For some years I could not drink coffee because it caused me instant digestive problems. I tried various kinds of preparation and beans but often it only took some minutes until the bodily reactions started.

Then someone suggested to use the aeropress and now I can drink coffee again.

Can someone tell me a reason?

What I tried earlier: caffeine free coffee, espresso, old style filtered coffee, old style filters with adding cooking water by hand, modern automated coffee makers. Freshly ground, non freshly ground, mokka, adding powdered directly into the cup and surely some others I don't remember.

Now with the aeropress I used different kinds of beans and different mills, different filters (metal and paper) and never had any problems.

How I use the aeropress: I add two spoons of coffee, put a little hot water on it. After a couple of seconds I fill up to full, wait until some water is through, then gently squeeze.

I don't have any problems with caffeine.

1 Answer 1


The digestive problems you've experienced may be due to the acidity of the coffee. Now lighter roasted coffee will definitely be more acidic so the roast level of the bean can be at play. Not only that, but underextraction can cause high levels of acidity also.

The only discernible difference I can garner from what you've told me is that in the Aeropress there is a slight form of full immersion brewing. This will better encourage all parts of the coffee to be well extracted and so reduce the acidity of the resulting cup.

If you're curious as to what the real cause is, buy two different batches of beans, one medium-dark roast and one light roast. Then perform Aeropress, French press, pourover, espresso and possibly drip extractions with both beans and note down your gastric reaction to each cup. If there is almost no significant difference between any of them to how it makes you feel i.e. it seems to occur at random, you might just be hyper-sensitive to small changes in acidity caused by the differences in the imperfections of each extraction.

Good luck.

  • I think you might be confusing acidity as in a flavor of coffee and acidity as a chemical attribute. In a bitter over extracted coffee you will have extracted these acids as well. In any case, the pH value of almost all coffee extraction methods is in the same range between around pH 5,5 and pH 6. However the aeropress is advertised as producing coffee with only a fraction of the acidity of a drip or french press. Might have to do with the lower brewing temperature. I couldn't find any specific pH levels though, I might measure it myself over the weekend and report back here.
    – avocado1
    Commented Nov 4, 2016 at 15:30
  • You're right in a sense. Underextraction might not provide a huge difference in acidity, but it makes it more concentrated as it isn't diluted by more liquid in an overextracted cup. But I do think roast level contributes much more to acidity than the extraction does. It'll be interesting to see your results.
    – Shiri
    Commented Nov 4, 2016 at 16:02
  • Yes if you run way too much water through the coffee grounds at some point it will approach the ph level of water. However I was more thinking of immersion techniques where you don't add more water by the second or a fixed pour over recipe where over extraction would rather occur if your grind is too fine and the grounds steep too long in the water. In these cases the acidity will not be much different and the coffee in general would be more concentrated, as more solubles are dissolved in the water. If you think of espresso however you are right, a ristretto is probably slightly more acidic.
    – avocado1
    Commented Nov 4, 2016 at 16:11

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