You dipped your cookies WRONG! Scientists reveal the optimal dunking times for 10 popular varieties – and claim millions of Brits have been using the wrong technique

Dipping a biscuit into a cup of tea has to be one of life’s greatest pleasures.

But the sweet snack can turn into an unappetizing mush at the bottom of your mug if you don’t time the dunk right.

To help us out, scientists have revealed the ‘optimal dunking time’ for 10 popular biscuits, including the Digestive, Rich Tea and even the controversial Jaffa Cake.

They also estimated the “dunking danger zone”: the point at which the cookie becomes “overdipped” and begins to break or fall apart.

Most cookies only need to be dipped for a split second – sometimes called “the microdunk” – and most of us have been dipping our cookies for too long, they say.

The research was commissioned by biscuit manufacturer McVitie’s, which has appointed British scientist Dr Helen Pilcher as chief dunking officer (CDO) as part of a promotional campaign.

According to experts, 77 per cent of Britain’s 2,000 adults have lost a biscuit in a drink due to ‘over-dunking’, leading to an estimated loss of 6.1 million biscuits every week.

‘The natural porosity of a biscuit makes it an ideal snack to dip into a drink and enjoy all the deliciousness,’ says Dr Pilcher.

‘However, Brits are still sensitive to dipping their biscuits too thinly. That’s why we’ve mapped out the optimal dunking time and the danger zone for dunking for a series of McVitie’s classics.

“Each cookie is unique in texture, structure, flavor and size, and all of these factors influence its likability.”

Together with McVitie’s staff, Dr. Pilcher conducted weeks of experiments in the laboratory to see how long the cookies lasted before disintegrating, plus their weight before and after dipping.

Each cookie was immersed vertically, up to the center, in a mug of freshly prepared tea (with milk but without sugar), which was kept at a temperature of 60°C to 65°C.

The experiments showed that the ‘optimal dunking time’ occurs when the cookie absorbs 20 percent extra weight and is at its best in terms of both taste and structure.

So this is the point where it takes over the flavor of the tea, but still retains a bit of bite.

For six of the ten cookies, the optimal dunking time occurred at less than a second.

The experts discovered that the Ginger Nut and the Fruit Shortcake have the shortest optimal dunking time: just 0.3 seconds.

This was followed by the Digestive (0.4 seconds), Hobnob (0.5 seconds) and then the Rich Tea and Jaffa Cake (both 0.6 seconds).

Essentially, this is such a small difference that the dunking shouldn’t vary too much depending on which of the above cookies you have.

Just make sure you do a ‘micro-dunk’: in and out quickly.

However, the optimal immersion time becomes significantly longer if you opt for a chocolate-covered variety, the experts found.

This is because the chocolate provides a ‘protective coating’ and makes it harder for the porous cookie to absorb liquid.

Dipping a chocolate-covered cookie essentially means you don’t have to rush your dunk so quickly.

The optimal immersion time was 3.6 seconds for Milk Chocolate Digestive, 3.7 seconds for Milk Chocolate Hobnob and 5 seconds for Chocolate Caramel Digestive.

Finally, there was the Penguin (6.5 seconds), which benefits from a protective chocolate coating around the entire surface, rather than just on one side like the others.

Although the Jaffa Cake has a chocolate layer on one side, the optimal dipping time is shorter than other chocolate-covered cookies due to the fragile biscuit base.

In reporting its findings, McVitie’s admitted that ‘Jaffa Cakes are not biscuits’ because they have a highly porous sponge base, which absorbs liquid quickly.

Dr. Pilcher and colleagues emphasize that the optimal dipping time is different from the dipping danger zone – when the cookie actually starts to fall apart.

Fruit Shortcake and Ginger Nut break apart at 5.3 and 7.3 seconds respectively, followed by Rich Tea (8.8 seconds), Jaffa Cake (9.2 seconds) and Digestive (11.2 seconds).

Amazingly, at the bottom of this list was the Penguin, which can withstand an impressive 540 seconds (nine minutes) underwater before falling apart.

If you pass the danger zone, your snack will turn to brown mud at the bottom of the mug – so make sure you have your stopwatches ready to make sure you don’t reach it.

“It is critical not to dive beyond the danger zone,” Dr. Pilcher warns.

“It is total madness to enter this structurally dangerous area.”