How Much Caffeine is in a Cup of Coffee? How Many Cups Can You Drink Per Day? How Much Caffeine is in Espresso and Pour-Over Coffee Respectively?

Understanding Moderate Coffee Consumption and Caffeine Intake

As is well known, moderate coffee consumption is beneficial to human health. But what exactly constitutes "moderate" consumption? According to research reports, as long as an adult's daily caffeine intake does not exceed 400mg, it is considered moderate. (Of course, this amount is not absolute, as different people have varying tolerance to caffeine.)

FrontStreet Coffee's Guide to Calculating Caffeine Content

Previously, FrontStreet Coffee shared the approximate caffeine content in different types of coffee. However, since the beans used and amounts vary by individual and coffee shop, it's not possible to generalize. Not to worry! Today, FrontStreet Coffee will share a formula for calculating the caffeine content in a cup of coffee, so everyone can calculate the caffeine content of their own homemade coffee!

However, before that, we need to understand that caffeine release is not something we can control during the extraction process. Therefore, the calculated results are merely estimates rather than absolute values! Then, to calculate the approximate caffeine content in a cup of coffee, we need to understand two key pieces of information about the coffee: the coffee bean variety and the amount of coffee beans used.

How to Calculate Caffeine Content in Coffee

The caffeine in coffee comes from coffee beans, and the caffeine content in coffee beans depends on their genetic makeup and growing environment, but is mainly influenced by genetics. Therefore, we need to understand the coffee bean variety.

(Left: Arabica, Right: Robusta) The most common coffee varieties on the market are mainly Arabica and Robusta. The caffeine content in Robusta coffee averages around 2-4% of its weight, while Arabica's caffeine content is about half that of Robusta, only around 0.9-1.4%. However, basically, freshly ground coffee sold on the market mainly uses Arabica because of its superior flavor. Basically, no shop would use exclusively Robusta when making coffee because of its poor flavor. Robusta's primary use is as an auxiliary to extract more oils from coffee.

The Roast Level Factor

Many people may notice the roast level of coffee beans, because there's a popular online belief that "dark roasted coffee has higher caffeine content than light roasted coffee." If this statement refers to the same bean having different caffeine content at different roast levels, then it's incorrect. Because under reasonable roasting conditions, the caffeine content of the beans barely changes. This statement mainly refers to the brewing level - when brewing beans of the same weight but different roast levels, it might be true that dark roasted coffee has higher caffeine content than light roasted coffee.

This is because dark roasted coffee beans, affected by roasting, have a higher weight loss rate. And the measurement method we use for making coffee is not the number of coffee beans but the gram weight of the beans. Therefore, at the same weight, there might be more dark roast beans than light roast beans, so the caffeine will naturally be higher. However, this is limited to comparisons between two very extreme coffee beans. When the roast levels are similar, the difference is actually not significant.

The Caffeine Calculation Formula

So, our formula for calculating caffeine in a cup of coffee is: coffee bean gram weight multiplied by the caffeine content of the coffee variety (using average values). However, the problem isn't that simple. Because this formula calculates the maximum value of all caffeine in the coffee being dissolved, and we don't dissolve all the caffeine from the coffee grounds. The reason is simple: it wouldn't taste good!

Understanding Extraction Rates

Regardless of the extraction method, to make a delicious coffee that appeals to the widest audience, we must control the coffee's extraction rate, followed by concentration. Because only 30% of coffee is soluble, and within this 30%, there's a certain proportion of substances that are not desirable. When they dissolve excessively, they bring negative characteristics like bitterness, impurity, and astringency to the coffee. Therefore, we generally control the coffee's extraction rate between 18-22%. Additionally, because these soluble substances have different molecular sizes, their dissolution rates are not the same. Smaller molecules like acids and sweets dissolve faster, releasing in large quantities at the beginning of extraction, while caffeine belongs to large molecular substances. Although it starts dissolving at the beginning of extraction, its dissolution rate is extremely slow. Therefore, the caffeine in coffee beans cannot be completely extracted, nor will it dissolve excessively.

Practical Application of the Formula

To be generous, we can only calculate with half of the caffeine content. So the formula becomes: coffee bean gram weight × caffeine content of coffee variety (average) ÷ 2. Taking pour-over coffee as an example, a single serving of pour-over coffee uses 15g of beans, so our formula is 15 (coffee bean gram weight) × 1.3% (average caffeine content of Arabica) ÷ 2 (assuming only half is extracted), resulting in approximately 97.5mg of caffeine in this cup of coffee. By extension, if using 20g of coffee grounds, the caffeine calculation formula would be 20 × 1.3% ÷ 2, approximately 130mg. (Extraction time affects the amount of caffeine dissolved. When extraction time is too long, we can appropriately increase the extracted caffeine content.)

Espresso and Other Coffee Beverages

The same principle applies to espresso coffee. Because we can only get an approximation, the calculation method is identical. At the same time, since all espresso-based beverages typically use one shot of espresso, whether it's an Americano or a latte with lots of milk, their caffeine content is essentially the same. With this knowledge, everyone can now calculate how to enjoy coffee within the 400mg limit!

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473