I've been reading a wikipedia article about the best material for a coffee jar for storing beans, which recommends ceramic or dark glass. I then came here and there is a recent question about aluminium packaging for preserving beans. This makes me a little confused, because I thought that aluminium, i.e metal, would affect negatively the taste of the beans. Then I read that ceramic can contain a large amount of lead, which makes me even more concerned.

If you were thinking about the perfect storage for your beans, what would be your material of choice? Thank you.

2 Answers 2


Typically aluminum packaging is actually a three (or more) layered packaging with aluminum not being in direct contact with the beans. Aluminum is a superb barrier to air, and it is typically used as an internal layer to prevent air transferring into the bag, without being in direct contact with the beans.

Keys to optimal packaging:

Prevent light from reaching beans. Light will help to speed oxidation of coffee oils.

Prevent air from reaching beans but don't restrict air from escaping beans! This is where the 1 way degassing valve comes in. Coffee will offgas carbon dioxide if it is fresh. High CO2 levels contribute to oxidation, so you want the ability for that gas to escape without constantly recirculating air in your container (which would also contribute to oxidation).

I think ceramic or dark glass would both be excellent storage solutions provided they have a way to degas the coffee. These materials (provided they have good methods of sealing the container) would prevent air transfer into the coffee, and would sufficiently block light to prevent oxidation.

An example of an aluminum coffee bag I snagged from the internet has a PET internal liner, Aluminum barrier layer, and an LDPE external layer. So.. basically aluminum sandwiched between foodsafe plastic and something that looks good on a shelf =p

  • Thank you Nate. I have seen a rising number of people shying away from plastics, despite them being classified as food safe. So the fact that you're positive to a ceramic material is encouraging. Thank you for your answer. Commented Apr 29, 2017 at 9:29
  • Just a note on the ceramic piece.. food safe ceramics are probably glazed, and don't use lead. Just look for food safe. Kind of the same thing as the really old orange fiestaware that used Uranium in the glaze. You can just google food safe ceramics and get a ton of results. If it is a major concern, just go with glass. Personally, I go through too many batches of coffee to make glass or ceramic feasible, so I just use bags.
    – Nate M.
    Commented May 1, 2017 at 22:09

Perfect and optimal are are not the same. And optimizing many factors.

In transportation the are other factors - mainly transportation. Glass is relatively expensive, bulky, heavy, and fragile compared to aluminum packaging. Slight less preservation does not make up for all the other advantages of aluminum for transportation.

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