Use chemical knowledge to help you analyze the coffee ingredients of individual coffee products.

Any coffee enthusiast who knows how to drink coffee knows that really high-quality coffee is not too bitter, but for most of us, most of the coffee we drink is bitter.

Fortunately, through the principles of chemistry, even laymen without professional training can make coffee of good quality! Just like adding salt to coffee can lighten the bitterness, science can help us better understand the nature of food and make the coffee in our cup tastier.

Why is coffee bitter?

It is strange that people still fail to figure out why coffee is bitter. It is true that caffeine is bitter, but because it tastes light, caffeine is not the real source of coffee bitterness. Scientists have found that coffee also contains two other bitter substances: chlorogenic acid lactone and phenyllindane. The former is abundant in light and moderate roasted coffee, while the latter is higher in deep roasted coffee. In contrast, phenyllindane is more intense, so the bitterness of deep roasted coffee is more distinct and exciting.

Can adding salt to the coffee really neutralize the bitter taste?

It has been said that adding salt to coffee can neutralize bitterness, which sounds ridiculous, but it has been proved to be effective by science. In 1997, scientists tried to put salt into a bitter chemical solution and compared the bitterness of the solution. It was found that although the concentration of bitter elements in chemical solvents did not change, the chemical solution with salt did not taste so bitter.

The ratio of coffee to water

Adding salt to coffee can only be remedied after it is lost. To really solve the problem that coffee is too bitter, we must go back to its roots. From a chemical point of view, extraction is the real source of coffee flavor. The process of extraction is so sophisticated that only by grasping it correctly can the taste of coffee become better. Among them, the first thing we need to consider is the ratio of coffee to water. In general, the ideal gouache ratio is: 60 grams of coffee / 1 liter of water, equivalent to 1 gram of coffee powder / 16 milliliters of water, or 7 grams of coffee powder / each cup of espresso.

The ratio of coffee to water is extremely important, because the more coffee, the more bitter elements are extracted. Similarly, if the water is in contact with the coffee for too long, the content of bitter elements in the coffee will increase, while if there is too much water, the coffee will be too light and thin.

Brewing time is the second problem we need to consider. We can divide the extraction process of coffee into three steps. First, the acids in coffee, that is, chemical components with fruit aroma, will be extracted first. Then comes the earthy and caramel-flavored substances, and finally the bitter elements in the coffee. Therefore, if the brewing time is very short, the content of the first kind of fruit-flavored substances in the coffee will be higher; conversely, if the brewing time is long, the content of bitter elements in the coffee will increase, accompanied by astringency.

The perfect extraction should be between the two. Of course, the ideal extraction time of different brewing methods is different. For espresso, the contact time between coffee and water should be between 20-30 seconds, while for drip coffee, the brewing time should be between 2-4 minutes.

Temperature and bitterness

Water temperature can also affect the bitterness of coffee. The ideal water temperature for brewing coffee should be between 91 and 96 ℃. If the temperature is too high, the coffee will be charred and the astringency will be stronger; if the temperature is too low, the extraction of the coffee will not be enough. Of course, there are also cases where cold brewing coffee is extracted with extremely cold water, so the bitterness of the coffee is very mild and soft, but correspondingly, this brewing method takes a very long time.

The type and degree of grinding of coffee

Even with superb brewing skills, if the quality of the coffee itself is poor, the taste of the coffee is not much better. Generally speaking, there are two kinds of coffee: Arabica coffee and Robusta coffee. Among them, Arabica coffee is of better quality and taste. Robusta coffee contains more phenols, pyrrole, sulfur and other substances, so the taste of coffee is more astringent and rough.

In addition, the degree of coffee grinding will also affect the bitterness of coffee. If the coffee powder is too coarse, the coffee will not be extracted enough, resulting in the coffee taste too light; if too fine, the extraction of soluble substances in the coffee is too high, the coffee taste will be more bitter. In order to make the perfect coffee, you must find the best balance between the two.

Milk, sugar and coffee

If there's nothing you can do, you can fix it with milk and sugar. Milk not only masks the bitterness of coffee, lactose also increases the sweetness of coffee, sugar clots caffeine molecules, and its own sweetness makes coffee less bitter.

Well, now we understand that it's not easy to make the perfect coffee. But sometimes we don't drink coffee to taste its mellow, especially when we get out of bed at 6: 00 in the morning-believe me, as a teacher, I have a deep feeling. At this time, I care more about whether there is enough caffeine than whether the bitter taste of coffee is too strong. Anyway, with the help of chemical knowledge, I believe that your coffee every morning will become both refreshing and delicious!