Here's how you dunk your biscuits like a pro - according to scientists

Dr Helen Pilcher, who has a PhD in stem cell biology, conducted an experiment to discover the optimal time to submerge biscuits in hot drinks – and at what point they reach the ‘dunking danger zone’.

She found the average biscuit should absorb 20 per cent of its original weight in liquid for the optimal dunk experience.

Milk Chocolate Digestives and Hobnobs can be dunked for just over three seconds to reach this point, while Penguin bars should remain in the hot drink for a whopping six and a half seconds. 

However, it takes a mere five and seven seconds respectively for Fruit Shortcakes and Ginger Nuts to reach the danger zone – which is when they are at risk of breaking.

But Dr Pilcher, who has been appointed by McVitie’s as their ‘chief dunking officer’ (CDO) to carry out the study, found a Chocolate Caramel Digestive can withstand an astonishing 40 seconds of plunging time before being in trouble of being lost to the depths of a cuppa.

Each of the biscuits involved in the study were dunked vertically, to its mid-point, in a mug of freshly prepared tea – with milk, no sugar – and maintained at a temperature of 60 to 65oC.