Question: how do you put the holes in doghnuts

Grant Campbell answered on 13 Mar 2013:

Let’s start with why do you put holes in doughnuts. As my other answers reveal, one of the things I teach is heat transfer – and the reason for the holes in doughnuts is that without them, the heat transfer to the centre is too slow, so the centre would not cook. As to how – there are three main ways: (i) loop a straight piece of dough into a circle; ii) cut out the centre of the doughnut (giving an opportunity to sell the cutouts as “doughnut holes”); (iii) deposit a circle of batter directly into the fryer.