FOGO, humus and the magic in between

Compost is one of nature’s most effective recycling systems. Whether it’s created in a backyard worm farm or a municipal-scale FOGO facility, the process follows the same basic principles. Thom Fox explores how organic waste becomes nutrient-rich compost—and how you can replicate the process at home.

Compost. Organic material. Black gold. The rejuvenator of soils. The thing we rely on to live and invariably return to when we pass.

Composting has come a long way since we dug holes in the garden, buried kitchen scraps and let nature take its course. While the basic biological processes remain the same, today’s Food Organics and Garden Organics (FOGO) systems operate at a municipal scale, turning thousands of tonnes of organic waste into valuable compost products each year.

While the fundamental processes of pasteurisation and maturation behind modern composting haven’t changed dramatically, they have become more efficient and accessible, serving larger communities than ever before.

The best part? As resource recovery systems continue to improve, there is now a wealth of opportunities to engage in this beautiful process at home. Whether you have a large backyard, a small garden or simply an interest in reducing waste, there are composting solutions to suit almost any space and lifestyle.

Organics recycling at scale
If you’ve never considered starting a compost pile, bokashi bin or worm farm, now’s the time. They’re relatively inexpensive to set up, and once things are humming along, you’ve got great access to fantastic fertiliser and soil conditioner literally on tap in your own backyard.

Managing organic waste at home isn’t for everyone, however, and that’s okay too. Here in Australia, we’re fortunate to have some exemplary resource recovery systems operating at a municipal level.

The process is essentially the same whether it’s happening in a backyard compost bin or a council-scale facility. Composting relies on the right ingredients, combined with heat, moisture, oxygen and time. At a resource recovery facility, that process typically takes around 12 weeks to transform food and garden waste into nutrient-rich compost.

These world-class facilities can take your FOGO, screen it, treat it and blend it into valuable compost and soil products for landscaping projects. Before you know it, there’s a sweet-smelling, earthy and nutrient-rich addition ready for gardens, parks and revegetation projects.

Because the processes at the council and household levels are so similar, what we put in our FOGO collection bins matters.

Just like a backyard compost bin or worm farm, FOGO systems can’t break down plastics and inorganic materials—that is, things that didn’t grow in nature. As such, these items shouldn’t be placed in your FOGO bin.

So, what can go in?

Organic? Inorganic? Carbon-based? Compostable? Biodegradable? Biodegradable plastic? Bioplastic-lined products? Compostable packaging?

Confused? You’re not alone.

Fortunately, in my sixteen years working in environmental education, we’ve always come back to a simple tagline that helps determine whether something can go into the FOGO collection service—and, by extension, our at-home composting efforts: Things you eat, things that grow, pop them in your FOGO!

Think about the following:
• Dog poo*
• Plastic bags
• Glass
• Nappies
• Plastic containers

Can you eat any of these? Typically not, unless you want to end up in hospital.

Do they grow in the garden? Again, not typically.

The simple answer is that they don’t belong in your FOGO collection or your at-home compost system.
(*Note: dog and pet poo can be composted, but it is recommended that you have a separate, dedicated pet waste compost bin, and the finished product is added to ornamental gardens, not edible gardens.)

Anything else going into your organics recycling systems is costly, slows the composting process and, at worst, increases the risk of chemical leachates entering the soil as these ‘green’ packaged materials start to break down.

Pasteurisation, maturation and aerobic microbial growth
You may have heard the term ‘pasteurised milk’, but did you know the same process applies to composting at a municipal scale?

Typically, the pasteurisation process for FOGO involves organic material being placed in large in-vessel tunnels. These tunnels are constantly monitored for aeration, moisture, humidity and temperature to achieve the optimum cooking, or pasteurisation, level.

These tightly controlled conditions encourage microbial and fungal growth, which is essential to the composting process. Temperatures typically reach around 60°C–65°C, destroying weed seeds, invasive plants and many pathogens before the next stage of organics recycling begins.

The second stage is maturation.

Things just get better with time. Fine wine, good cheese, great compost.

For industry-sized facilities, the maturation stage can last anywhere from six to eight weeks. It is during this time that humus begins to take shape.

Humus, a dark, rich, moist, almost chocolate cake-like material, is a fundamental building block of healthy topsoil. It supplies depleted soils with much-needed nutrients, beneficial microbes and water-retention properties.

For best results at a municipal-scale facility, the matured compost is sifted through large trommel screeners to yield a compost blend that is roughly 4mm in size, ready to be added to large-scale landscaping and revegetation projects.

Home composting—bringing the resource recovery process to your own backyard
The exciting thing about composting at home is that you’re replicating the same process used in large-scale FOGO facilities—just on a much smaller scale.

The screening of FOGO material happens right on the kitchen bench. By making sure the things you add to your compost bins and worm farms are what we discussed earlier in this article—things you eat, things that grow—you’re encouraging the best decomposition rates for your precious resources. Anything else, like plastic containers, plastic bags and glass, needs to find a home in the general waste or recycling bins.

The pasteurisation and cooking of your organics happens in a sunny (but shaded during summer) part of your garden, where the contents are placed into a large compost bin, worm farm or, if you’re especially handy, a repurposed bathtub.

Aeration is simple too. Turn over your compost pile with a corkscrew-shaped tool called a compost aerator once a fortnight. Remember, we want the compost to stay nice and aerobic to support microbial growth.

Finally, around 18 to 20 weeks later, you can begin harvesting the microbes and humus that help support healthy topsoil.

A 4mm compost screen, reminiscent of panning for gold (and compost is, after all, a kind of black gold), can separate the finer material ready to be added to a seed-raising mix. This screened material can also be added straight to the garden as a soil conditioner and feeder.

The larger material left on top of the screener can then be returned to your compost for further maturation.

The scale may be different, but the principle remains exactly the same.

In much the same way that cars were invented as a way to get somewhere fast, we can still get to our destinations on a bicycle.

Organics recycling is much the same. We can repurpose our FOGO material at a large scale for community uptake by those who may not have the capacity or opportunity to recover those precious resources themselves. For those of us who are able to, or simply interested in, exploring the natural and ecological processes of decomposition, nothing beats collecting food and garden scraps and adding them to a thriving worm farm just outside your back door.