A rather different set of friends
There’s an important story in our rubbish bins
One of the most marvellous moments, in a truly marvellous book, is when spoiled brat Veruca Salt is pushed down the rubbish chute by Willy Wonka’s specially trained walnut-extracting squirrels. Down that chute, Mr Wonka explains, go the bad walnuts, along with potato peelings, rotten cabbages and fish heads. The Oompa Loopas expand further on the story of the rubbish chute – there, Veruca will make a “rather different set of friends”, including “a bacon rind, some rancid lard, a loaf of bread gone stale and hard”, along with “a steak nobody could chew” and “a reeky pear”.
Charlie and the Chocolate Factory - quite possibly my favourite book ever
I was reminded of Roald Dahl’s ode to food waste as I prepared a batch of vegetables for roasting. Without thinking about it, I peeled the kumara, pumpkin and parsnip. Then, looking at the pile of peelings, I realised that food waste is a more complex issue than just forgetting about a few vegetables at the back of the fridge. I was peeling those vegetables because I’d always peeled those vegetables, and I really wasn’t sure whether that was necessary.
Food waste can be divided into avoidable and unavoidable waste. Not everything we buy as food is edible – we can’t eat the shell of an egg, the stalk of a capsicum or coffee grounds, for example. This unavoidable waste is still counted in the food waste statistics, meaning that you really need to take a closer look at the numbers to understand the food waste problem. In New Zealand, around a third of food waste from households is unavoidable, and we aren’t going to eliminate this kind of waste by better storage or meal planning.
However, a survey conducted in 2015, and repeated in 2018, showed that two thirds of the food thrown away by the average household could have been eaten, at least if it hadn’t been forgotten in the back of the fridge. That figure works out to about 1.8 kilos of avoidable food waste for every household in New Zealand, every week.
If you are the kind of scientist who goes through bags of rubbish, you also make a further distinction. “A loaf of bread gone stale and hard” could have been eaten at some point before it reached that condition. Bacon rind, potato peelings and fish heads, on the other hand, are more of a grey area. Many people throw them away, but they are, technically, classed as edible, since they can be used. Around a quarter of the food that could have been eaten is classified as “potentially avoidable”, meaning that it could have been used but might have required a bit more effort, or perhaps a change of habit.
Vegetable peelings, it turns out, fall into this “potentially avoidable” category. In most cases vegetable peel is fine to eat, and I realise that I’ve been peeling quite a few vegetables unnecessarily, which means I’ve been wasting both food and the time I spent peeling them. The exception is parsnips, where it’s probably best to peel them, at least if you eat them frequently, due to the presence of naturally-occuring toxins called furocoumarins. However, I do feel compelled to point out, in case anyone is getting particularly zealous about vegetable waste, that damaged parts of kumara and parsnip, and potatoes that have gone green should not be eaten.
But the waste that households throw away, whether avoidable or not, is only one part of the story. Food is wasted at every step in the food supply chain. How much point is there in individuals trying to do a better job when every place from farms and factories to supermarkets and restaurants is wasting food? We don’t know exactly how much is wasted, but industry self-reporting suggests that it is more than 450,000 tonnes per year for all food waste sources, excluding households. But the bulk of that figure comes from agricultural and horticultural waste, classified as “food” but not actually avoidable. Avoidable food waste from the supply chain (excluding households) is around 140,000 tonnes per year, compared with around 160,000 tonnes of avoidable waste (excluding things like potato peelings) from households. This means that food waste is one area where individual action really does count.
But food waste doesn’t just contribute to climate change by squandering resources producing food that doesn’t get eaten. A big part of the food waste problem is what happens to the waste after we dispose of it. The household waste figures I have quoted are based on studies of the waste that is sent to landfill. In a landfill, organic matter such as food waste is deeply buried, which means it decomposes without oxygen. Without oxygen, decomposing food waste produces methane, and methane is a potent greenhouse gas.
Methane accounts for 42% of New Zealand’s greenhouse gas emissions, when calculated in terms of warming potential (rather than the actual volume of gas). Most of these emissions are from agriculture, but 12% of our methane emissions, and around 4% of our total emissions, come from decomposing waste. A big part of that waste is the food that we throw away in landfills. Even though it isn’t a big proportion of our total greenhouse gas emissions, it is a part that we have more control over, so it’s worth doing something about it.
For me, that’s not difficult, since I’m a keen gardener and I have both compost bins and a worm farm. There’s not much food waste I produce that can’t go in one of those. For me, the main issue isn’t disposal, but trying to prevent waste in the first place. For advice, I’ve turned to the “Love Food, Hate Waste” website. This website is part of an initiative supported by 60 councils around New Zealand, to try and tackle the food waste problem. As well as good advice on peeling (or not peeling) vegetables, the website has information about many different ways to reduce food waste, from improving food storage, to advice on meal planning. The website also has recipes that use the parts of food you might not think of eating – so if you want to make friends with the previously unwanted parts of your fruit and vegetables, that’s the place to go.
Did you enjoy this article? Subscribe now and a new article will be delivered directly to your inbox every Sunday.
The Turnstone comes out once a week. Usually, I write an original article once a fortnight and on alternate weeks I follow up with more information or some related links.
As always, let me know if you have any questions that you’d like me to answer through my articles.