IT’S a mystery many people may have brooded on over their breakfast.

Now Bolton’s bread-making giant, Warburtons, has revealed just how crumpets get their holes.

The family firm appeared on Channel 4’s Food Unwrapped on Tuesday night to explain the science behind the savoury favourites.

Viewers saw celebrity chef Matt Tebbutt attempting to make his own crumpets without success.

So presenter Kate Quilton visited Warburtons’ London factory to quiz the experts.

Vasilis Nicolouzos, Warburtons’ manufacturing manager, explained how the heat of the hot plate causes bubbles in the batter to expand. The steam generated behind it then pushes the bubbles up through the batter.

"What you get is a chimney effect. Steam pushing the bubbles up causes the flutes which makes the holes in your crumpet," he said.

However, Mr Nicolouzos refused to divulge the “hole” truth and the exact length of the fermentation process remained a closely guarded secret.

A spokesman for the company said: “We are really proud to bake the best Crumpets in Britain, if not the world! Our crumpet experts work really hard to make sure each one is perfect.”