Why do bourbon biscuits have holes in them?

Have you ever wondered why the classic bourbon cream biscuit has those characteristic holes in them?

Now a biscuit maker and industry insider has revealed the tricks of the biscuit trade and why some biscuits have these hollows and why some do not.

Appearing on Channel 4’s Food Unwrapped, Mark Greenwell, the team manager at United Biscuits factory in Carlisle in North West England, which makes McVitie’s and Carr’s biscuits, said that there’s actually a vital reason why these snacks have holes in them, and others don’t.

Apparently, this is all because the small holes in the soft biscuits allow steam to escape which prevents them from breaking or cracking.A

“If the holes weren’t there, steam would build up inside the biscuits. The biscuit would collapse back down and you wouldn’t have a controllable product, he told host Kate Quilton.

“You’re trying to get steam out of the biscuits to have an even texture.”

Interestingly enough this also explains why other biscuits like ginger nuts don’t have them.

Unlike bourbons, ginger nuts are designed to snap and so steam is prevented from escaping the biscuit.

“Because the steam stays inside the biscuits, the trapped heat caramelises the sugar,” Quilton explains.

“The sugar becomes a glass like structure, like you find in a boiled sweet, and that’s what gives a ginger nut its characteristic snap.”

The United Biscuits factory makes a whopping 35 million biscuits a day at its Carlisle site. A 2015 survey found that the Bourbon biscuit was the ninth most popular biscuit in the UK to dunk into tea.