3 ways to compost your food waste
Did you know, globally, roughly one third of the food produced for human consumption every year gets wasted? That’s approximately 1.3 billion tonnes worth of food waste that ends up in landfill emitting harmful greenhouse gases.
Food wastage occurs throughout the entire food supply chain – from fruit that is discarded when harvested due to supposed “flaws”, to the wilted spinach that you throw into your bin at the end of the week.
Not only is the food itself wasted, so to is the labour, water, energy, land and other natural resources that went into producing that food in the first place.
While as consumers we may be somewhat limited in what we can do to reduce food waste further up the chain, when it comes to reducing that waste in our homes, we can certainly take steps to reduce it.
These include meal planning, storing food correctly so it doesn’t go off, ensuring all leftovers get eaten, and eating veggie and fruit parts you may never have thought of consuming before.
Even if you’ve managed to reduce your overall food waste in your home you will still need to dispose of food scraps at some point.
There are essentially three ways of doing this – with a bokashi bin, a worm farm or a compost bin.
Alternatively, you can download the ShareWaste app, or find out whether friends or family compost and are happy to take your food scraps off your hands. Some councils have also started to offer combined food and garden waste collections. Check your council website to see if your council offers one.
A Bokashi bin
When I began my zero waste journey I initially invested in a Bokashi bin, but quickly discovered that with our family’s diet largely made up of wholefoods, it would fill up fairly quickly (more on that later).
A Bokashi bin is an airtight composting solution. The bin can live under your sink or on a balcony so it’s great for smaller homes.
You add food scraps to the Bokashi bin (which is basically an air-tight bucket) in a 3-4cm thick layer before adding a few sprays of liquid bokashi. The micro-organisms in the liquid ferments the food waste and prevents it from putrefying.
During the fermentation process, the waste reduces in volume due to its water content draining to the base of the bucket. This liquid can then be easily drained through the tap and used as a nutrient-rich fertiliser for the garden.
When the Bokashi bin is full, let it sit for a couple of weeks, then the contents will need to be buried or added to a compost bin.
When I was exclusively using a Bokashi bin we were living in an apartment at the time so disposing of the fermented food waste required some thought.
I used the ShareWaste app to locate a community garden nearby but found I was making frequent trips to the garden and quickly realised we needed a composting system that could handle our food waste output.
Initially, I thought upgrading to a Hungry Bin worm farm would render the Bokashi bin useless but we now use both systems simultaneously.
The Bokashi is great for onion, garlic and citrus scraps. I also use it if I’ve done some batch cooking and have more scraps than usual which the worms may not be able to keep up with. Having moved from an apartment to a house we can now bury the Bokashi bin waste in our backyard.
A worm farm
We upgraded to a Hungry Bin worm farm about five months ago. This has been a great way of not only disposing of our food scraps, but also cardboard, egg cartons, (non-glossy) paper, vacuum dust and dry leaves.
To set up the worm farm (which looks just like a regular green bin) I bought a big bag of potting soil, a bag of 2,000 worms and a couple of hessian bags (to keep the worms warm and snug).
I tipped it all in, let the worms get accustomed to their new digs for a few days, and then very slowly started to add food waste over the next few weeks.
We now have a healthy colony of worms that will chow down on up to two litres of food waste per day, and will produce liquid fertiliser and castings that can be used on our garden.
It’s important to have the right ratio of carbon or “browns” (paper or cardboard, dead leaves, sawdust or wood shavings, egg shells, old grass clippings, hair and nail clippings) to nitrogen or “greens” (food) for the bin to be effective. The ideal carbon to nitrogen ratio for a worm farm is 20:1.
While for the most part our worm bin has been a fairly straightforward system to maintain, we have had times where other insects have set up residence (fruit flies and… urgh gross!… maggots). We just added some extra carbon and cut back on the food scraps for a week or two until the bin returned to balance.
A compost bin
A compost bin is the most traditional way of disposing of food waste. You can either purchase a ready-made compost bin (or tumbler), or build your own.
You’ll need to pick a good location in your backyard for your compost bin, one that is protected from the wind, close to a water hose, and has a good drainage system so that the bottom of the pile doesn’t turn soggy.
Once your bin is set up, start by adding a large layer of “brown” material as the base, then begin to alternate your layers between “green” and brown. Always cover your green layer with a brown layer immediately to avoid it emitting odours.
The contents of your compost bin will need to be “turned” regularly. You can do this by using a pitchfork to aerate the pile every day or two.
If you’re ready to start giving composting a try a good resource to check out is the Compost Revolution website. The site features general advice and tutorials on the three composting methods discussed above, as well as discounts on composting products.