THE PROCESS IN MOTION

How much caffeine is in a cup?

Start the scene or choose a stage. The animation simplifies the mechanism; what follows gives the details and the available references.

▶ Play the process01Almost all the caffeine goes into the water02The species matters03Espresso or filter: concentrated is not loaded04The dose makes the difference05Light or dark: almost the same

Almost all the caffeine goes into the water

Caffeine is very soluble in hot water: it is extracted almost entirely in all methods. It is therefore the quantity of coffee used that decides, not the strength of the taste; a bold taste has nothing to do with caffeine, which contributes only a discreet bitterness.

Read the stages without animation

1. Almost all the caffeine goes into the waterCaffeine is very soluble in hot water: it is extracted almost entirely in all methods. It is therefore the quantity of coffee used that decides, not the strength of the taste; a bold taste has nothing to do with caffeine, which contributes only a discreet bitterness.
2. The species mattersThe content depends first on the species: a canephora contains up to twice as much caffeine as an arabica. The training document sums it up: for little caffeine, a washed arabica as espresso, with a glass of water alongside rather than a long coffee.
3. Espresso or filter: concentrated is not loadedAccording to EFSA, a 60 mL espresso contains about 80 mg of caffeine and a 200 mL filter coffee about 90 mg: the first is more concentrated, the second contains slightly more. A 220 mL tea supplies 50 mg, a 355 mL cola 40 mg.
4. The dose makes the differenceA large filter coffee made with 20 g of grounds exceeds 150 mg, and a double espresso of 18 g approaches 130. The cup is not a unit: two coffees served under the same name in two establishments on the same street can differ by a factor of two or three.
5. Light or dark: almost the sameUkers wrote in 1922 that part of the caffeine sublimes during roasting, that is, passes directly into the vapor state, and that an Italian roast pushed to carbonization retains almost none. Modern analyses temper this: the molecule is stable at usual roasting temperatures, and the gap between light and dark comes mostly from the loss of mass of the bean. Measured by weight, a dark roast is neither much more nor much less caffeinated; this point remains a gray area, no reference measurement having been verified here.

To remember: To know what a cup contains, ask how much coffee went into it, and of what species, not whether it is bold.

Read the full article and its sources ↓

All the values above are in milligrams, and all general-audience articles convert them into cups. The cup is not a unit. The content depends on the species (a canephora contains up to twice as much as an arabica), the dose of grounds, the volume of water, the fineness, the temperature, the contact time. Because caffeine is very soluble in hot water, it is extracted almost entirely in all methods: it is therefore the quantity of coffee used that decides, not the strength of the taste.

According to EFSA, a 60 mL espresso contains about 80 mg, a 200 mL filter coffee about 90 mg, a 220 mL tea 50 mg, a 250 mL energy drink 80 mg, a 355 mL cola 40 mg, 50 g of dark chocolate 25 mg. But a large filter coffee made with 20 g of grounds exceeds 150 mg, and a double espresso of 18 g approaches 130; two coffees served under the same name in two establishments on the same street can differ by a factor of two or three.

The caffeine in a serving

Approximate content per serving, compared with the threshold of two hundred milligrams per intake set by EFSA for an adult.

Two espressos stay under the threshold per intake; it is the cumulative total of the day, four hundred milligrams, that bounds consumption.

The figures

	Caffeine per serving
Filter coffee, 200 mL	≈ 90 mg
Espresso, 60 mL	≈ 80 mg
Energy drink, 250 mL	≈ 80 mg
Tea, 220 mL	≈ 50 mg
Cola, 355 mL	≈ 40 mg
Dark chocolate, 50 g	≈ 25 mg
Decaf, 470 mL	3-32 mg

EFSA 2015 via EUFIC; Wikipedia, Decaffeination (Florida study, 2006); ANSES 2014; MDPI 2020, pp. 11, 93

The training document sums it up: for little caffeine, a washed arabica as espresso, with a glass of water alongside rather than a long coffee; and a bold taste has nothing to do with caffeine, which contributes only a discreet bitterness.

EFSA 2015, table of content per serving, via EUFIC, EFSA opinion on the safety of caffeine, 05/27/2015; professional training document, Caffeine and decaffeination processes, p. 2; LC ch. 19

Ukers wrote in 1922, with table III in support, that part of the caffeine sublimes during roasting, that the proportion decreases with color and that an Italian roast pushed to carbonization retains almost none. Modern analyses temper this: the molecule is thermally stable at usual roasting temperatures, and the gap between light and dark comes mostly from the roast loss of the bean, which concentrates caffeine per gram of roasted coffee while diluting it per bean.

The consequence for the cup is small: measured by weight, a dark roast is neither much more nor much less caffeinated than a light one. This point appears among the gray areas, because no reference measurement has been verified here.

Ukers 1922, ch. XVIII, table III; state of modern knowledge not verified against a primary source, see gray areas