In our office we have a bean-to-cup machine. The rate at which we use it means we always have fresh beans - generally it tastes pretty good for machine-made coffee. However, first thing in the morning, just after turning it on, the first few coffees can taste very acidic indeed. Is there any potential remedy for this other than throwing away the first few coffees?

1 Answer 1


My thought is that once you turn on the machine, the machine starts to heat the water. Often the heating system is regulated by a PID regulation (Maybe on-off regulation). The machine will heat the water fast to make sure you can get your cup of coffee:) Once the water is heated it will stabilize to the intended temperature. If the water is heated above the intended temperature it will cause acidic compounds to be extracted from the beans. After a while the temperature is stabilized and you will experience that the coffee is no longer acidic.

Another theory is that the pipes within the machine are not clean.

You can test both.

Try turning on the machine an hour before making the first cup. If this helps it is probably a temperature issue.

If not try to clean the machine by running through hot water before making the first cup.

Hope one of these solutions will help you with your issue.

"Life is too short for bad coffee"

  • Right, but doesn't one always have to run through some hot water? -- and many (most? all?) machines of that type do it automatically. Oct 26, 2015 at 13:10
  • I'm not an expert on the different types on the market but the one we have at work requires manual cleaning. But you are right - an automatic cleaning program should be implemented in all coffee machines. Nevertheless fouling of the pipes could be the reason why the coffee tastes acidic.
    – Krumme
    Oct 26, 2015 at 13:42
  • @IvanKapitonov Ours does, but only a little spurtlet before each drink (I keep my cup away while it does this, others seem not to care)
    – fredley
    Oct 26, 2015 at 15:57
  • @Krumme It does have a manual cleaning cycle, automatic would be awful. Imagine trying to make a coffee and triggering the 20 minute cleaning cycle! Ah!
    – fredley
    Oct 26, 2015 at 15:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.