Which lasts longer: ground or unground coffee? And why?

It would seem unground lasts longer because less of it is exposed to air. Is this true?

2 Answers 2


That's correct. The greater surface area of ground coffee allows more trapped carbon dioxide to be released, taking aroma compounds with it, as well as making way for oxygen in the surrounding air to oxidize the aroma compounds and coffee oils.

  • Cue: heated discussion on whether or not to put it in the fridge/freezer, or leave it in the cupboard ;-))
    – Tetsujin
    Commented Dec 10, 2019 at 16:28
  • If long term storage is the goal, I guess the way to go is green coffee beans and a home roaster. Commented Dec 10, 2019 at 20:40

It's not even if it lasts longer - beans will still be better at 2 weeks old than a supermarket bag of ready-ground is at first opening.

There are very good reasons a 'proper' coffee shop will grind the beans immediately before making your coffee. If there was nothing to be lost by bulk grinding it & grabbing a spoonful at the time of order… that's what they would do. It would be far more efficient.

There are some volatile oils which are first to go, very soon after being ground. Some of them are already gone even before they can bag it for sale; another half are gone before you buy it & open the bag.

Even as much as 4 weeks later, beans still won't have haven't lost them all - though they'll not be as good as when you first opened it, it won't be 'flat' yet.

I get through a lot of coffee, maybe 500g a week. I buy it in kilo bags & they're just as good two weeks after opening. A bag of supermarket ground you'd be able to smell the 'flatness' at 2 weeks.
I don't know another word to describe it, it's not stale but it's nowhere near as vibrant as it should be.

I'm talking of 'vac-packed' foil with a 'breather' valve at all times, above. If you buy truly fresh-roast I don't know the curve, as I get it so rarely.

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