Cookies at Which? We use cookies to help improve our sites. If you continue, we'll assume that you're happy to accept our cookies. Find out more about cookies

Burnt food could increase cancer risk

Why getting the right oven matters
Burnt toast

The FSA advises avoiding burnt toast because of its acrylamide levels

A new campaign from the Food Standards Agency has warned that eating burnt toast and overly crispy roast potatoes could pose a cancer risk. Some ways to avoid burnt food lie with the quality of your appliances.

When starchy food is fried, roasted or baked at more than 120°C, a chemical known as acrylamide begins to form as a by-product of the cooking process. Food safety experts think acrylamide could cause cancer if eaten in high enough quantities – and that you could reduce your risk by eating less burnt food.

But seasoned home chefs will know that no matter your best intentions, your dinner can turn out a little browner than expected. And even if you follow recipes to the letter, a poorly performing oven or toaster can ruin the results.

See our advice on why cooking at the right temperature is so important.

burnt cake

An inaccurate oven can sabotage your baking efforts

Is your oven overheating?

The FSA recommends that you aim for a golden-yellow colour on your roast spuds, stopping short of brown or crispy. It also says that following the instructions on the packet for oven chips will help to reduce your acrylamide intake.

With a dodgy appliance, this is easier said than done. What happens when your oven goes rogue and doesn’t behave as expected?

We’ve found that it’s more common for inaccurate ovens to surpass the desired temperature than to fall short. And it’s not just by a few degrees – 17% of all the ovens and cookers we tested in 2015 overheated by 20°C or more. 

In our latest round of tests, we came across an oven that heated food to 222°C when we set it to 180°C. That’s a shocking 42°C difference, which is likely to leave you with unexpectedly burnt bakes.

As well as an accurate temperature, consistency is important. Our tests uncover whether ovens maintain the correct temperature throughout the cooking time, and whether heat is distributed evenly inside. By baking strips of shortbread, we can see how evenly the heat has been spread out. We’ve found that it’s hard to avoid over-crisping your food in some of the worst models.

Find out more about how we test ovens to see the damage a bad one can do.

If you’re regularly getting burnt food from your oven, loosely covering bakes with foil can help, as it protects the surface of your food from more fierce direct heat. 

Avoid burnt toast

Inconsistent heat is also an issue with some toasters, so you end up with stripy toast that’s too burnt in patches. Most of us wouldn’t think twice about having a bit of over-charred toast, but this seemingly harmless breakfast staple is highlighted as a common source of acrylamide by the FSA. 

When we test toasters, we carefully analyse three rounds of toast from each model, rating both sides for a perfect golden colour – so you can tell which ones are less likely to leave you with a blackened breakfast.

To find a consistent, even toaster, check out our toaster reviews.

For more information and ways to reduce risk, consult the FSA guide to acrylamide.

More on this…