Iceland reveal formula for perfect chip butty

By on Friday, March 4, 2022

Dr James Hind, a statistician from Nottingham Trent University, developed a formula based on survey findings from 2,000 Brits as to how they most commonly create a chip butty.

The academic then experimented around the most popular methods with timings, temperatures and, crucially, portion sizes to refine his recipe.

The survey for Iceland supermarket found that the bread for a butty must be a sliced white loaf, preferred by over half (52%).

• Just 14% favour a soft bread roll; 9% a bap; and 8% sliced brown bread.
• It should be a medium sliced loaf (49%) rather than thick sliced (26%) or thin sliced (7%).
• The bread must be buttered (65%) rather than relying on margarine (23%) or any other spread and a thin layer of butter is best (64%).
• The chips should be thick cut (46%) like those from the local chippy rather than standard oven chips (33%) or skinny French fries (11%).

Brits most commonly choose to use only seven or eight chips (37%) in their butty.

But after experimenting, Dr Hind concluded that we are blundering by using 50% too few chips – and proposes 12 as the perfect number.

He says the optimum ratio of chips to bread by weight is three quarters, adding the weight of any ketchup to that of the bread.

On that basis, a layer of 12 chips weighing around 60g should go between two 40g medium slices of white bread.

Any less than that ratio and Dr Hind warns that there may be insufficient chips to melt the butter, which is required to soften the bread and create a tasty contrast to the crispiness of chips.

Too many chips and it will be awkward to eat the butty and every mouthful will seem like it is almost all chips with the bread and butter going largely unnoticed, Dr Hind concluded.

His equation for the optimum ratio of chips to bread is:

C ≥ 3b/4 + k + 3m, where C is the weight of chips(g), b is the weight of the bread(g), k is the amount of ketchup (ml) and m is the mass of butter (g).

Dr Hind said: “What makes white bread preferable is that it is usually the softest. This makes it a perfect contrast to the crunchy chips. And sliced bread has a constant thickness, giving a more consistent chip butty. The most important thing is to have the weight of chips at least three quarters of the weight of the bread plus ketchup. But every type of bread and style of chip varies subtly, so I’d encourage people to experiment at home and devise their own perfect formula. Personally, I much prefer brown sauce and you can substitute it for ketchup in the equation as you like. One thing my formula ignores is salt. That’s a matter of personal taste – and personal health – and so that’s a great place for people to start their own experiments!”