How much caffeine is in a cup of coffee? How many cups of coffee can you drink a day? How much caffeine is there in Italian and hand-brewed coffee?

As we all know, drinking a moderate amount of coffee is good for the human body, so how much is this moderate amount? According to the study, an adult's daily caffeine intake is moderate as long as it does not exceed 400mg. (of course, this amount is not absolute, after all, different people have different resistance to caffeine. ) before that, Qianjie has shared how much caffeine is in different coffees. However, as each person, each store uses different beans to make coffee, the amount of beans used is different, so it can not be generalized. Never mind! Today in front of the street to share the caffeine calculation formula of a cup of coffee, so that you can calculate the caffeine content of your own coffee!

But before that, we need to know that the release of caffeine is not something we can control during the extraction process, so the result of this calculation is only an estimate, not an absolute one! Then, to calculate the approximate caffeine content in a cup of coffee, we need to know two things about how to make this cup of coffee: the variety of coffee beans and the amount of coffee beans used.

How to calculate the caffeine content of a cup of coffee? The caffeine in coffee comes from coffee beans, and the caffeine content of coffee beans depends on its own genes and growing environment, but it is mainly affected by genes, so what we need to know is the variety of coffee beans.

(Arabica on the left and Robsta on the right) the most common varieties of coffee on the market are Arabica and Robusta. The average caffeine content of robusta coffee is about 20.4%. The caffeine content of Arabica is only 0.9% of that of Robsta. About 4%. But basically, Arabica is the main freshly ground coffee on the market because of its better flavor. Basically, no store will use Robusta when making coffee. Because of its poor flavor, Robusta is more likely to use coffee to extract more oil.

Many people may notice the degree of roasting of coffee beans, because it is widely rumored online that deep-roasted coffee has a higher caffeine content than light-roasted coffee. It would be wrong to say that the same bean changes caffeine content at different levels of roasting. Because under reasonable roasting, the caffeine content of beans will hardly change. This sentence mainly refers to the brewing level, different degrees of roasting but the same weight of beans, deep-roasted coffee will have more caffeine than light-roasted coffee, which may be true.

Because deep-roasted coffee beans are affected by roasting, the weight loss rate will be higher. The way we measure coffee is not the number of beans but the gram weight of beans, so at the same weight, deep-roasted beans may be more than light-roasted beans, so caffeine will naturally be higher. However, this is limited to the comparison of two very extreme coffee beans, and when the two roasting levels are similar, there is not much difference. Therefore, our formula for calculating the caffeine of a cup of coffee is: the gram weight of the coffee bean multiplied by the caffeine content of the coffee variety (take the average). However, the problem is not that simple. Because this formula calculates the maximum value of dissolving all the caffeine out of the coffee, and we don't dissolve all the caffeine from the coffee powder, the reason is very simple, it tastes like this.

No matter what kind of extraction method, if we want to make a cup of delicious coffee with the widest audience, then we must control the extraction rate of the coffee, followed by the concentration. Because the soluble substance of coffee accounts for only 30%, and in this 30%, a certain proportion of substances are unlikable, when they dissolve too much, they will bring bitter, miscellaneous, astringent and other negative manifestations to coffee. Therefore, generally speaking, we will control the extraction rate of coffee in the range of 18% to 22%. Also, because the molecular sizes of these soluble substances are different, their dissolution rates are not the same. Substances with smaller molecules such as acid and sweet dissolve faster and are released in large quantities at the beginning of extraction, while caffeine is a macromolecular substance. Although it is dissolving at the beginning of the extraction, the dissolution rate is very slow. Therefore, caffeine in coffee beans can not be fully extracted, nor will it dissolve too much.

With a lot of money, we can only calculate at half of caffeine. Then the formula becomes: the gram weight of coffee beans * the caffeine content (average) of coffee varieties / 2. Take hand-brewed coffee as an example, if the amount of beans used for a single cup of hand-brewed coffee is 15g, then our formula is 15 (g weight) * 1.3% (average Arabica caffeine content) / 2 (if it is only half extracted), it is concluded that the caffeine in this cup of coffee is about 97.5mg. By analogy, if 20g powder is used, the calculation formula of caffeine is 20g 1.3% / 2, which is about 130mg. (extraction time will affect the amount of caffeine dissolved. When the extraction time is too long, we can appropriately increase the content of caffeine extracted.)

The same is true of espresso, because we can only take a rough estimate, so the calculation is the same. At the same time, since most espresso is used in one serving of espresso, American coffee and lattes with a lot of milk have the same caffeine content. At this point, you can calculate for yourself how to drink coffee under the restriction of 400mg.

-END-