The amount of caffeine in a cup of coffee can vary significantly due to several factors, from planting to brewing.
The amount of caffeine in a cup of coffee will depend on the variety of the coffee plant, the degree of roasting of the beans, the type of grinding, the brewing temperature and brewing time, and the amount of coffee and the type of water used.
In this post, we will explore these factors in detail and provide a guide to understanding how each can affect the amount of caffeine in your cup of coffee.
Caffeine in coffee
According to data published in Dietary Guidelines for Americans 2015-2020, more than 95 per cent of adults in the United States consume foods and beverages containing caffeine.
Caffeine is the most widely consumed psychoactive drug in the world, and one of the easiest ways to get it is by having a cup of coffee.
After consumption, it is quickly digested and absorbed into the bloodstream, stimulating the brain and central nervous system. This is why it is so effective for tasks that require concentration, such as driving or studying.
Caffeine is present in coffee, black and green tea, chocolate, and some soft drinks and energy drinks; in the latter two cases, of course, artificially added to the formula.
How much caffeine is in a cup of coffee?
The truth is that the caffeine content of coffee varies considerably from one cup to another, depending on many factors. However, an approximate value can be given for a standard cup of coffee:
An average cup of coffee contains about 95 mg of caffeine.
What factors does the caffeine in a cup of coffee depend on?
Factor 1. Method of preparation of the coffee
With each brewing method, the coffee’s contact with the water varies, allowing different amounts of caffeine to be extracted in the resulting cup.
Therefore, the amount of caffeine in coffee will differ whether it is an espresso, a filtered coffee or a cold brew.
The cold brew will have much more caffeine than the first two, as the water soaks the ground coffee for hours. While in espresso, the water circulates under pressure and for seconds, and in filtered coffee for minutes and without pressure.
Factor 2. Preparation time
Closely related to the above concept, each method of coffee extraction requires different brewing times.
The espresso and superautomatic ones are very convenient because they allow you to obtain an excellent coffee in just a few seconds. Moka pots and filter coffee machines make us wait a little longer than for espresso, while Cold Brew is the most time-consuming.
The longer the brewing time, the more caffeine the coffee will have.
The amount of caffeine here depends on how long the coffee has been in contact with the water. Cold brew infusions can take up to 24 hours, using more coffee as a starting point, and this increases the caffeine content of the resulting beverage, even if the result seems “smooth” to us.
Factor 3. Cup size
The same amount of ground coffee is not always used to prepare similar quantities. In principle, the more grams of coffee in the brew, the more caffeine the cup will contain. The standard for espresso coffee is 7 g of ground coffee per cup. However, more and more baristas are questioning this convention.
There is no such thing as a perfect espresso; it depends on many variables. Some make espresso with 7 g of and others with 10 g of coffee per cup. Other types of beverages use higher ratios, such as filter coffee.
Factor 4. The roasting process
Although dark roasted coffee beans may have a more bitter taste that you might think contributes to the caffeine, it means quite the opposite. The bitter notes provide this “stronger taste” that the coffee takes on as it roasts for a few minutes.
The more you roast coffee beans, the more caffeine is lost.
They contain less caffeine than light or medium roasts because they have not had time to lose the caffeine during the roasting process.
Factor 5. Type of grinding
The grind influences how the brew is prepared, which is why a finer or coarser bean is usually recommended depending on the type of brew.
Generally speaking, the longer the extraction process, the coarser the grind should be. Espressos are coffees with a fine grind, while the French press has a coarse grind.
As for the caffeine level, we should know that a finer grind provides a higher concentration of caffeine in the cup.
Factor 6. The species of the coffee plant
Whether the coffee is arabica, robusta, or a blend of these two species in different proportions determines, and very much so, the degree of caffeine your coffee has. We can safely say that a 100% Arabica will always have less caffeine than a 100% Robusta.
It is no secret that Arabica coffee has about half the caffeine of Robusta coffee.
Amount of caffeine according to the type of preparation
Now that we know how different factors influence the amount of caffeine in your cup, let’s see how many milligrams you can expect from the most popular types of coffee.
A cup of filtered coffee contains around 70-140 mg of caffeine, with 96 milligrams in an average 8 oz cup.
This wide range can be attributed to the specific brewing method you select to prepare your beverage. The V60, Chemex, Kalita, etc., have slightly different brewing specifications regarding grind and steeping time, determining the caffeine content.
