Coffee powder can be boiled several times-the method of cooking coffee powder

Many friends often complain that coffee is more expensive than tea, because tea can be brewed repeatedly, but coffee can only be brewed once. There are also some friends who do not give up and extract the coffee many times. We say that this coffee can only be extracted once, but the coffee brewed after the first time can no longer be called coffee. Because there is a lot of caffeine in the brown water, or some scorched substances. We call this brown water Dirty Water. In fact, the standard black tea drinking method in the West is only soaked once, which can be clearly seen from the production process of instant coffee. Coffee raw beans are extracted in a specific container after puffing and crushing (but instant coffee is called extraction in this process) into a concentrated solution, filtered, and then dried in two forms, which is why instant coffee is divided into hot-dried instant powder and freeze-dried instant powder. At present, the vast majority of instant coffee in the domestic market is hot and dry instant powder. But in any case, the solid powder we get is exactly the solid soluble substance of coffee. The wood fiber (coffee grounds) of the crushed coffee beans has been filtered out after the preparation of the extract. So instant coffee doesn't need to be brewed. Because the solid soluble substance of coffee is easily dissolved in water. But freshly ground coffee we need to filter out the coffee grounds after the coffee is extracted. If we define "boiling" as heating the water to 100 degrees and keeping it at that temperature for a long time, then the coffee cannot be brewed. Because the source of flavor in coffee (aromatic oil) will be destroyed in the process of "boiling" at high temperature for a long time. Therefore, about 92 degrees Celsius is the ideal temperature for coffee extraction. So whether you are soaking (French pressure pot), or using a coffee machine, or siphon pot and other appliances, the water temperature of extracted coffee can not be higher than 96 degrees Celsius. So coffee can't be brewed in this sense.

In this way, in the production of filtered coffee, we can clearly see that the coffee should be brewed instead of being boiled like porridge. We use a variety of heat sources to heat only the water used to extract coffee, rather than directly boiling the mixture of boiling water and coffee powder (Turkish coffee is outside the scope of this discussion)