The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test chopping
We test how well each food processor chops, taking into account preparation time as well as the evenness and fineness of the finished result. To test how well each model handles different food types, we test each model with onions, nuts and herbs - the best food processors work well with all three.
How we test pureeing
We check how well food processors can puree baby food - we check whether the bowl or jug needs scraping down in order for all of the ingredients to be pureed properly and whether the puree is smooth and even. We also sieve it to check whether it contains any lumps.
How we test assembly
We check how each it is to assemble each food processor, assessing how each it is to set up and use as well as whether it's tricky to fix or remove the machine's attachments.
How we test quietness
Food processors can be loud, so we give a subjective rating for how quiet each model is while its in operation.
How we test cleaning
We check how easy each food processor is to clean, taking into account whether the body of the machine is easy to wipe down, how easy the attachments and accessories are to get clean and whether any supplied parts are dishwasher safe.
How we test grating
We assess how well each model grates both hard and soft food. We take into account the yield and evenness - the best models will grate all of the food (rather than leave chunks ungrated) and will deliver even results. Each machine is tested with both cheese and carrots.
How we test slicing
We test how well each food processor slices, taking into account both yield and the quality of the slices. The best food processors will slice all of the food (so there won't be any chunks leftover) and the slices will be even. To see how well each model works with both hard and soft food, we test them with both carrot and cucumber.
How we test mixing
We check how well each food processor mixes cake batter, timing how long it takes to mix in all of the ingredients and checking whether they are all well incorporated and how often the bowl needs to be scraped down in the process. We also check how much the cake batter increases in volume after baking - a greater increase suggests a well-mixed batter.
How we test kneading
We assess how well each food processor kneads bread dough, timing how long it takes for it to be kneaded, how even it is in consistency and how much the dough increases in volume. We then bake the dough to check whether the bread has any large air holes - a sign of uneven kneading.
