Here’s how to get the perfect ring doughnut. And yes, size matters

The definition of a good doughnut is not, repeat not, how much sugar sticks to your face while eating it. Turns out the secret to the ultimate doughnut is all in the squidge.


Putting her mathematical brain to good use for Domino's, Dr Eugenia Cheng, senior lecturer of Pure Mathematics at Sheffield University, has revealed that the key to sweet success when it comes to the ring doughnut is the "squidgy to crisp ratio."


She said: “We take the overall volume of the doughnut and then subtract the volume of the squidgy part on the inside, which is itself in the shape of a doughnut, with the same R (radius of doughnut) but small r (radius of dough).” 


Nope, we haven’t got a clue either. But it looks like this: 

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Doughnut formula 1

Via: Domino's /

Domino's perfect doughnut formula

So what does this mean for your doughnut-making? Well, the bigger the hole in the middle of the doughnut, the crispier it will be while the smaller the hole, the softer the inside. Got it?


See, your mum told you those maths lessons would come in handy one day.