Scientists find the formula for the perfect bacon butty

It is N = C + + fb (Ts) + fc . ta.

Scientists claim that this formula for cooking time and temperature will produce the crunchiest of results.

And that, according to their research, is the most crucial characteristic in a lip-smacking sandwich.

The experts at Leeds University tried 700 variations on the traditional bacon butty.

They used different types and cuts of bacon, cooking techniques, types of oil and a range of cooking times at different temperatures.

A shortlist was tested with computers to measure the texture of each sandwich, and then given to 50 volunteers to rate.

The results, according to team leader Dr Graham Clayton, showed that a crispy filling was the key.

"We often think it's the taste and smell of bacon that consumers find most attractive," he said.

"But our research proves that texture and the crunching sound is just - if not more - important.

"While there was much debate within our taste panels on the smoked or unsmoked decision,

everyone agreed that tough or chewy bacon is a turn-off."

For the mathematically challenged, the formula for perfection uses two or three back bacon rashers, cooked under a preheated oven grill for seven minutes at around 240c (475f).

The bacon should then be placed between two slices of good quality bread, which should be 1cm to 2cm thick.

Out of interest, N = force in Newtons required to break the cooked bacon. C = Newtons required to break uncooked bacon, fb = function of the bacon type, cm = cooking method, tc = cooking time, Ts = serving temperature, fc = function of the condiment/filling effect and ta = time or duration of application of condiment/filling.

Afficionados of the bacon butty may feel the scientists failed to answer some of the most important questions of all.

Though they did include sauce application in their formula, the team did not rule on the best flavour - tomato ketchup, brown sauce or a dollop of mayonnaise.

And is it best washed down with a cup of tea, a freshly brewed coffee or some other form of refreshment?

This is not the first time scientists have calculated a formula for everyday tasks.

Food scientist Dr Len Fisher, of Bristol University, paved the way by producing a formula for dunking a chocolate digestive in a cup of tea.