Richard Cornish and Jill Dupleix

It was apocalyptic. Flames were leaping as gas escaped through cracks in the earth at an inner-city park that had once been a tip. Recent rain had formed puddles on the earth covering the former tip and bubbles were forming. Curious, I took a lighter to the bubbles and suddenly the ground was alight. Methane. Decades of buried household rubbish, mostly food waste, was decomposing into flammable gas.

"When food is buried in landfill it produces methane which is 25 times more potent as a greenhouse gas than carbon dioxide," says Cassie Duncan of Sustainable Table, a nonprofit group that uses discussions around food to raise important issues about sustainability. "Food waste in the home is a massive problem."

Carrot-top pesto.
Carrot-top pesto. Photo: Jill Dupleix

Duncan cites some alarming statistics. "Annually Australians throw away over $8 billion dollars worth of food, most of which ends up in landfill," she says. In Sydney alone $1 billion of edible food is thrown away annually, according to the University of Western Sydney, or $1036 worth of wasted food for every household. Victorians are even more wasteful, with each household wasting around $2000 worth of food, according to Sustainability Victoria research. Every year in NSW $848 million of fresh food is thrown out, $694 million of leftovers, $371 million of packaged food, $231 million of drinks, the same in frozen food and $180 million in take away food.

That is simply the dollar value of the food to the end consumer. The net cost to the environment includes fertiliser, fuel for production and transport plus energy for processing and refrigeration. The hidden cost to the Australian economy is lost potential exports.

According to a report by the UN Food and Agricultural report, "in rich countries ... people simply can afford to waste food" whereas in traditional cultures and poorer communities people buy smaller amounts of food that they will cook and eat each day.

"The worst offenders are families with children in households with an income of $100,000 and young consumers between 18 and 24," says Duncan. "As a nation we throw out one in five bags of groceries, which means that 40 per cent of household rubbish is food."

But there are some simple things we can do to reduce waste and save money.

Jo Sayer is a mother of two living in Elwood, Melbourne. "I thought I was doing the right thing recycling my rubbish and throwing the food waste in the bin thinking that being biodegradable it would decompose," she says. "I was quite shocked to learn that food in landfill created methane." Sayer was filling a large black garbage sack with rubbish every week. After seeing a video produced by Sustainable Table called Waste Deep, she and her family made a few basic changes to the way they shopped and ate.

"I was buying too much food each week and wasn't using everything," says Sayer. "So I started planning meals and found I was buying less." Managing her leftover food better, storing it properly and using leftovers in other meals also helped reduce waste. She and her husband gave up buying fruit and vegetables at the supermarket, instead shopping at the local farmer's market. "Our fruit and vegetable bill has almost halved," says Sayer. They now save between  $1200 and $1500 a year on their fruit and veg bill alone.

"It's most important to stop waste at the beginning of the pipeline," says Jade Herriman, research principal at the Institute for Sustainable Futures at University of Technology Sydney. She and her team are working with Sydney Institute of TAFE to educate apprentice chefs in "root to stalk" cooking, a play on nose to tail eating, the concept in which every part of an animal is used.

"It starts with menu planning but also knowing what to do with food," she says. "In my grandparents' time food was so much more costly that food waste just didn't exist," she says. "There is still a moral dimension to wasting food – it's that we have lost or forgotten many traditional food preserving skills and ways of cooking. We want to bring back those skills such as drying, bottling, preserving and others not just to save waste but ultimately produce more creative but also more profitable chefs." Herriman and her team are taking part in Good Food Month with chef Jay Huxley demonstrating low waste cookery at Sydney Institute of TAFE on October 28 noon-2pm.

The other part of the equation is making better use of unavoidable food waste such as pumpkin peel, teabags and avocado shells.  Sayer found a solution by buying a subsidised compost bin through her local council. In it goes all the food waste, including egg shells, bones and citrus peel. "My young daughters call it the 'Green Cone Monster' and love looking into it and watching their scraps transform," says Sayer. Instead of putting a bag in the rubbish each week, now there is just one a month. "We can have it in the kitchen and it doesn't smell because there is no food in it."

Another method of avoiding food waste involves using animals as living converting units. Our family has developed an integrated waste management system that sees no organic matter hit the rubbish bin. Our two chickens eat the household scraps and any hard bits they don't eat, such as cabbage stalks, are fed to the rabbit. The rabbit in turn manures on straw in which thrives worms. The hay and the worms are given to the chickens. The chickens, in turn, manure the straw that is collected and composted with all the hard and undesirable organics such as pumpkin and potato peel. The compost is spread on to the vegetable garden and around the fruit trees. This all happens in a small back garden attached to a single-fronted Victorian terrace house .

For those who don't have space for a compost bin, there are alternatives such as the Bokashi One composting system, an airtight bucket into which scraps are added along with a mix of bacterial cultures that "ferment" the scraps without producing odours. Once broken down, the compost can be used as garden fertiliser. Another option is an upmarket mechanical biodigester called the CLO'ey. It's about the same size as a bar fridge and uses heat, agitation and heat-loving microbes to turn up to four kilograms of kitchen waste into clean, pasteurised garden-friendly compost in 24 hours. Some local councils, such as Sydney's Leichhardt Municipal Council, are beginning to offer food waste collection, where residents of flats place food waste in a container about the size of a wine cask, lined with a biodegradable bag made from starch. This goes into the communal bins and is delivered to an electricity plant, where the scraps are digested and turned into gas, which is then burned to generate electricity.

"There is no waste in nature," says Sustainable Table's Cassie Duncan. "It is a human construct." This year her organisation is pushing hard to help people eliminate food waste in their homes through their giveafork.com.au campaign. During October she and her team are encouraging Australians to learn how easy it is to stop food waste by throwing a waste-free dinner party.

When people sign up for this fundraiser they receive a free ebook full of practical ideas and tips such as cooking with beetroot leaves and potato skins. "With a little imagination you can eliminate most waste, save money and compost what's left to nourish the soil to grow more food," says Duncan. "It's a perfect circle."

What's your best tip for using up food scraps? Log in to comment below.