Whether customers are pleased to hear it or not, firms are selling “upcycled” food to tackle food waste internationally. Food with ingredients that were saved from the waste heap via verifiable supply chains is said to be “upcycled”. The term originated in the US, though it’s also been adopted on this side of the Atlantic. This rather broad definition includes byproducts from the food industry, such as spent grains left over from beer manufacturing, or apple pulp that doesn’t make it into juice. If you’re not familiar with the idea, perhaps you have already bought upcycled produce in the form of wonky carrots and potatoes. This is food that does not meet the visual standards of most supermarkets but is nevertheless still tasty to eat. Elsewhere, food manufacturers are making products that include upcycled ingredients. Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences. Why upcycle food in the first place? The US Environmental Protection Agency rates it as just as effective as donating or redistributing food to restaurants and shelters for reducing the environmental impact of the food system. Wasted food, after all, can generate potent greenhouse gases such as methane if left to rot in landfills. So it’s good for the planet if ingredients that would not have gone to human consumption are transformed into new food-grade products. But just how good exactly? How much of a product contains upcycled ingredients will influence its sustainability credentials. If they are listed at the beginning of the ingredients on the packaging then that indicates a large percentage of inclusion. Far down at the bottom suggests a smaller percentage. Of course, there is only so much of an upcycled ingredient that can be added to food before it affects the colour, taste or flavour of the final product. It is important to keep a balance. According to the US upcycled food certification standard, a product only needs to contain a minimum of 10% upcycled inputs by weight in order to be certified as upcycled. This may only make a slight difference to a single product’s overall sustainability. Compare it with organic food. Both in the US and in the EU, a product must contain a minimum of 95% of certified organic ingredients to be labelled organic. The EU loosely defines “organic” as food that “respects the environment and animal welfare”. This is very far from the 10% required by the certified standard for upcycling used in the US. Of course, it would be quite hard to make an upcycled product with at least 95% upcycled ingredients. Think about a biscuit. Most of the major ingredients – flour, butter, sugar – would need to be upcycled. On the other hand, would 10% be enough to encourage you to buy food certified as upcycled? Before you spend on spent grain … While I believe that attempts to include upcycled ingredients in food formulations should be encouraged, however big or small, it is important to have rules in place. In the EU, upcycled foods are not regulated and there are no certification standards, though some product packaging may claim it contains upcycled ingredients. Consumers might buy a product with a sprinkling of upcycled ingredients thinking that it is a more sustainable choice. For example, a loaf of bread recently sold in Tesco was reported to contain 2.5% spent grain by weight. In other cases, the level of inclusion appears to be quite substantial. Granola sold in Ireland claims 30% spent grain from brewers, but it is not clearly stated in the ingredient list. Often, consumers are asked to pay more for upcycled food, even though it contains ingredients that would have otherwise gone to waste. This is because the producers are often small start-ups with high production costs that they must recoup with high prices. If sustainability claims are at stake, and if consumers are asked to pay more for upcycled foods, it is important to prevent deceptive marketing that could present products as more sustainable than they actually are. One way to do so is by carrying out a life-cycle assessment, a measurement of a product’s environmental impact from its production to its disposal. The manufacturer could do this as a way of reassuring the consumer and backing up any claims with evidence. If we want upcycled foods to become more common, and so reduce waste, we have to make sure consumers aren’t being misled. If consumers trust, value and understand these products, they are more likely to succeed in the market. Don’t have time to read about climate change as much as you’d like? Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who’ve subscribed so far.