A google search brings up a great article by Hannah from Fellow Products called "Understanding Degassing: Is Fresh Best?," in which she claims:

Degassing varies depending on the type of coffee and roast. It therefore can take anywhere from 2 to 12 days until the coffee is ready to brew. Some rules of thumb:

The first 24 hours is when a bulk (approximately 40%) of CO2 leaves the bean.

Darker roasts usually degas faster than lighter roasts

Longer roasts usually degas faster than faster roasts.

Is anyone aware of any other research on this topic? Can anyone corroborate, or does anyone disagree?

  • 1
    I regularly roast a natural processed Ethiopian Yirgacheffe and find it takes more like a week before is has sufficiently degassed to be able to brew without foaming excessively. And I put it under a slight vacuum right after roasting to try and speed it up a bit.
    – PJNoes
    Commented Jan 19, 2017 at 0:38
  • How do you put it under a vacuum? And how do you store it after that? Any thoughts on valves? Thank you! Commented Jan 19, 2017 at 14:32
  • I use a Vacu-Vin wine vacuum pump. I just take an empty (clean) wine bottle and fill it with freshly roasted beans, then pump out as much air as I can with the Vacu-Vin. I repeat for a day or two and it's really surprising how much gas accumulates in the bottle for the first couple of days. After day 3 or 4 it's obvious that no more C02 is coming off the beans so I just use that as my storage system too.
    – PJNoes
    Commented Jan 23, 2017 at 17:16
  • I don't know how to link to a previous question but look up question #2881 and I posted a picture.
    – PJNoes
    Commented Jan 23, 2017 at 17:20

3 Answers 3


Degassing is discussed a few times. The most cited answer in Coffee SE is probably this question.

In short:

  • Degassing takes up to 2 to 4 days to achieve drinkable coffee. If you really want to shorten this, grind earlier. But you should try yourself for best timing.
  • The best flavor is around 1 to 2 weeks. Again, you should follow your taste buds based on the beans and the roast degree.

Another major component when talking about degassing is whether or not the coffee is ground or not...


  • Bob, I was under the impression that it's best to grind the coffee only just before brewing. Is there another camp of thought on this? Commented Jan 15, 2017 at 18:14
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    Generally it is best to grind right before brewing. However that is not practical all the time. Once ground coffee is considered stale within a half an hour. Commented Jan 15, 2017 at 18:20

Degassing - what a lovely topic.

May i offer an experience is that, regardless of roast: of course one can grind anytime,

  • central american coffees seem generally to take about a week to be truly flavourful after roasing - whether this is all down to degassing per se or just being in the air for that time as well, dunno - just experience.

  • african coffees can be ready in 36 - 48 hours -

as for STALE-ness half hour after grinding?

well - have you tried it?

I've been surprised and delighted when having to travel with ground coffee - that it can be absolutely fantastic.

there's an aeropress method that was a world champion win in 2016 perhaps? that deliberately used "ground the night before" beans.

personally i love the privilege of grinding right before brewing, but i am surprised at how good/different ground coffee can be over the course of a week's road trip travelling with a plastic V60 01, some filters and a heating coil when not likely to have a kettle close by (sadly common in US hotels).


  • this is very interesting. thanks. Where did you get this info that degassing varies based on origin? What about Indonesian/Moka Java, et.al. ??
    – JDOaktown
    Commented Sep 9, 2022 at 21:24

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