What degree of water should I use to make coffee by hand? What is the right water temperature for hand-brewed coffee?

Water temperature is another variable that is frequently mentioned in addition to the degree of grinding when people communicate their cooking experiences daily. Whenever a guest and friend asks about the water temperature used to brew coffee on Qianjie, Qianjie will always throw out such suggestions as "Deep roast coffee is 86°C~89°C, light roast coffee is 90°C~93°C." This puzzled many friends, because the water temperatures used by some competition players or coffee gods they knew were outside this range. Some are 94°C, some are 95°C, and some are even higher. So, yesterday, a guest friend asked Qianjie this question: "Why is the water temperature different when everyone makes coffee? What temperature is the best coffee brewed? "

This is a question that many friends ask when they first start! To know the answer, we need to first understand how water temperature affects coffee extraction.

Effect of water temperature on coffee extraction The essence of coffee extraction is a process that uses water as a solvent to dissolve soluble substances in coffee powder. The temperature of water can determine the rate of dissolution of substances during the extraction process, because the thermal motion (kinetic energy) of water molecules will strengthen as the temperature increases. Therefore, when the water temperature is higher, the faster the material dissolves, and when the water temperature is lower, the slower the material dissolves.

Here is a common example in daily life: When we brew granules or instant coffee, if boiling water is used for brewing, most of these granules will dissolve quickly in a short period of time; If warm water is used, although a small part will dissolve after coming into contact with water, most of the other granules will need to be stirred with the help of a spoon to fully dissolve; But if you use cold water to brew it, even if you use a spoon to stir hard, it may not be completely dissolved. Through this example, we can intuitively see the impact of water temperature! Therefore, it can be known that water temperature affects the extraction efficiency of coffee. If the objects we brew are like granules or instant dissolving these refined substances, the water temperature can actually be as long as these particles can melt in the end. Even if you use a water temperature of 100 ° C to soak, there is no problem. On the contrary, the faster the better, it's just a little hot for your mouth. (Sugar: Pretend to be a granule)

However, the extraction of coffee cannot be relatively arbitrary. Because coffee beans not only contain pleasing and excellent flavor substances, but also contain some unflattering substances such as bitter, miscellaneous, and astringent. If we want to brew a delicious cup of coffee, we must reasonably control the extraction parameters to try to avoid dissolving (or covering) those unlikable substances. The extraction efficiencies that coffee beans with different characteristics can adapt to vary, and the core parameter that can affect the extraction efficiency is not only water temperature, but also grinding degree, water volume, and time. So although it is feasible, Qianjie does not recommend using hot water at a certain temperature to brew all coffee, because this will have very high limitations and workload.

So if we want to find a water temperature that can be used to make the current coffee, the Front Street Association recommends that everyone first fix other extraction parameters: grinding, time, and water volume. Then try using different water temperatures one by one, and finally find the best water temperature that is most suitable for brewing the current coffee based on the taste. But try not to let the water temperature fall below 84°C, because the extraction efficiency is too low and it is difficult to dissolve the substances in the coffee. Take Qianjie as an example. Everyone can refer to the ideas. The dozens of beans in Qianjie Bean List are divided into two categories by Qianjie: deep-roasted coffee and lightly roasted coffee. When designing the brewing plan, whether it is deep baking or light baking, all parameters except the extraction water temperature are the same. The grinding is 80% of the screening rate of No. 20 sieve (but because the crispness of the beans is different, the scale used when grinding will be different), the extraction time is 2 minutes, and the ratio of powder to water is 1:15, and then the temperature is used to brew with hot water.

The final result is the two parameters listed at the beginning of Qianjie: deep-roasted coffee is 86°C~89°C, and lightly roasted coffee is 90°C~93°C. These two are the water temperature parameters that are most suitable for the current formula (i.e., 80% sieving rate of No. 20 sieve, extraction time of 2 minutes, and powder-to-water ratio of 1:15). You can also find out the water temperature that suits you in the same way, because the bean grinder used by everyone may not be the same, so even if the beans are the same, the size of the ground particles will be different. Having said this, I believe everyone can understand why players on the field use water temperatures of 94°C, 95°C, or even above to brew coffee. This is closely related to the coffee beans they use and other parameters.

Of course, we can also find the appropriate abrasive degree parameter by reversing the fixed object. For example, fix all other parameters other than grinding, and then find the right grinding based on the taste. But as Qianjie mentioned earlier, more details need to be paid to when adjusting grinding, because Qianjie mentioned it in detail before, so I won't go into it here. Finally, it should be noted that the water temperature we are discussing now refers to the water temperature in the pot, that is, the water temperature of the hot water in the hand-brewed pot rather than the water temperature at which it actually comes into contact with coffee grounds. After hot water is injected from the mouth of the pot, it will be absorbed by the surrounding air, filter cup, and coffee powder. The water temperature of the coffee powder extracted will be lower than the water temperature in the pot.

Some friends may think that this is not something worth noting, but it is the opposite. Because if you don't pay attention, it will intensify the loss of water temperature and reduce the extraction efficiency of hot water. For example, when you use a ceramic filter cup to make coffee, without a warm cup, the ceramic filter cup will absorb more water temperature to fill itself; or many friends will like to increase the water injection height to increase the impact of the water flow., in order to improve extraction efficiency. But when the height is too high, it will cause the hot water to lose more temperature/extraction efficiency due to coming into contact with more air.

Therefore, in addition to the water temperature in the pot, we also need to pay attention to the water temperature in contact with coffee powder. Although there is no need to go to great lengths to measure the water temperature in the powder layer, the height of water injection should be controlled (this is the most important factor in the water temperature), and the height of water injection should not exceed the height of a fist. This can effectively prevent the hot water from being extracted too much and causing extraction deviations.

- END -