One of the most commonly asked question we receive is: "is it true that espresso has more caffeine than regular coffee?"
Ask almost anyone and they will invariably say that espresso has more caffeine than regular coffee. The assumption makes perfect sense, what else would explain that caffeine buzz we get when we down a shot of espresso in the morning?
Interesting, but is this correct? Well that depends on your perspective.
During the 1950's a typical serving size of coffee ranged from 4 to 6 oz. But over the years our "cup" size has grown six-fold from approximately 6oz to 24oz - depending on the establishment.
According to the National Coffee Association (NCA) a typical cup of drip coffee (8oz) contains approximately 65-120 mg of caffeine. Not exactly a tight tolerance, but why is there such a large variation in caffeine content?
Well without getting overly technical, there are several factors including brew time, dwell time, water temperature, grind level, roast level, bean type, blend, etc. that all have a significant affect on the final extraction of caffeine. We will discuss those a bit later.
Now if we look at the level of caffeine contained in a typical cup of drip and espresso those figures come in at about 92.5mg and 40.0mg, respectively. Remember these are averages so the exact amount will vary.
As you can clearly see drip coffee with approximately 92.5mg contains a larger concentrationsof caffeine than espresso - how much more? On average about 2.3x more!
So there we said it - drip coffee has MORE caffeine than espresso! Case closed, go home!
Well, not exactly!!
If we take this approach its actually an unfair comparison and we need to compare "apples to apples".
A more correct approach would be to compare two beverages in terms of their caffeine concentration per ounce (oz).
In the case of drip coffee, we need to divide the 65-120 mg of caffeine by its serving size. In this case the caffeine is distributed over 8 oz resulting in: 8.125 - 15 mg per oz.
That means that for every ounce of coffee solution we can expect 8.125-15 mg of caffeine. For our purposes lets say 8-15mg
Whereas in espresso, even though we start off with about a 1/2 to 1/3 less caffeine (ie. 30-50mg) - all this caffeine is contained in just 1 oz of liquid or expressed numerically as 30 - 50 mg per oz.
Meaning that in just 1 oz of espresso solution we can expect 30-50mg of caffeine.
So what does all this mean?
Although we can conclude that drip coffee contains much more caffeine than espresso - this is all due to its much larger serving size - that is 8oz vs 1oz.
Obviously since espresso is served in much smaller volumes, we see less caffeine (from a beverage perspective).
But when viewed from a volume perspective - espresso has a much more caffeine than drip coffee.
The Bottom Line
So does espresso really have more espresso than drip? Well the answer really depends on your perspective. If we look at this issue:
- from a beverage perspective - drip coffee has more caffeine.
- from a volume perspective - espresso has more.
Comparison of Caffeine Content in Drip Coffee vs Espresso*
| 65-120mg / 8 fl oz (BP)
(8-15mg /1 fl oz) (VP)
30-50mg /1 fl oz (BP)
* numbers in bold (top) are from a 'beverage perspective' (BP); numbers in parenthesis are from a 'volume perspective' (VP).
So why do most people believe espresso has more caffeine than regular?
Well, part of the reason this belief has continued to exist is because caffeine itself an intensely bitter compound. Since espresso is roasted at a much darker roast which creates a higher concentration of 'bitter' molecules - the logical "connection" would seem correct - but it is in fact incorrect.
The bitter compounds that arise from darker roasts is not due to more caffeine, but rather bitter compounds created during the Maillard reaction.
It is this much lower concentration of caffeine (per serving) in espresso that allow Italians to drink upwards of 10 to 12 espresso's per day without getting overly jittery. Try drinking a dozen 12 oz cups of drip coffee and you'll likely end up with a visit to the hospital from excessively high levels of caffeine in your system.
Unfortunately its very difficult to "standardize" the caffeine of coffee beverages since there are numerous variables need to be considered, including:
- Beverage Size - are we comparing a cup at 4oz, 5 oz, 12oz or 24oz?
- Blends - many roaster create their own blends of various beans each with subtle difference in caffeine content.
- Bean Type - is the blend 100% arabica, robusta or both?
- Grind - was the coffee prepared with a fine grind, ultra fine grind, coarse, etc?
- Water Temp - was the coffee prepared with the recommended 195-205F temperature range?
- Milk - was milk added or now - as this will dilute the caffeine content per ml.
- Others - machine type, dwell time, etc.
All these factors make the calculation of caffeine in coffee beverages a real challenge. Hopefully with the implementation of industry standards by trade organizations we can begin the journey towards creating more standardized cups of coffee in our industry.