On average, a standard single espresso will give you a caffeine dose of 63 mg and 120 mg for a double espresso.
Espresso coffee is prepared by passing small amounts of hot water through finely-ground coffee under high pressure.
The brewing process takes about 25 seconds and produces a small 30 ml portion of concentrated coffee. The same as an Americano.
Coffees such as Lattes, Cappuccinos, Cortados, and Flat Whites are prepared by blending a single or double espresso with varying amounts of steamed milk. While the milk dilutes the bitterness of the coffee and is responsible for a milder taste, it does not alter the caffeine content of the beverage.
Although a standard cappuccino may taste stronger than a latte of the same size, if both use a double dose of espresso, both contain around 120 mg of caffeine per cup.
The tricky part of keeping in mind is that if you buy a large latte at a coffee shop like Starbucks, they are likely to use 3 or 4 shots of espresso. So it will have four times more caffeine than coffee alone.
And although the coffee tastes smooth, you are consuming high amounts of caffeine, which can build up significantly over the day if you drink more than one of these coffees. If you drink three of these coffees, you could drink the caffeine equivalent of 9 – 12 single coffees.
Instant coffee is brewed coffee that has been freeze-dried. It has a weaker taste and contains less caffeine than regular coffee, at around 20-90 mg per cup.
A cup of Cold Brew contains around 150-230 mg of caffeine, which can be more than double the dose you get from filtered coffee. The higher caffeine content comes from the way this coffee is prepared.
Because cold water is used instead of hot water, the coffee must be in contact with the water for up to 24 hours. This gives the water time to dissolve more caffeine in the cup of coffee.
Does decaffeinated coffee not contain caffeine?
Decaffeinated is a great option to reduce your daily caffeine intake; a cup of decaf is not completely caffeine-free. How many mg of caffeine are in a cup of coffee labeled “decaffeinated”?
A cup of decaffeinated coffee contains approximately 1% of the caffeine that the same cup of coffee would contain, with an average of 3 mg, depending on the decaffeination process. And while this is not zero, it is much lower than a standard cup of coffee.
What happens when I drink too much caffeine?
Caffeine is a stimulant that can help boost your metabolism, improve cognitive function and enhance athletic performance. But if you consume too much caffeine, you may experience some negative effects, such as anxiety, heart palpitations, restlessness, or sleep disruption. It is, therefore, not advisable to over-consume.
According to the FDA, the general guidelines for the recommended daily caffeine intake are 400 mg of caffeine per day for a healthy adult, which means about 4-5 cups of coffee, depending on the type. Consumption of more than 400-600 mg of caffeine daily can have diverse and serious effects.
And how much caffeine can we consume daily without fearing health risks? EFSA gives the following figures:
- General healthy adult population: 200 mg of caffeine in a single dose. 400 mg of caffeine daily (about 5.7 mg/kg daily).
- Pregnant and breastfeeding women: up to 200 mg of caffeine consumed throughout the day.
- Children and adolescents: no more than 3 mg/kg.
The latest research suggests that people who are used to caffeine need around 400mg per dose to improve concentration and performance, while 200mg may be sufficient for those who are less caffeine dependent.
When monitoring your daily caffeine intake, don’t forget to consider other sources of caffeine in your diet besides coffee. Soft drinks, tea, energy drinks or even chocolate can significantly affect your daily caffeine intake.
Everyone’s sensitivity to caffeine in their body is different, and it is possible to develop some tolerance to caffeine. This is why some people can drink 4 cups of coffee daily without adverse effects. Others will feel the jitters after their second cup, even after the first.
Caffeine does not affect all people equally, as it depends on many factors such as age, physical constitution, illness, taking medication or certain genetic components. The stimulant effects begin to be felt 15 to 30 minutes after ingestion, and the body usually takes about four hours to eliminate it, with a range of two to eight hours in some cases.
Conclusion on caffeine in coffee
Coffee can be prepared and enjoyed in many different ways. It is important to know what we are drinking and be more aware of the amount of caffeine we ingest daily to adapt our consumption habits.
The amount of caffeine in a cup of coffee depends on several factors, including the brewing method, type of coffee, roast, grind and cup size. And all these factors mean that you can double or even triple the caffeine intake in a cup of coffee.
And if you’re a hardcore coffee drinker and don’t want to overdose, you can always rely on decaffeinated coffee, which can also be very tasty.
You may be interested in Café Manchado: what it is and how it is made.