Why does the coffee turn sour when it gets cold?

Many times we like three or five friends to drink coffee and chat slowly with a cup of coffee, or to get a cup of coffee and a magazine to pass the time, but will the coffee really taste good?

In fact, drinking coffee is like eating fish. Very often, a steaming fish is served fresh and delicious, but once it is cold, the smell of fish will become very strong, and coffee will sometimes be like this.

Coffee turns sour when it is cooled, because coffee beans are a fruit, so they are rich in tannins, which are released when the coffee temperature drops, and when the temperature is lower, the human taste is more sour-which may be why dry white wines must be refrigerated. So we will obviously feel that the coffee has obviously turned sour after cooling.

Of course, not all coffee will turn sour after cooling. Generally speaking, the lower the roasting degree of coffee is, the more sour it will be, while many deep-roasted coffee will not have this problem. In addition, it is said that the better the quality of coffee beans, the smaller the difference in flavor between hot and cold.

If you want to keep the coffee from becoming sour, then the best way is to drink it hot. If it is already cold, try adding some light milk or milk to make the sour taste less obvious.