When steaming milk, you want the temperature of it to be between 155 to 165 degrees F. This can be tracked by using a beverage thermometer (affiliate link). Don't be in a hurry to reach that ideal temperature, though! You want to go low and slow when heating the milk to allow the sugars to come out in the milk, giving it the sweet taste we're looking for! If the milk is heated too fast, it will burn and result in terrible-tasting steamed milk!