Caffeine in Coffee Depends on a Number of Factors
Have you ever wondered precisely how much caffeine is in that cup of coffee or espresso you are drinking?
The answer is that a typical shot of espresso contains about 40-50 milligrams of caffeine, while a typical cup of coffee has about 100-120 milligrams of caffeine. But these are not 100% correct answers.
A normal brewed coffee will contain on average, 11.8 mg caffeine per fluid ounce of brewed coffee, according to the USDA.
Note that most coffee machine manufacturers define their "cups" as 5-oz cups. For example, a 12-cup coffee machine will be brew 60 fluid ounces of coffee. You can then multiply 60 fluid ounces by 11.8 mg to get 708 mg of caffeine per pot of coffee for that specific machine. You may be interested in our how much coffee per cup article for more details.
A fluid ounce is 30 ml of fluid, as opposed to an ounce of weight, which is 28 grams.
Of course the exact amount of caffeine depends upon various things like what type of coffee beans you are using (Robusta beans have significantly more caffeine than Arabica beans), what coffee coffee brewing method you are using, how long the coffee beans were roasted (roasted diminishes the caffeine content), the extraction time and water temperature, and other factors.
Caffeine Content by Single Origin
Single Origin: Percentage (by weight)
- Brazil Bourbons: 1.20%
- Celebes Kalossi: 1.22%
- Colombia Excelso: 1.37%
- Colombia Supremo: 1.37%
- Ethiopian Harrar-Moka: 1.13%
- Guatemala Antigua: 1.32%
- Indian Mysore: 1.37%
- Jamaican Blue Mtn/Wallensford Estate: 1.24%
- Java Estate Kuyumas: 1.20%
- Kenya AA: 1.36%
- Kona Extra Prime: 1.32%
- Mexico Pluma Altura: 1.17%
- Mocha Mattari (Yemen): 1.01%
- New Guinea: 1.30%
- Panama Organic: 1.34%
- Sumatra Mandheling-Lintong: 1.30%
- Tanzania Peaberry: 1.42%
- Zimbabwe: 1.10%
- DECAFS: all @ .02% with Swiss Water Process
(Source: Newsletter--Mountanos Bros. Coffee Co., San Francisco)
eg. if you use 10 grams (10,000 mg) of coffee (generally, 2 tbsp), with 1.20% caffeine by weight, you'll get roughly (10,000 mg * 0.012 =) 120 mg of caffeine.
Note: caffeine is not necessarily 100% extracted via all brewing methods. For example, roughly twice as much caffeine is extracted by espresso brewing methods (high pressure, high temperature) than by standard drip-brewing. This means you won't get 120mg of caffeine per 5.3 ounce (160 ml) brewed coffee.
These numbers may be correct for the coffee offered by Mountanos Bros. Coffee Co., but they probably are not neccessarily correct in a generic way. Caffeine will vary from farm to farm, and plant variety to plant variety, and even year to year.
Should you choose a coffee based on caffeine content? Absolutely not. Coffee should be chosen based on flavor. If you need more caffeine, just drink another cup 🙂
Caffeine by Coffee Brand
Note that serving sizes vary by brand, which makes a direct comparison slightly more difficult.
Caffeine by Tea Brand
Does a Medium Roast have more caffeine than a Dark Roast?
Since coffee roasting only marginally decreases the amount of caffeine, a light roast, medium and dark roast will have negligible differences in caffeine content. There are myths that go both ways, with people claiming light roasts have more caffeine (negligibly true), and others claiming dark roasts have more caffeine (likely due to a more developed "coffee" flavor), but good old science comes to the rescue here:
Caffeine did not undergo significant degradation with only 5.4% being lost under severe roasting.
This is further offset by the fact that green coffee loses anywhere from 10%-20% of it's weight during the roasting process (evaporation of water) - meaning darker roasts may or may not have slightly more caffeine when comparing exact weights after roasting.
In general, however, it is true that a cup of regular Drip-Brewed, Arabica coffee with a medium roast will have about 120 milligrams of caffeine, and that a 30 ml shot of espresso with an espresso roast and Arabica coffee beans will have about 120 milligrams of caffeine.
Does Robusta have more caffeine than Arabica coffee?
