I am getting conflicting information online about whether or not coffee needs to be stored in an air-tight container. There seem to be two camps:

  • Container must be air-tight
  • Container must have CO2 vent

Even coffee canister manufacturers seem to be at odds with one another. Take the following two products for example, both of which I own. The first is air-tight with a strong vacuum seal whereas the second has an opening in the lid that takes the same type of CO2 filter you see in commercial coffee bags (in fact, I will tear them out of the bags and use them with this canister as they're usually the same type as the ones that initially ship along with it).

So what is the final answer as to the proper way to store coffee, specifically whole beans in this case? What are the implications of CO2 build-up in the canister if you open the canister several times per day? Is the CO2 filter on a home coffee canister just a gimmick that only serves a purpose on coffee bags that sit on a shelf sealed for days or weeks on end?

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2 Answers 2


How to store coffee beans is a much opiniated area. Degassing CO2 from coffee beans is most important right after the coffee has been roasted, since it would release a lot there and then gradually release less and less over days and weeks. If then beans can't release the CO2, then there will be a buildup and since CO2 tastes sour, then it will affect the coffees taste.

Coffee should in general not be stored for too long after it's been roasted, since that will also negatively affect the taste. Storing it dark, dry and airtight will potentially keep it fresh a bit longer, but the best is in my opinion 1 week after roast and before 4 weeks after roast.

  • Please try to add references to support your answer.
    – JJJ
    Dec 15, 2019 at 23:39
  • 1
    Isn't one of the reasons that coffee containers should be airtight the simple fact that roasted, ground coffee is highly hygroscopic(i.e. keen at absorbing moisture) and if left open to the air will become "lezaza" (it will become chewy instead of porous and crunchy) which will inturn impede the extraction of its flavors - all in all makes for a weak coffee. Although I have no idea as to the effect of this metamorphosis on the caffeine extraction while brewing
    – endrias
    Dec 18, 2019 at 5:03
  • What if you freeze the roasted coffee for some weeks before beginning to use it? Dec 26, 2019 at 3:27

Someone posted a taste test online with several of the popular storage containers. After a week of storage, frozen beans in an airtight bag beat all of them by a substantial margin.

That accords with my personal experience as well. Freeze beans as soon as they are opened (or if you roast your own, roasted). On home roast, don't even let them degas. When you thaw them later, they will degas as if they had been fresh roasted and taste almost as fresh too. I first picked up that technique from Café Vivace in Seattle - back when Schomer was the reigning authority.

I don't have the link to the container taste test, but you should be able to find it with a little surfing.

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