How to Compost Kitchen Waste
Food waste sealed in a plastic bag on a landfill site doesn't decompose properly. Instead, it produces methane, a greenhouse gas, which contributes to global warming, as well as a liquid, leachate, which can contaminate water supplies.
Composting your kitchen food waste is easy and requires little time, effort or space, depending on which system you use. The compost is invaluable for the soil in your garden or potted plants: It's a complete and natural food for the soil, helping to improve its structure, water-retaining abilities and overall health.
Worm composting is small enough to keep on a balcony, patio or in a porch, so it's ideal if you don't have much outside space. It's also one of the cleanest, neatest and easiest composting systems to use. A ready-made kit provides both the bin with its lid and the worms. As you fill each layer with small amounts of scraps and leftovers, the worms work their way up through the layers, eating the waste (they consume up to half of their body weight a day). It's this action that speeds up the composting process, leaving you with rich, dark compost in the lowest tray after only a few months. After you've emptied out the compost, the empty tray can be placed on top of the stack and filled with more food waste. The liquid that collects at the bottom of the bin should be siphoned off regularly, but it makes a wonderful tonic for your plants when diluted 1:10 with water. Store it in screw-top wine bottles until you need to use it.
If you regularly add a few handfuls of chopped food waste and shredded dry fiber (cardboard is best), ensure good air circulation, a fairly constant temperature and prevent water logging, this efficient composting system should last for years.
The Best Waste for Worm Composting
- Raw or cooked fruit and vegetable peelings
- Pasta, rice and bread
- Dried and crushed egg shells
- Teabags and coffee grounds
- Dry fiber, such as torn-up egg crates and empty toilet rolls, to make up 25 percent of the contents
Avoid citrus fruit and onion peelings (which cause acidic conditions), plant seeds, meat, fish, dairy products, dog and cat droppings, spent tissues, grass cuttings and leaves, diseased plant material and anything in excess.
You can recycle both kitchen and garden waste if you keep a compost heap or bin in your garden. An insulating box or bin is essential: make your own from pieces of wood or buy a readymade wooden or recycled plastic version. A lid or covering, such as a piece of old carpet, keeps the contents of the bin warm and the rain out. Position the bin on an area of soil so that composting creatures such as worms and soil micro-organisms can help to break down the organic waste in the bin. If you want to pre-compost your food waste and accelerate the composting process, add Bokashi active bran to the food waste and leave it to pickle for two weeks in a bucket before adding it to the compost bin.
Kitchen waste is high in moisture and has very little structure once it has decomposed. Add a supply of dry material, such as cardboard, scrunched-up paper, coarse twigs and stems to stop the compost heap collapsing in on itself and becoming slimy. Wine corks, party hats and streamers can also be added to the compost heap, as can tissue paper, which biodegrades quickly. Cardboard packaging from food and gifts can also be composted.
Check the base of the heap after several months and dig out any dark, well-rotted compost. Mix up the remaining matter with a fork, and water it if it seems dry; if the heap is too wet, add some dry, bulky material. Acidic conditions inhibit decomposition, so occasionally add a little ground limestone or gardener's lime.
Organic Material to Compost
- Vegetable and fruit peelings
- Tea leaves and coffee grounds
- Crushed egg shells
- Grass cuttings and weeds
- Paper, paper towels and newspaper
- Leaves from non-coniferous trees and shrubs
- Woody prunings
- Straw, hay, wool, sawdust and pets' bedding
- Vacuum dust
- Wood ash
Avoid meat, fish, and cooked food, weed seeds, diseased plant material, disposable diapers, glossy newsprint and coal ash.
Food Waste Facts
It is estimated that five million tons of waste is generated over the festive period in the United States, but only a fraction of that amount will be recycled. Families can reduce their festive waste with careful planning and recycling practices.
The average American family throws away 14 percent of the food it purchases each year. This translates to approximately $600 per year spent on wasted food.
Composting food helps reduce the amount of material in landfills.