Does your milk preparation sound like the gates of hell opening? Then you're burning your milk. It not only tastes scorched, but your foam will look sad too - the bubbles burst under pressure.
Use a thermometer - the milk should be 68°C (155°F). Heat the milk until it reaches 66°C (150°F) – the temperature will continue to rise when you cut off the steam. At 71°C (160°F) the milk is burnt so keeping a close eye on that thermometer is vital. Don't leave the jug unattended with the steam wand in it. And don't run with scissors.
Reheated milk
Apart from the "sad bubble bath" appearance, you're also subjecting customers to a bacterial soup. Consider offering health insurance with every order.
Consider harsh penalties for offenders. Popular options include banishment, public flogging and trepanning.
