How to adjust the water temperature to make better coffee?

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Water accounts for 94-98% of a cup of coffee, but in addition, water temperature (including minerals in water) can also affect the sweetness, bitterness and sour taste of coffee.

Controlling the temperature of the cooking water is very important for people who like to flush by hand, but unfortunately, the water temperature is often adversely affected by insufficient training or the use of the wrong equipment.

To discuss the effect of water temperature on brewing, the author asked two professionals, Paul Stack, who develops a special water system for coffee and tea, and Nathan Retzer, who owns coffee shops. They mentioned the importance of accurate cooking, and here are some tips for controlling the temperature of the cooking water.

Use Marco MIX system to get temperature-controlled hot water, source: La Marzocco UK & Ireland

How does the water temperature affect coffee?

Paul: "the water temperature will directly affect the release of different substances during cooking."

There are many chemical reactions during cooking. Water will extract chlorogenic acid, acetic acid, malic acid, caffeine, oil and so on. These substances will also be released at different time points. For example, caffeine and fruit acid are released in the first part of brewing, sweetness is released in the middle, and bitterness is released in the latter part.

So what does this have to do with water? The higher the temperature of the water, the faster the substance will be released, and since each substance affects a certain flavor, the cook must carefully control what is extracted at each time.

Paul: "when the temperature is higher, it is more difficult to control the extraction. Some substances with bad taste are released quickly. Words such as too strong and scorched taste are usually used to describe this coffee whose flavor is out of control due to high temperature extraction." "

What about the low temperature?

"the best evidence is that people usually say that the cold coffee is too light because the brewing water is too low," Paul reminded me. However, anyone who has drunk it knows that cold coffee is very smooth, sweet and low in acidity. Although lengthening the brewing time can make up for the low water temperature, some substances are not extracted at low temperatures. As Paul said, "the release rates of different flavor components are different at different temperatures."

In addition, because the brewing time and grinding thickness can not fill the defect of brewing at low temperature, the brewed coffee will have a smelly sour taste and lack of alcohol thickness. Because the substance extracted is mainly acid, there is less fat to increase the thickness of alcohol, and less sweetness and bitterness to balance the flavor of coffee.

Accurate cooking is very important, and controlling the water temperature will give you a better flavor.

It is very important not only to have the correct water temperature, but also to maintain the consistency and accuracy of cooking. As Paul said, "unstable water temperature is like turning the oven on and off all the time while baking a cake, causing the oven to lose temperature, and the result will be very bad."

Bad appliances can also affect the temperature of the water.

Unfortunately, water temperature has always been a big variable, and it is impossible to completely remove it, but it can be controlled.

The appliance is also the key to control the cause. Nathan pointed out that pots with poor thermal insulation and poor heating appliances often lead to unstable results.

Paul: "the lack of hot water supply is usually the result of a lack of accuracy in temperature control, coupled with cold water pouring into the water heater at the same time." It is important to use appliances with a stable temperature of water supply. "A good machine can even make espresso of stable quality.

Nathan: "A good Italian coffee machine can accurately control the temperature, and it's right to let the water come into contact with the coffee powder." The problem with hand-brewing coffee is that you often have to add hot water to the hand-brewing pot, which will lead to a drop in the temperature of the kettle. We use Marco SP-9, an automatic hand flushing machine that can control the water temperature, so we can clearly know the water temperature when we come into contact with coffee powder.

Use Marco SP-9 hand punching machine with Kalita Wave to control the water temperature. Source: Evans Brothers Coffee

Train baristas to make the water temperature more stable

However, the point to consider is not just the equipment. "High-quality water control systems, such as Marco MIX, can accurately control water temperature," Paul explained. However, if someone pours hot water into a cold hand flushing pot or uses an unpreheated filter cup, it will cause the temperature to drop by more than ten degrees. He stressed the importance of preheating hand pots, filter cups, sharing pots and cups.

Therefore, a well-trained barista is very important, not only the process of preheating the utensils, but also related to cooking skills. The method of brewing will also affect the variation of the water temperature. if you do not keep the coffee powder wet all the time, it may be because the coffee grounds in the filter cup affect the water temperature, resulting in unstable temperature.

Formal education and training, and even participation in professional cooking courses, can help to improve the situation.

Ceramic filter cup for preheating Kalita Wave before brewing, source: Coffeewerk + Press

As long as it comes to water temperature, there are many factors that will affect the quality and stability of coffee, to ensure that you have high-quality equipment, you can accurately control the brewing factors. Set the standard procedure for hand punching. And whether it's cooking in the store or planning to take a certification exam, good training is necessary.

After all, good beans have to be washed well to give full play to their flavor.