals,” says Norris-Waldt. 

Rot and Compost

Hannah Blaufuss, program analyst, materials management branch at the Office of Resource Conservation and Recovery at the US Environmental Protection Agency (EPA), claims that although “rot” refers to composting, the terms are not interchangeable.

That is because rotting is a general term in which organic matter decomposes, while composting is an aerobic process that takes effort and is part of a circular economy. She explains: “In biological systems, such as the food system, circularity includes reducing the production of surplus food, ensuring that surplus food feeds humans first, and then recovering nutrients from food waste. We can do so through composting, for example, returning nutrients to the soil to promote soil health, crop productivity, and climate resilience.”  

Composting Food Waste at Home

The EPA suggests that food that can be composted at home should be divided into nitrogen-rich material known as “greens” and carbon-rich material, known as “browns​​.”​ Greens include fruit and vegetable scraps, grass clippings, coffee grounds and filter paper, paper tea bags​,​ and eggshells. They can be combined with “browns​​​,”​ such as dry leaves, twigs, shredded paper that is not glossy or colored, as well as brown bags and cardboard (without any coating, tape, or glue) and untreated wood chips.  

“Browns,” “greens” and in-betweens.  ©Meineresterampe/Pixabay
“Browns,” “greens” and in-betweens. ©Meineresterampe/Pixabay

Food that cannot easily be composted at home include meat, fish and bones, cheese and dairy products, pet litter, fats, oils and grease, glossy paper, diseased or pest-infested plants, compostable bags, or cooked food. 

Blaufuss explains: “All food can be composted, but not all food may be accepted at the compost site that is locally available. For instance, food waste sent to a large composting facility will likely take bones, dairy, and other animal products because they can ensure the compost temperature gets high enough to kill off any pathogens these materials may carry. On the other hand, if your food waste goes to a backyard or community compost pile or bin system, animal products may not be appropriate or accepted because of the temperature or time required to break down these materials.” 

“If your food waste goes to a backyard or community compost pile or bin system, animal products may not be appropriate or accepted.”

Norris-Waldt adds: “For backyard/community garden composting, bones, fats, grease and oils can be collected for industrial composting.” So, it is important to know what kind of food a local facility accepts. 

Brenda Platt, director, Composting for Community Project at the Institute for Local Self-Reliance, offers advice on what a home compost needs: “It’s an aerobic process, which means it needs oxygen. Piles that don’t have enough air can smell. You also need to have adequate moisture to make the composting microbes happy and feed them a balanced diet.” She suggests adding twice as much brown material as green material.  

Vermicomposting with soil amended by bokashi fermentation.   ©Malcolm Fowles (CC BY-SA 4.0)
Vermicomposting with soil amended by bokashi fermentation. ©Malcolm Fowles (CC BY-SA 4.0)

In urban areas, pickup services can collect homeowners’ food scraps for composting, or there might be drop-off sites. Residents can also produce their own compost in their own back yards using several methods. A vermicompost involves using worms to break down the material, while a traditional composting method involves breaking down the material in a pile or bin. Less common methods include bokashi (which consists of fermenting food waste) and using soldier flies. 

Kitchen compost bin.  ©Sarah Stierch (CC BY 4.0)
Kitchen compost bin. ©Sarah Stierch (CC BY 4.0)

In rural areas, composting can also range from backyard piles to industrial facilities. On farms, composting might only consist of material generated on site, like manure and crop residues. Or farmers might collect food waste from surrounding communities.

Composting in an Industrial Setting

Industrial facilities can break down a larger range of material than home composting piles, for example, through windrows and aerated static piles. Blaufuss explains: “Windrows are long piles that are turned regularly by hand or machine to maintain appropriate temperature and levels of moisture and oxygen. Aerated static piles use systems of pipes to allow air to penetrate the interior of the piles. In-vessel composting is another large-scale method and is like a bin. This type of enclosed system allows for good control of the environmental conditions, such as temperature, moisture, and oxygen. The compost is mechanically turned or mixed to make sure it stays aerated.” 

Rural composting site in Germany. ©Crystalclear/Wikimedia CC BY-SA 3.0
Rural composting site in Germany. ©Crystalclear/Wikimedia CC BY-SA 3.0

Community Composting

In Fayetteville, Arkansas, food makes up 18% of all waste sent to its landfill. The city authority hopes to divert 40% of all waste away from its landfill by 2027. With a population of 97,000, covering 22,000 households, it owns and operates its own composting facility. In 2018, it started a commercial collection program for schools and restaurants. In the fall of 2022, it began a residential program, in which residents drop off their food waste at one of seven sites for free. All fruit and vegetables, cooked meats, compostable food service items,​ and bags are accepted. The compost that is created can be bought from the city or is given away to community gardens free of charge. 

At Boston College, Massachusetts, a student compost program increased the amount of food it saved from being wasted by ​students by ​about 27% from 2016 to 2017​—​​from about 300 to 380 tons. It has now expanded its compost program to other locations at the college, including two of its dining halls and a student-run café.

Boulder County Jail in Colorado achieved close to a 60% increase in the amount of material composted between 2015 and 2017, through its kitchen composting program. The kitchen, run mainly by inmates, serves up three meals a day ​to 800 prisoners. The jail increased its compostable food collection from 10.64 tons in 2015 to 15.68 tons in 2016 and 17.79 tons in 2017. 

Listen to a podcast about community composting in Atlanta​ by the Institute for Local Self-Reliance with Khari Diop, the founder and CEO of ThinkGreen Inc​. 

Benefits to the Environment

Composting has numerous environmental benefits. They include less methane in the atmosphere, reducing or eliminating the need for chemical fertilizers​,​ and improving agricultural crop yields. The process can also renew habitat by improving soil, enhancing water retention​, and helping capture and store carbon dioxide. And compost can, of course, be used to grow food or support other agricultural activities. 

Composting can help renew habitat, enhance water retention, capture and store carbon dioxide, and grow food or support other agricultural activities. 

Negative Effects of Composting

If properly managed there are few negative effects, claims Blaufuss. ​But material that is contaminated with plastics, heavy metals, and chemicals can produce adverse effects. That’s why it’s important to separate food waste from packaging and other non-compostable material carefully.  

Recent Developments

Norris-Waldt says there is an “awareness around the world that food is not waste, it is scrap that can be handled at any level of the food waste hierarchy.” 

And there have been policy developments too. Staley adds: “Increasingly, policies are shifting more towards organics diversion with composting being a key activity to achieve this. Communities as well have begun increasing education around composting and working to develop solid business cases for integrating composting as an option, which enhances convenience and ultimately the level of people that will participate. While the pace is slow, things are advancing.”  

Meanwhile, composting technologies are also getting better—for example, a variety of supplements can be added to enhance the process, and mathematical modeling and optimization have helped to cut costs and offer optimum solutions. 

A Last Resort

The EPA is keen to promote practices that reduce the amount of food being wasted in the first place. Composting is a good solution for food waste that would otherwise be sent to landfill, but the focus must be on following sustainable food management practices.


*Yasmin Prabhudas is a freelance journalist working mainly for nonprofit organizations, labor unions, the education sector, and government agencies.


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