After I open a bag of beans, the flavour of the coffee seems better after the bag has been opened a day or more.

Does the flavour of coffee beans improve for a period of time after the bag has been opened? Perhaps I'm imagining it!


2 Answers 2


That is almost the opposite of my experience, after opening a bag of beans, they have noticeable less flavour after a couple of days. Coffee beans are more resistant than ground coffee though, as that decays in a couple of hours. Obviously, if beans are exposed to air for long enough, their quality is decreasing.

However there is an effect that improve them at first, simply because some of the processes from the roasting takes time to finish, and may require several days in order to do so. They may even require exposure to air (oxygen) in order to oxidise some of the compounds causing the flavour. Keep in mind that even though some of the compounds improve, other does not. The most notable degradation in the first days is caused by the most volatile aroma compounds evaporating.

This graph shows the stalling of coffee as a function of time. Note that this is just a visualisation of the aroma compounds evaporating, not necessary a measure of quality. The remaining compounds are also changing, and some of them improves over time.

staling of coffee

  • I think the rate at which coffee goes stale is quite a bit higher than your graph shows. For any ground coffee, staling happens within minutes. This is also true for vacuum sealed ground coffee. My own fresh roasted coffee is essentially stale after 14 days at room temperature. I generally freeze the roasted coffee beans at peak flavor, which is 3-4 days after roasting.
    – Rick G
    Feb 3, 2016 at 18:50
  • Most roasters I know recommend to wait some time before brewing, and it depends on the roast and type of beans. It can range from a couple days to a week with the beans I deal with. This is also in line with @Induction 's answer. You briefly mention this also in "some effects that improve them at first". The graph seems quite misleading, then. Any idea to improve on that? Feb 7, 2016 at 0:38
  • 1
    @EricPlaton Is this an improvement? I expanded the part about reactions, and added a note about the graph. Feb 7, 2016 at 0:54
  • Thanks, that's a great answer and, even though the graph may not be to actual scale, it does give me an idea of the flavour decay relative to the method of storage. Feb 7, 2016 at 11:13

Yes - you are totally not imaging it. Well, not really anyway.

Mostly the flavor of coffee will either improve or stay the same within the first couple weeks of it's roast date. Coffee should generally degas a bit before brewing & drinking (which it will degas with the bag open or closed). But by opening the bag you will indeed increase the degassing rate, which will change the flavor of the coffee when brewing. Which is a great thing until it starts to get old. I wouldn't take the graph in the other post to heart - it's really not to scale. Most light roasted coffees, and especially africans, may often taste at their peak around 10 days off roast. It's even more present when using them for espresso.

  • For medium roasts, we here get better results 3 days after roast. I agree @Hohmannfan graph should be just an example, not a complete reference. Feb 7, 2016 at 0:32
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    3 days sounds about right. I'd say the darker the coffee is - the quicker it needs to be used.
    – Induction
    Feb 8, 2016 at 3:44

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