Morrisons has this month turned the freezers up in 10 of its stores. The change from -18°C to -15°C saves a significant amount of energy and reduces greenhouse gas emissions, but with “no impact on food safety”, the supermarket chain said.
Research published last year showed that raising the temperature of frozen food by just 3°C could safely reduce food loss and cut 17.7MtCO2e a year. “The standard temperature of -18°C was decided 93 years ago and has not changed since, so we have an inbuilt process of ‘over-freezing’ food,” said Leyla Sayin from the University of Birmingham, which led the research with the Paris-based International Institute of Refrigeration, and London South Bank University.
Morrisons said freezers have improved considerably, while modern technology and monitoring provides a precise picture of frozen food temperatures throughout the supply chain. Using a higher temperature of -15°C can also make freezing food at the point of harvest easier in hotter climates; it would also be easier to maintain during transportation.
Morrisons said the temperature change will help achieve its target of net-zero operational emissions by 2035. The chain’s operational emissions (scope 1 and 2) stood at 548,655tCO2e in 2022/23, down 15% on the previous year. These account for just 3% of its total emissions, which amount to around 20.5MtCO2e, according to an analysis by The Grocer in 2022.
Higher temperatures for freezing also reduce costs. The plan is to roll this out to all Morrisons stores and the frozen supply chain. “[…] we will be encouraging our suppliers and partners to do the same,” said corporate services director Ruth McDonald.
Morrisons is one of a growing number of companies to have joined the Move to -15°C initiative, launched at COP28. Signatories include Nomad Foods (the company behind brands like Bird’s Eye, Findus and Iglo), as well as Danish Crown and the British Frozen Food Federation.
