Journal
Steaming milk that tastes sweet
Milk gets sweeter as it warms, right up to about 65°C. Past that, it starts to taste cooked. A thermometer and your hand are all you need.
Lactose tastes sweeter when it is warm, which is why a well-steamed flat white needs no sugar. The sweet spot is 55 to 65°C: hot enough to feel, cool enough to drink right away.
Start with the wand just under the surface to stretch the milk until the jug feels warm, then sink it a little deeper to spin the milk until the jug is too hot to hold for more than a second. That second is your thermometer.