Guinness drinkers with moustaches are unknowingly wasting an estimated 162,719 pints every year by trapping it in their facial hair, scientists claimed yesterday.

Research commissioned by the brewing company found that the average moustachioed tippler traps a pint and a half of the creamy liquid above their top lip annually, leaving them with an additional moustache tax of up to £4.58 a year.

With an estimated 92,370 drinkers with facial hair in the UK, who consume on average 180 pints each a year, the total cost of wasted Guinness works out at £423,070.

Robin Dover, a specialist in hair science and dermatological conditions, was called to explore the full extent of the loss. He spent two days analysing the Guinness soaked moustache hair of eight human guinea pigs, using a pre-weighed tissue and a set of super accurate scales. While the hair itself is capable of absorbing 20% of its own weight in liquid, Dr Dover observed that the majority of the wastage occurred between the fibres of the facial hair.

The scientist found the average drinker takes 10 sips to sink a pint, of which 0.56 millilitres of Guinness is trapped in the average moustache at every sip.

An estimated 162,719 pints are lost in total a year by drinkers with moustaches, meaning if every one of the 1.8 million men in the UK today with facial hair drank a pint of Guinness, the total loss in just one sitting would be 17,684 pints.

As the data was based on the average moustache surface area. Scientists were able to work out the amount of wastage depending on size, shape and density.

The WG Grace walrus moustache involved an annual wastage of £27.48 a year.

The Des Lynam-style loses around £12.59 a year because of its density, while the carefully manicured George Michael costs £9.16 per year in wasted Guinness.

But a more wasteful type of facial hair is the Noel Edmonds.

The moustache has the added complication of a full beard to collect residual overflow, which adds up to £22.90 in lost Guinness.