Microwaves: FAQs
Do machines from higher heating categories cook more quickly?
Not every time – these ratings aren’t always accurate. More powerful machines don't always cook better or faster which makes the labelling scheme even less relevant.
Don't solely rely on cooking instructions
Are cooking instructions accurate?
Use the labels as a general guideline but don't take the timings on your microwave meals as the gospel truth – make sure the food is cooked until it’s piping hot throughout each time.
What do the energy labels mean?
For the past 15 years microwaves have been labelled according to their heating category from A for the least powerful, to E the most powerful. This gives consumers a rough guide about how powerful their microwave is and how long to heat food for.
We test microwaves performance against their power ratings, and have found they’re not always accurate, differences of 5-10% are commonplace. So always make sure your food is hot enough to eat before tucking in.
Can I cook several meals at a time?
Testing heat distribution in pasta
If you're heating a series of meals directly after each other, be careful to check the later meals are cooked as thoroughly as the first.
With many microwaves, as their level of work increases, the internal parts can get hot and they start to emit less power, which means you might need to increase cooking time.
Some microwaves now have shelves allowing you to cook on two levels. You need to double the normal cooking time but it's a handy feature if you want to have two meals ready at the same time.
When defrosting, should I program manually or use the auto defrost function?
Using auto defrost is easy: you simply input the food's weight and the microwave sets the best program. Alternatively, you can program the defrost yourself by setting the power level and time based on instructions in the product's manual.
Defrost slowly for best results
Success with either approach varies considerably among different machines, so try both options to discover which method works best on your microwave. In general, you might find better results programming the microwave yourself, using lower power settings and defrosting slowly.
What can I expect if I buy a budget, supermarket microwave?
Compared to pricier contenders, the cheap machines seem positively spartan. Forget about shiny silver finishes and rows of buttons and program choices.
Instead, you’ll find white boxes offering just two dial controls for setting power and time. If you can’t be bothered to decode complicated control panels before nuking your baked beans or soup then these machines already have an advantage.
They're as good as many pricier models for simple reheat and defrost tasks, but they don't have auto programs or other advanced features.
Why can't I put metal in my microwave?
Putting metal items inside a microwave risks causing sparks which could lead to fire. We run safety tests, placing a nail inside a potato to see whether any resulting flames can be safely contained within the machine, without causing damage.
Grill and combination microwaves often come with metal racks and crisping trays. These are perfectly safe when cooking in grill or conventional mode, but shouldn't be used for microwaving.
Why do instructions tell me to stir the food and let it stand before serving?
Let food stand before serving
To ensure food is safe, it needs to be heated uniformly to around 70°C. Microwaves have rotating turntables to help ensure a good distribution of rays, but they can't always penetrate every molecule and our tests show it's normal to find a spread of temperatures in different parts of the food.
Increasing the cooking time isn't the answer as it may dry out the food and spoil its texture. Instead, be sure to turn food over (top to bottom) where possible, stir it, and let it stand. Stirring helps to spread the hotter molecules around the dish while letting it stand allows the cooking to continue by conduction.
Is there a greener way to use a microwave?
Yes – some large microwaves draw quite a lot of energy when in stand-by mode. If you'd like to do your bit for the environment choose a model with an energy safe mode. This will reduce the power they use with power only being drawn for the clock.
Are there any new advancements in microwave technology?
Microwave technology is hardly a rapidly-changing area, like mobile phones and TVs. But, manufacturers still try to introduce improvements.
The Panasonic inverter
This is an attempt to make cooking on low and medium settings more even. It's a circuit board that replaces the conventional transformer and capacitor.
It controls the flow of power so that on low and medium settings the microwave cooks constantly, with reduced power, rather than pulsing on and off full power as most microwaves do.
Whirlpool’s 6th sense
This heats, crisps and steams using sensors to determine how long to cook for – real cooking at the touch of a button.