Food scientists at the UK's University of Leeds have developed a formula for making the perfect piece of toast.
The secret to toast heaven
The equation - which details butter and toast temperature - took three months and cost £10,000 to develop.
Researchers' found that people think the perfect piece of toast should have partly melted butter patches on it, improving its taste and texture.
For this to work, the butter should be applied at fridge temperature of five degrees Celsius, the equation shows.
The formula was developed following research commissioned by the butter brand Lurpak made by Leeds-based Arla Foods.
They wanted to know how the properties of melting butter affects the taste of toast.
Spreading the word
The equation relates to the critical amount of butter, applied at fridge temperature (approximately five degrees Celsius or 41F), required to produce this effect.
H represents thickness, Cp the specific heat, P density, T the initial temperature of the toast, w the weight, and subscript a and b toast and butter respectively.
The Leeds University food scientist Professor Bronek Wedzicha translated the equation into practical terms for toast lovers.
"To produce the patches of butter most people said they preferred, the bread needs to be heated to at least 120°C, and the butter should be used straight from the fridge, applied unevenly within two minutes of the bread coming out of the toaster.
"The amount of butter should be about one-seventeenth the thickness of the bread," he said.