The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test cooling power
We test cooling power by seeing how quickly a fridge chills, as the faster food cools the longer it will last, the more nutrients it will retain and the less chance there is for harmful bacteria to thrive.
How we test accuracy of thermostat setting
To see whether you can rely on a fridge's thermostat to create perfect temperatures for storing chilled food, we set the fridge up following the manufacturer's recommended thermostat setting. Models scoring five stars have reliable thermostats that are spot on, whereas for models scoring two stars or less you would need to set the temperature using a separate fridge thermometer.
How we test temp stability in a hot room
We test how closely the fridges maintain the correct temperature when the room temperature rises, just as it does in your kitchen at home during a heatwave. We do this by turning the temperature in our test chamber up to 35°C and testing the temperature of the food-equivalent gel packs. Five stars means the gel packs stay perfectly chilled, which is what you want for your food. But two stars or less means the gel packs either warm up or become too icy in the fridge compartment.
How we test energy efficiency
How energy-efficient the fridge is for the amount of usable space it offers. Fridges are switched on 24/7, so it's important to choose one that won't cost a fortune to run. The best fridges score four or five stars and use a minimal amount of energy to cool food. You can spot the real energy guzzlers as they're awarded a poor one or two stars in this test.
How we test quietness
We assess how noisy each fridge is when the compressor's running and when it switches on and off.
How we test ease of use
To see whether a fridge is easy to use, we rate aspects such as how sturdy the shelves and drawers are, how smoothly the drawers slide in and out, whether there are enough door racks and shelves for the size of the fridge, whether the fridge is easy to programme and whether the thermostat is easy to adjust.
How we test ease of cleaning
We spray cherry juice inside each fridge, let it dry to a sticky mess and then rate how easy it is to clean, to see how likely food and drink spills are to seep into hard-to-reach spots and crevices.
