Every home baker dreams of achieving that perfect cake crumb – moist, fluffy and full of flavour. But according to national treasure Mary Berry, the secret isn’t in a complicated technique or a rare ingredient.
The 90-year-old baking icon has shared a simple but easily overlooked tip via BBC Good Food, explaining that the fat content of your butter could make or break your bake. And it’s something many people don’t even think to check.
“The key to a light, moist cake is the butter,” Mary advises. “Always use butter with a fat content over 75 per cent.”
Even experienced home bakers can sometimes be caught off guard by a cake that emerges from the oven looking promising but tastes disappointingly dense or dry.
While it’s tempting to blame the oven, the flour, or even your measuring cups, Mary Berry says the real culprit is often hiding in plain sight.
Many supermarket butters – especially “light,” “reduced fat,” or spreadable varieties – contain a higher water content than traditional blocks. That excess water evaporates during baking, disrupting the structure of the sponge and leaving it dry or overly heavy.
“Anything below 75 per cent fat has too much water,” Mary explains. “That water evaporates in the oven, and you lose the moisture and structure you want in a cake.”
A quick check of the label can help avoid this common pitfall. Standard blocks of butter usually have a fat content around 82 per cent, but it’s easy to grab the wrong tub in a hurry. Opting for high-fat butter can make a noticeable difference, giving cakes the rich, tender texture that Berry is famous for.
Selecting the right butter is only half the battle. Mary also highlights the importance of softening butter properly before mixing.
Cold butter straight from the fridge won’t cream effectively with sugar, resulting in a batter that’s dense and uneven. Instead of trapping air – the key to a fluffy sponge – cold butter stays stubbornly clumpy.
Rather than reaching for the microwave and risking melted edges, Berry recommends a quick, fool-proof method: Cut your measured butter into cubes, place it in a bowl of lukewarm water for about 10 minutes, drain and then use as normal.
The water should be warm, not hot, and the butter should be soft but not melting. This simple trick ensures the butter is pliable enough to whip up into a light, airy base – no last-minute panic or sticky microwaved mess required.