Milk first or milk last in tea? What the 75°C line really means

Milk first or milk last in tea? The argument rests on one number: milk proteins change shape above about 75°C. This piece explains where that figure comes from, who says what (a Loughborough chemist, the UK tea industry and the ISO tasting standard), and lets you pour a virtual cup both ways to see how the order changes what temperature the milk sits in.

It is a simplified model, not a verdict, and it also covers the brew time and water that matter far more than the order of the pour.