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For a given type of bean, do different brewing processes and temperatures (drip, French press, Mocha, espresso, cold brew, etc.) produce coffee with different caffeine content?

It would seem temperature isn't a factor because, according to this answer, "caffeine is chemically stable even when passed through its boiling point (evaporation temperature) of 312°C (593.6°F)".

The brewing method, however, would seem to matter. Mocha, espresso machines would seem to extract the most caffeine because they require finer grounds and use higher temperatures (steam) and pressure.

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Short answer: No

Slightly longer answer: The temperature, pressure and method of brewing barely impact the amount of caffeine extracted from the bean.

Because caffeine dissolves so readily in hot water, the single most important factor in determining the amount of caffeine in the cup is the amount of coffee used to prepare said cup. Arabica beans contain about 0.8-1.4% of caffeine by weight, depending on the variety. So if you were to brew an espresso (15g in 30g out) or a pour over (15g in 250g out), you would have the same amount of caffeine in each beverage.

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Espresso does indeed extract more caffeine than other brewing methods except possibly Turkish (which I'm not familiar with). There are a few reasons why.

Grind size is one: espresso's very fine grind size results in greater surface area of the beans compared to the grind sizes used for most other brewing methods.

Two is pressure. The pressure with which water is pushed through the coffee grinds agitates the grinds. As you probably have seen from stirring sugar or other solutes into water, agitating the solvent and/or the solute allows exposure of lower parts of the solvent to higher concentrations of the solute, resulting in faster / more complete dissolving.

Third is that concentration, which is related to the other two factors. Espresso uses a small amount of water to brew compared to drip, pour over, or French press. A double shot uses between 2 and 3 ounces of water to brew (some gets left behind in the portafilter), and the drink volume produces by this brew method (in the US) is only ~2 ounces. Caffeine per milliliter of espresso is nearly double that of the next highest contender (which is cold brew--which cold brew achieves by using a very long brew time).

That said, many coffee drinkers dilute their coffee with various additives. Diluting of course will change the consideration of caffeine concentration (but not caffeine content).

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  • I'm not sure if the volumetric comparison is fair. I might drink a 30mL espresso but I would drink at least 120mL of French press coffee in one serving. Another approach might be to compare caffeine extracted from the same amount of beans, but then I guess you would use more beans for a single serving of French press compared to a (double) shot of espresso. – JJJ♦ May 7 at 21:01
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    Yep. Also the question is about the effect of brewing method on caffeine extraction. No matter the total volume of the drink when fully prepared, brew volume varies quite a lot by method. Caffeine per mL of brew is a nice, normalized metric. If you add 8 ounces of milk to your espresso and want to compare that to other brew methods' equivalents of "10 ounces with milk", you end up with an absurdly complex comparison since the quantity of diluting liquids will vary by specific brew profile. – R Mac May 7 at 23:09
  • Should time not also be factored into the considerations? After all an espresso is prepared in a few seconds, while cooking a Turkish coffee in a cesve takes around ten minutes. – Martin Peters May 9 at 8:54

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