The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test speed
We measure how long the hob takes to heat 1.5 litres of water to 90°C on the middle-sized burner. The quickest (excellent) hobs take less than six minutes; the slowest take more than ten minutes.
How we test simmering
We assess how well the hob can maintain a very low temperature. We aim to keep baked beans just-warm, and check to see if the hob manages this or causes the beans to dry out or harden.
How we test heat distribution
We measure how evenly heat is distributed across the burner/cooking zone. This is important when you are cooking something you cannot stir, such as a pancake. Some hobs have noticeable hotter and cooler spots that we measure using an infra-red camera.
How we test temperature overshoot
We record how quickly the hob responds when it's turned off. Some hobs - especially electric ceramic hobs - hold onto heat for a long time, whereas others cool down quickly.
How we test ease of use
We assess how easy the controls are to use and how easy the programmable features are to set.
How we test ease of cleaning
We assess how easy it is to clean the surface of the hob and around the dials. Gas hobs are usually trickier to keep clean because of the burners and pan supports.
