Vặn lửa xuống mức thấp vừa. Để cho sữa nguội đến nhiệt độ khoảng 41 độ C.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
This low temperature will keep your milk from heating too quickly, which in turn prevents it from burning. You want the milk heated through but you don't want it to actually boil or stick to the bottom of the pan. Watch your milk during the entire heating and scalding process. It should only take 4-5 minutes to scald. Putting freshly scalded milk in with your other ingredients could kill off yeast or actually cook eggs, which would drastically change the outcome of your baked good. It will take