Home composting is the process of turning household waste into compost. Composting breaks down organic materials, such as food scraps, into nutrient-rich compost. This practice helps families improve soil health, reduce the amount of waste sent to landfills, lower methane emissions, and decrease the amount of food that is wasted.
History
Composting began during the Neolithic Age in Scotland, but home composting started much later. Indoor composting, which is also called home composting, was discovered in 1905 by Albert Howard. He worked on developing this practice for the next 30 years.
J.I. Rodale, known as the pioneer of the organic method in America, continued Howard's work and improved indoor composting starting in 1942. Since then, many different composting methods have been created. Indoor composting helped with organic gardening and farming and led to modern composting techniques. At first, it involved a layering method. Materials were stacked in alternating layers, and the pile was turned at least twice.
Fundamentals
There are two main methods for home composting: aerobic and anaerobic. Aerobic composting uses oxygen to break down organic materials and is the preferred method for home use. Aerobic composting has advantages over anaerobic composting, such as producing fewer harmful byproducts. An example of anaerobic composting is bokashi composting. While aerobic composting releases some carbon dioxide, anaerobic composting produces methane, a greenhouse gas that is much more harmful than carbon dioxide. Aerobic composting works faster because oxygen supports the growth of decomposing microorganisms. This method requires larger bins, oxygen, moisture, and turning the pile (unless worms are used).
Composting at home uses different types of organic waste. Composting needs two types of materials: "green" waste and "brown" waste. This is because organic waste requires four elements to decompose: nitrogen, carbon, oxygen, and water. To make compost, the right balance of carbon and nitrogen must be kept, along with proper oxygen and water levels. A good carbon-to-nitrogen ratio is 25 to 30 parts carbon for every 1 part nitrogen.
All compostable materials contain carbon, but they have different amounts of nitrogen. "Green" materials are wet and have less carbon compared to nitrogen. These include leafy or fresh organic items. "Brown" materials are dry and have more carbon. Too much carbon makes the compost pile too dry and slows decomposition, while too much nitrogen makes the pile wet, slimy, and smelly. To achieve the best balance for decomposition, use 2 to 4 parts brown materials for every 1 part green materials in the compost pile.
Implementation
The first step of composting at home is to get a composting bin and choose a location.
Bin Type – Composting indoors usually needs a closed bin, while composting outdoors in a garden or yard can use an open bin without a cover. Compost bins can be bought online, but other options for closed bins include old wooden dressers, garbage cans, or wine crates. Open bins can be made using wooden posts, metal stakes, and wire mesh.
Bin Size – Bin sizes vary from 5-gallon bins for small households to 18-gallon bins for larger households. A container that is 3 feet wide, 3 feet long, and 3 feet tall also works well.
Drainage – Bins should have good drainage, which may require drilling holes in the bottom.
Location – Whether indoors or outdoors, place the bin in a dry and shady spot.
If the main compost bin is far from where food scraps are collected, it is helpful to have a smaller bin nearby to store scraps. This avoids the need to move frequently to the main bin.
The next step is to gather materials for compost layers. Common household items include food scraps, coffee grounds, tea bags, and shredded paper. To keep the right balance, use about 2 to 4 parts of brown materials (like dried leaves or paper) for every 1 part of green materials (like fruit or vegetable scraps). Breaking materials into smaller pieces helps them decompose faster.
There are different composting methods, but the most common at home are aerobic composting with worms (vermicomposting) or without worms.
Home composting can be done by layering. Start with a layer of coarse materials to allow airflow, then alternate layers of nitrogen-rich (green) and carbon-rich (brown) materials. Mix the layers together. Place food scraps in the center of the pile and add soil on top after each few layers.
For vermicomposting, add about one pound of worms to the top of the soil layer. The worms need bedding made of materials like newspaper or shredded paper. Red wiggler worms (Eisenia fetida) are recommended because they can eat half their body weight in one day. Vermicomposting can happen indoors or outdoors, but it is best to keep the worm bin indoors to protect the worms from extreme temperatures. Vermicomposting takes 2–3 months, which is faster than composting without worms (3–9 months). It also needs less care, has little smell, and adds more nutrients to soil.
No matter the method, add a small amount of water if the pile is dry to keep it moist. Composting without worms requires turning the pile every few weeks to keep it aerated. The more often the pile is turned, the faster it will break down. Vermicomposting does not need turning.
Compost is finished when the material is dark, crumbly, smells like soil, and has no visible scraps. Finished compost can be used as mulch, soil amendment, fertilizer, or compost tea.
Environmental Benefits
Home composting helps improve soil health in three ways: by supporting living things in the soil, by adding important nutrients, and by making the soil stronger. Compost contains three main nutrients—nitrogen, phosphorus, and potassium—as well as other helpful elements like calcium, iron, magnesium, and zinc. These nutrients support the health of both soil and plants. Compost acts as a natural fertilizer instead of using man-made fertilizers that contain harmful chemicals. It also helps soil hold more water, work better, and produce more food. Compost adds helpful microbes that increase nutrients and create humus in the soil. Humus acts like glue, holding soil particles together and helping prevent soil erosion.
One benefit of aerobic composting is that it reduces methane emissions, a powerful greenhouse gas that harms the environment. Food waste and packaging make up 70% of household waste that ends up in landfills. About one-third of all food produced is wasted. Over 95% of food waste in landfills produces methane, carbon dioxide, and other greenhouse gases through a process called anaerobic digestion. For example, meats like beef are major sources of methane in landfills. These gases trap heat in the atmosphere and worsen climate change. Scientists predict that by 2050, greenhouse gas emissions from food production alone could increase by 80%. Home composting can reduce landfill waste and lower methane emissions.
When food waste is thrown away and enters waterways, it can cause algae blooms. Algae blooms produce harmful emissions that affect the health of animals and humans. A process called eutrophication, which happens when there are too many nutrients in water, leads to large algae blooms that damage drinking water and create "dead zones" where marine life cannot survive. Algae blooms also contribute significantly to global methane emissions.
Making synthetic fertilizers releases greenhouse gases. Using compost instead of synthetic fertilizers can reduce these emissions. By reducing food waste in landfills and using homemade compost as fertilizer, households can lower their carbon footprint.
Food waste contributes to the hunger crisis, where 690 million people worldwide do not get enough food. Households are a major cause of food waste. A study in Melbourne found that 40% of food waste happens after food is purchased by consumers. This waste increases energy use, emissions, and costs. About 40% of food produced is thrown away. In 2010, the U.S. Department of Agriculture estimated that 133 billion pounds of food and $161 billion worth of food were wasted. Home composting can reduce household waste by using food scraps productively instead of throwing them away.