As the weather gets cooler, the demand for hot coffee is gradually increasing, and many coffee shops are pumping the milk temperature that should be around 65 degrees Celsius to nearly piping hot in order to allow takeaway customers to get a cup of milk coffee that warms their hands. So, the question is, is it good to use a latte made with unconventional milk temperature?
What will be the difference between lattes at different milk temperatures
Heating the milk to a certain temperature will stimulate lactose and increase the sweetness of the milk, which is in the range of 55-65 degrees. So, if it exceeds this temperature, will it still be able to maintain this sweetness? Or, what would be the difference in flavor with a latte made below this temperature?
Qianjie uses 40°C, 60°C, 80°C, three different milk temperatures to make a glass of milk and latte each, and the coffee beans are selected from the warm sun blend used in Qianjie stores (20g of coffee powder to extract 40ml of coffee liquid); The milk is bright fresh milk (210ml per latte). 
Mature baristas can rely on the temperature of their palms to determine when to stop whipping, and beginners can cooperate with thermometers to obtain more accurate data. 
The milk temperature of 40°C is sent to the palm of your hand and you can stop with some warm feeling;
The time to stop beating the milk temperature at 60°C is when you feel that your hands are starting to get a little hot;
The milk temperature of 80°C is a bit special, when the milk temperature reaches 70°C, even if you don't deliberately froth, the foam will still expand rapidly, and the height will continue to rise. This is followed by a rapidly rising temperature, so when it expands and rises for about five seconds, we can stop beating and the touch is very hot. Tasting time for milk
Milk at 40°C smells weaker, but the sweetness is noticeable.
The aroma of milk at 60°C is more obvious, and the sweetness of drinking is also very prominent.
The 80°C milk is full of aroma, and because the temperature is too high to taste, after the milk temperature drops slightly, the sweetness is low, and there is some milk smell.
Then the next step is to make them into lattes separately and see what the difference is.
Tasting time for lattes
40°C latte: The milk foam in the entrance is coarse, the aroma is weak, and the sweetness is more obvious.
60°C Latte: The milk foam is dense and smooth in the mouth. The flavor of coffee and milk is very balanced, and the flavor of each other is not overshadowed by each other, and it is full of sweetness.
80°C Latte: The mouth is hot, and the milk foam and the coffee underneath are in a layered state. When the temperature is lowered to 60 °C, it still has a hot mouth, and the sweetness of drinking is far less than that of a latte with 60 °C milk temperature directly, and after the temperature is reduced to 40 °C, you can drink the taste of coffee milk, but the overall taste will be relatively thin and bitter. 
From the perspective of the three temperatures, about 60°C is indeed a more ideal temperature, and the taste and flavor shown are better than the other two temperatures. And we can see that there is another advantage in this temperature range, which is that the milk foam is smooth and creamy.
Milk at 40°C does not have enough time to froth the milk, so its milk froth is the first to appear in the three temperatures. The temperature of milk at 80 °C is too high, which decomposes the protein in the milk, and the taste is not only not more prominent, but also derives a negative taste, even after cooling, the taste is far less than the first two cups.
So you know that if it weren't for special needs like takeout, most coffee shops wouldn't change the temperature of the milk in order to present a cup of latte with both color and flavor. - end -