Sit down to a plate of freezer-burned broccoli and beef, and the experience of chewing this mummified cardboard will remind you of a basic truth: unless you store your food in liquid nitrogen, it slowly deteriorates—even in the freezer. But a new study suggests that warming up our freezers by several degrees could cut millions of tons of greenhouse gas emissions—without compromising the safety or quality of our food.
The idea of dialing down our freezers has been percolating for yeas now. A 2024 report estimated that if the worldwide standard food-freezing temperature was dialed back just three degrees, from -18°C to -15°C, the reduced energy consumption would avoid 17 million tons of CO2 equivalent emissions per year.
The new study, published in NPJ Science of Food, addresses the next logical question: whether freezing at warmer temperatures would negatively impact the quality or shelf-life of food.
The authors subjected nine frozen foods, including crispy chicken, fish fingers, salmon fillets, vegetables, pizza, and plant-based meat balls, to 18 months of freezing at temperatures of -18°C, -15°C, -12°C, and -9°C. Every month, samples of each food at each temperature were thawed and evaluated on several measures of quality, including bacterial abundance, nutrient content (vitamin C), fat degradation or rancidness, and attributes affecting palatability, including appearance, aroma, taste, and texture.
Compared to -18°C, none of the higher temperatures caused significant increases in bacterial abundance—considered an indicator of food spoilage. Meanwhile, for measurements of palatability, fat degradation, and vitamin C contents, the quality did gradually decline over time in at least some of the foods; and these declines were incrementally more rapid at warmer temperatures.
But overall, for most of the products stored at -15°C, all quality measures remained within acceptable limits until after the “use-by” date—which varies from product to product, but is generally less than 18 months.
The authors concluded that raising the standard food-freezing temperature from -18°C to -15°C was feasible, and would reduce the direct energy requirements for cooling by roughly 7 percent.
These savings may seem small on a global scale, but for nations without extensive electric grids, they could be pivotal–reducing the demands on local energy sources, such as generators, solar, and wind turbines. Combined with nascent technologies for more energy-efficient cooling systems, it could allow the global food cold chain to reach into new areas.
This could reduce food waste in local communities, where the food supply is already stretched. It could also improve the incomes of poor farmers, by allowing their crops to reach boarder, more distant markets without spoiling.
Serena, et al. “Increasing storage temperature of frozen foods: effect on sustainability and food quality.” NPJ Science of Food. 2026.
Image: ©Anthropocene Magazine
