The milk should be heated to between 55 and 65 degrees Celsius (139 to 149 degrees Fahrenheit) for a cappuccino.
This temperature range allows the foam to be stable and milk to froth properly without scalding the coffee.
If the milk is too cold, it will not froth well and will result in a weak cappuccino.
If the milk is too hot, it will scald the coffee and produce a bitter taste.
Should Milk Be Hot Or Cold For Frothing?
Using cold milk for cappuccino is better because it froths more easily.
It also results in a more consistent texture.