As a general rule of thumb, robusta has approximately twice as much caffeine as arabica.
This will vary depending on specifically which arabica beans you're comparing against specifically which robusta beans.
The only way to know this, is by submitting samples to a lab for chemical analysis.
How Much Caffeine in a Cup of Coffee
It was 1819 when German chemist named Friedlieb Runge isolated caffeine though the first coffee shops had been opened in 1530 in Istanbul, Damascus and Syria.
In nature caffeine serves as a natural pesticide helping plants defend against predators including harmful insects.
When caffeine is consumed it leads to more alertness and energy through its ability to mimic a compound called adenosine that binds to the adenosine receptors of the brain. When this happens it has the effect of blocking real adenosine from its job of creating a feeling of drowsiness and slowing nerve impulses.
- A regular 43-gram Hershey's Milk Chocolate bar contains about 10 milligrams of caffeine.
- A typical cup of Decaffeinated Coffee containing about 7 ounces will likely have about 10 milligrams of caffeine.
- A 6 ounce cup of black tea will likely have about 50 milligrams of caffeine and green tea only about 30.
- You will get about 34 milligrams of caffeine in a 12 ounce Coke.
Caffeine can be chemically synthesized though this is not commonly done since caffeine is so easy to get as a by-product of decaffeinating substances with caffeine, such as coffee beans.
If you are wondering how much caffeine is in a cup of coffee because you are worried about your overall caffeine consumption then realize that there are many factors involved, and also remember that Instant Coffee is typically made using Robusta coffee beans which have about twice as much caffeine as Arabica coffee beans.
Caffeine Impact on Health
In general moderate amounts of coffee have only a mild effect on the body and do not cause the problems associated with excess caffeine intake.
Caffeine is actually negatively correlated with all-cause-morality: https://www.ncbi.nlm.nih.gov/pubmed/28697850
This means that coffee drinkers have a lower chance of dying in a given year, than non-coffee drinkers. The exact mechanism is unknown (anti-oxidants, life-style factors, or being more alert), but the general consensus is that drinking coffee is healthy.
If you are trying to quit drinking coffee and worried about caffeine withdrawal symptoms due to the caffeine in coffee that your body has become so accustomed to, then just reduce your amount of intake a little each day and you will barely notice any craving effects that may be associated with stopping caffeine intake.
You can also try drinking Decaffeinated Coffee since much of the pleasure of enjoying a cup of coffee in the morning is preserved and you may not even miss the caffeine at all since the warm beverage itself does a lot to help wake you in the morning.
With the French Press brewing method using strong coffee beans one cup of coffee can have way more caffeine in it that a moderately brewed cup, so you may just try using fewer grinds when you brew your coffee. If you like to visit Starbucks and enjoy espresso drinks then perhaps just ask for one shot of espresso instead of two.
The body's liver metabolizes caffeine after it is consumed and the stomach and small intestine absorb it, usually in less than one hour, and it proceeds to spread throughout the tissues of the body.
Caffeine in Single Origin Coffee Beans
To make a real difference in the caffeine content of a blend, you'll need to add Robusta beans rather than playing with varieties of Arabica. The blend shouldn't be dictated by how much caffeine you can squeeze out of it however - taste will always trump
Some Caffeine Stats
The chemical formula of caffeine is C8H10N4O2 and the chemical name of caffeine is 1,3,7-trimethylxanthine, and it is found in about 60 different plants.
About 450,000 cups of coffee are consumed in the U.S. every day.
Most humans consume their caffeine by getting it from either coffee beans or tea leaves, or else from various beverages that contain extracted caffeine, or from various natural sources like cocoa beans, the kola nut, Yaupon Holly, yerba mate and guarana berries.
Every day around 90% of adults in the U.S. consume caffeine.
Caffeine in Folgers Black Silk
Folgers Black Silk has roughly the same caffeine content as regular folgers coffee. As noted above, coffee only loses roughly 5% of its caffeine content between a light roast and a dark roast. While Folgers Black Silk is a very dark roasted, strong-tasting coffee, it will not have significantly less caffeine.
Folgers coffees contain 30-40mg caffeine per 1 tbsp of ground coffee, which is 60-80mg caffeine per 12-oz brewed coffee.