Does water temperature matter when coffee is extracted?

In the brewing process, water and coffee will undergo some complex chemical reactions, and the water temperature will directly affect the extraction rate of different components in the coffee during brewing. Water extracts quinic acid, amino acids and tannins, caffeine, oils and other substances from coffee. During the cooking process, different stages produce different reactions.

The temperature of the water affects the quality of the coffee liquid extraction, but the reason why it is good or bad cannot be attributed to the water temperature, but to the brewer's ignorance of coffee. As the saying goes, "it is not the knife, but the person, who knows nothing about coffee." water is just a tool to be used.

Brewers had better have a certain degree of understanding of coffee itself (through the accumulation of their own experience or information in books). According to its variety and origin, there will be differences in flavor, and its baking degree determines the promotion and retention of flavor. Then synthesize the above two points, and then according to the size of its ground beans to determine two points:

The level of "brewing water temperature" and the length of "brewing time"

Too high water temperature will cause the coffee to become very bitter, and the flavor will be messy, while the lower temperature will cause the coffee to be very sour and a little astringent.

In the case of high temperature, the aroma of coffee will be destroyed, resulting in bitter extraction; of course, this is not uniform; Japanese flannel punching method is high temperature, stirring method is also high temperature; it depends on the baking degree of beans and auxiliary extraction, if slightly shallow beans are roasted, using high temperature will really be destroyed; and excessive extraction

On the other hand, it is difficult for you to eat the contents of the cup extracted at high temperature. If the temperature is low, the water can not penetrate the body of coffee beans, thus causing insufficient extraction and only a sense of acidity, but some people can also extract good flavor with 60 degrees water of freshly baked coffee beans.

In addition to not considering special factors and auxiliary extraction; the higher the water temperature, the easier it is to over-extract; while the lower the temperature, the easier it is to underextract, which, of course, depends in part on the baking degree and freshness of the beans.

If the water temperature is too low, it will cause insufficient extraction and make the coffee tasteless. If the temperature is too high, the coffee will have some bad taste. If you like to cook coffee by hand, the first thing to do is to boil the water. The temperature of the water depends on your professional experience. Barista training said that when the water is poured to a certain extent, the heat source should be turned off, and then let the water cool for about a minute before the coffee liquid is extracted. After brewing ordinary coffee beans, drink them while it is hot, because the taste will change if it is cooled, and it will be more delicious when there is no hot drink. When pouring the brewed coffee liquid into the coffee cup, be sure to warm the coffee cup in order to keep the coffee temperature longer. At the moment of pouring the coffee liquid into the coffee cup, the aroma of the coffee is given off bit by bit, so finish the coffee before the taste of the coffee completely disappears.