Which? experts have tested 22 slow cookers. These are the best three for your money - and the models that won't run up your electricity bill

The question These nifty machines make meals much more straightforward; just bung your ingredients inside it in the morning, switch it on and, a few hours later, you have a stew for supper. But when you can get a slow cooker from Asda for £18 and one from Magimix for £1,495, which are really the best to buy?

The basics Experts at Which? tested a total of 22 slow cookers: the cheapest was £25 from Daewoo and the priciest was £215 from GreenPan.

The method The whizzes at Which? assessed the slow cookers using a variety of tactics. First, they plonked a bunch of stew ingredients in each machine, ran them all for several hours on their highest and lowest settings, and then calculated every product’s energy use and running costs. They also quality-tested the finished stews, checking whether each component had been properly cooked. And, lastly, they scribbled a special ‘scratch pen’ across the inside of each cooker’s bowl, to see how scratch-resistant each product is.

The thing to remember Which? buys the products before testing them, which means no freebies and no biased results.

Find the full range of expert reviews at which.co.uk/slow-cookers

BEST VALUE

Size H 19cm x W 35cm x D 26cm 

Capacity 3.5 litres

Cable length 86cm

What works? Tiny but tough – testers found this slow cooker made great stews and was tricky to scratch. It is energy efficient, too; on the maximum setting this cost 5p an hour to run.

What’s the catch? You can only cook a stew for two to four people.

BEST MID-RANGE

Size H 22cm x W 37cm x D 22cm

Capacity 6.5 litres

Cable length 90cm

What works? This one is cheap to run, too – on the maximum setting, it costs just 4p per hour. It’s also a decent size, has a helpfully long cable and produced tip-top stews with tender meat and thick sauces.

What’s the catch? The bowl’s nonstick coating is easily scratched, so avoid using metal utensils.

BEST BLOWOUT

Size H 33cm x W 48cm x D 33cm

Capacity 8 litres

Cable length 80cm

What works? Loads. It made a first- class stew, has extra settings like ‘meat browning’ and ‘vegetable steaming’ and is a bread maker. It is sturdy, too, holds a lot and looks stylish.

What’s the catch? The price – and it costs 33p an hour on its maximum setting.