How does the amount of water I pour into an Aeroporess impact the caffeine content of my cup of coffee?

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If I make two cups, for cup A I use just enough water so that the 1 is covered on the Aeropress, and for cup B I use enough water so that the whole tube is filled, then what will be the ratio of caffeine in the two cups? Of course, I assume that the same amount of coffee is used for both cups.

2 Answers 2


Of course, I assume that the same amount of coffee is used for both cups.

In that case:


Caffeine dissolves very readily in water. The caffeine content in your cup is mainly and almost solely determined by the amount of coffee you use. The impact of any other factors such as amount of water, water temperature, and pressure are negligible.

To get a rough estimate of the amount of caffeine in your cup do this: multiply the amount of coffee in grams by 10, that's roughly the amount of caffeine in milligrams.


I would say yes. If you would increase the grounds : water then more caffeine would dissolve in the water. Caffeine is an extremely soluble compound; however, more caffeine does not mean a "better" test. It could become unpleasantly bitter. Cup A will have more caffeine than B. let's say you use 1/2 the water in Cup A compared to Cup B, theoretically Cup B will have close to double the caffeine saturation than A; however, the sum total caffeine will remain the same, . This is given all other factors are constant such as the temp, rate of extraction etc. I could go on and on. Shivers in Chemistry Labs.

A simplistic way of thinking of this is:

Let's say you were making a instant cuppa (not to scale. Please don't use this ratio). Moreover, you can also decrease the water what matters here is the ratio.

cup w/ 1 tbsp coffee --> slightly weak in Taste and caffeine

cup w/ 2 tbsp coffee --> Perfect in Taste and More Caffeine

cup w/ 3 tbsp coffee --> Bitter as Hell and **Too much caffeine*

if you like it at this level then seek help and have your cardiologist on speed dial

  • Hey @Dhruv, and welcome. Thanks for the answer. I should perhaps point out that I'm not increasing the amount of coffee in the above thought experiment.
    – gen
    Commented Apr 16, 2020 at 19:13
  • Yeah. My answer was not exactly clear. It's all about the ratio Commented Apr 16, 2020 at 19:17
  • I was editing it. Hopefully it makes more sense Commented Apr 16, 2020 at 19:18

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