Food Waste for Thought

The Bites We Don’t Eat

Words by: Sofia Frias Graphics by: Jamie Kim

In the full-bellied moments after a meal, as the buttons on our jeans grab tightly onto their loops, we think about the food that adorned our plates. We immortalize our meals in memory, sealing them in jars that open themselves back up when called upon by a familiar smell or taste. But what about the food that doesn’t make it to our mouths? Where do the naked cobs of corn, hairpin-sized fish bones, and cores of apples end up? Surely not preserved in memory with an airtight lid. Upon deciding our stomachs are satisfied, we scrape scraps of food from our plates and into the trash. Out of sight, out of mind, right? Well, not quite. It’s rare that we worry about the impact of the food we throw out. We bite our nails over disposable straws and plastic bags, but do we ever bat an eye when tossing out a half-eaten sandwich? It’ll break down quickly enough, won’t it? Isn’t food biodegradable? Yes, it is, but that doesn’t necessarily mean it’s safe for the environment. Let’s follow our food scraps on their journey to decomposition. We start by stuffing neglected and inedible food into our trash bins until, like our pants at the end of a proper meal, the trash bag practically bursts at the seams. We twist and knot said trash bag to the

best of our ability and drag it to yet another receptacle, where it awaits its transport to the nearest landfill. It is in this landfill that, along with millions of others, our trash bag sits in a monstrous heap of waste. Once in landfills, our food decomposes through the process of anaerobic digestion, during which bacteria break down organic matter— the halved avocado that we left in the fridge for a week, for example—in the absence of oxygen. And what causes this absence of oxygen, we ask? The trash bag, which we so carefully double knotted, not only prevents our food waste from getting out, but it also prevents any O2 from getting in. Anaerobic digestion starts with bacterial hydrolysis, which converts carbohydrates, fats, and proteins into their basic components of sugars, fatty acids, and amino acids, respectively. Bacterial acidogenesis then transforms these basic components into organic acids. The organic acids are subsequently converted to hydrogen, carbon dioxide, and acetate through acetogenesis. In the final steps of the anaerobic process, through methanogenesis, methane and carbon dioxide are released. Both methane and carbon dioxide are greenhouse gasses, and in the Earth’s atmosphere, they store and emit heat from the sun, which in turn warms the planet. Methane, however, is 28 times more effective at trapping heat than carbon dioxide, and it accounts for 20% of the Earth’s warming in the last 260 years, according to National Geographic. In the simplest terms possible, methane is incredibly efficient in accelerating climate change. On a worldwide level, 30 percent of food is wasted, contributing to eight percent of all greenhouse gas emissions. explains Chad Frischmann in a Washington Post article, “The Climate Impact of the Food in the Back of Your Fridge.” While our food may only be on our plates for a few minutes, our waste lingers dangerously in the atmosphere long after we throw it away.

As we begin to feel guilty about the overripe bananas that we failed to bake into a loaf, let’s acknowledge the fact that not all the food in our trash cans goes to complete waste. Our scraps, if sorted and treated, can be broken down by machines called anaerobic digestive systems. These digesters recover methane from the anaerobic process to be used for electricity, heat and fuel, according to the EPA. The solid components left over from anaerobic digestion can be recycled as fertilizer, compost, and soil additives. Molecular components of those bananas that we were quick to throw out may eventually make their way into our flower pots. Back to our rotten leftovers. In lower-income countries, Frischamnn tells us, little waste occurs on the consumer level, as people are more likely to be frugal with what they have. In medium and higher-income countries, however, the actions of consumers and markets are the main causes of food waste. While preconsumer food waste may be out of our control, minimizing the waste of what we buy is easier than we think. After simmering the remains of last night’s roast chicken into a stock, our most practical option may be to toss it in the trash. But the leftover white rice? Throw it into a saucepan with milk, sugar, salt, and vanilla for a quick rice

pudding. Baked or boiled potatoes? Knead in flour, eggs, and oil for gnocchi from scratch. Using leftovers doesn’t always mean eating the same meal twice. For the parts of food that can’t be eaten—think egg shells, cores and peels of fruits and veggies, teabags, coffee grounds, nut shells—start a compost box. We can also reduce our waste at the root of the issue by shopping for groceries more consciously. Pints of blueberries may be buy-one-get-one-free, but are we absolutely sure we’ll finish them before they start growing fuzz? Will the 20-ounce tub of hummus start to fizz before we can chop enough carrots to scoop it up? Cheaper bulk items masquerade as good deals, but if we buy more than we can eat before our food turns, our money ends up in the trash with the bacteria-ridden blueberries. We often spend hours on our meals, dedicating time to planning flavor pairings, carefully preparing ingredients, and standing attentively before a stovetop or grill. Within these hours, we should be devoting thought and creativity to how we reduce our waste. When we put down the magazine, and pick up our next meals, we just might reserve a few seconds to change the way we interact with food after we eat it.