I just discovered this simple hack to tell if you're brewing good espresso — and I wish I learned it sooner

A red smeg espresso machine with burr grinder is photographed against a blue background.

Brewing coffee is all about the science, but when things get complicated, it's nice to have a simple sensory indicator for when you're getting things right, or wrong.

That's what I do when I steam milk. At barista school, I was taught to listen for the sound of tearing paper when trying to stretch my milk. If it sounds like a screech, you're doing it wrong.