Vacuum Bagging Fresh Roast Coffee Beans

On the commercial coffee LinkedIn group, there was a question on vacuum packing freshly roasted coffee to keep it fresh. When I was at roasting school, we learned how freshly roasted coffee gives off CO2. This is why you need a can or bag with a gas relief valve. Recently, I decided to get a hand vacuum bagging system. It is a low-cost unit available in Canada from Home Hardware for only $20. For a small cost I could experiment with vacuum packing coffee. The bags are reusable but not cheap, at about $1.25 each. As I just want to use the bags for my coffee at home, the price per bag is not a factor. If the coffee was for resale, a much lower cost per bag would be needed.

Vac N Store system from Home Hardware

The Vac N Store kit comes with three bag sizes. My sample roaster does 1/2-pound roasts that fit nicely in the small bag. By sealing the bags, the coffee is not exposed to oxygen, which is what contributes to making coffee stale. What surprised me was how much gas is released by the beans. Here is a bag of just-sealed, freshly roasted coffee. The little hand pump does a fair job of removing air, but is not commercial grade.
Vacuum bagged coffee

Here is the bag 5 days later.
Vacuum bag with released CO2

I was surprised how much air was in the bag. This is not from leaking. Here is a large bag of decaf green coffee beans that I packed several weeks ago. The vacuum seal is still tight.
Decaf Green coffee beans in vacuum bag

I put the bagged roasted coffee in my grinder this morning, and it was very nice. Did it hold the freshness better? I am not sure. I need to do a side-by-side on the same coffee, one roasted a week ago and stored, the other roasted the day before.

My question coming out of this is how do companies like Illy vacuum pack coffee? I believe theirs stays tightly packed because the coffee is ground. Perhaps on the next roasting batch, I will bag 1/2 as beans and in a second bag, 1/2 ground and see how it compares.

12 thoughts on “Vacuum Bagging Fresh Roast Coffee Beans”

  1. I found some interesting technical papers on CO2 release from freshly roasted coffee. Grinding opens up the cells releasing more gas and exposing more surface area. Depending on how fine the grind CO2 will be released for 12 to 24 hours. The finer the quicker it is released. Whole bean coffee takes around 7 days to degas.

  2. Rich,
    Sivetz did extensive research (and practiced) inert gas flushing, vacuum sealing, and deep freezing of freshly roasted coffee. He apparently patented it http://www.sivetzcoffee.com/preservation_patent.htm. You may not need to do the experiments yourself, especially, he contends, as even commercial vacuum sealers do not pull sufficient vacuum to reduce oxygen to levels needed for storage without oxidation.

    My own theory is that the other, equally important, aspect of coffee staling has to do with the loss of volatile aromatics. This is not served well by the common one way degassing bags, as these precious compounds are allowed to escape freely. Not a good thing!

    There is a product called an oxygen absorber. http://oxygenabsorbers.ca/ In theory this would allow packaging in a non-valved bag, and without the need of vacuum sealing. I wonder has anyone tested these for coffee.

    1. Mark. Thanks. The links are interesting. Oxygen absorbers would not eliminate the CO2 given off by the beans so the bags would still swell up. I am looking to see if any work has been done where the freshly roasted beans are subjected to a vacuum for some time to help pull the CO2 out. Mind you the volatile aromatics would be removed also.

      One challenge I find is so many sites have advertising in the form of what appear to be technical papers pushing their form to keeping coffee fresh. I think doing actual experiments might be how to get a handle aspects of this. As an example if volatile aromatics are important, submitting beans to a strong vacuum for several hours then cupping those beans vs non-treated beans could be revealing.

      My fear is many articles are pushing their agenda vs scientific facts.

  3. Hi Rich,
    Did you try to pull a vaccum (again) on the package with the CO2 gas in it, i.e., remove the CO2 – after the roasted coffee de-gassed?
    Thanks.
    Dave

  4. Yes then the vacuum held pretty well. Even with a medium grind I found by 24 hours the degas was done. What was interesting was I made coffee this morning with the ground coffee that was stored. This ground coffee was 5 days old. I was surprised how good the coffee was. I need to do a side by side cupping on the same coffee, same roast with one ground and stored a week and the other just ground to see how they compare.

  5. I have been doing a lot of reading on coffee degassing. There are several good academic papers on it. The CO2 is escaping from the small cavities in the bean. When the bean is ground many of these cells are broken open. One paper estimated 45% of the CO2 is released in grinding. Once ground the CO2 degasses in 12-24 hours depending on how fine the grind is.

    Most companies who are going to vacuum pack the ground coffee store the coffee in a nitrogen flushed environment to prevent oxygen staling.

  6. I do not know if it helps anyone, I have a small coffee distributing company in New York we do about 1000 pounds of ground coffee a week. we also use a non venting, heat sealed bag and have had no problems with freshness or swelling. We grind the coffee to a medium grind and put it directly into the bag. After doing this we let the coffee sit in the bag open for 24 hours and then seal it. I wonder if anyone knows if the darker or lighter you roast the coffee, does this affect the degassing period?

  7. Hello to All,

    Guys you are all superb informative. Thanks so much for sharing it to me.

    More power to your website and God Bless!!!

    Indeed you are so helpful!

    PS. I like the design of Coffe Troupe with alive n kicking heads of beans

    Luv you all

    Divine

  8. I’m intrested in the research work done. Im a farmer of Arabica Coffee in Uganda. Of recent we have opened up a market stall in the UAE. We might need your product in future.

    Regads

    Yaqub Manafa

    1. Yaqub
      I don’t sell those. I just bought it to do the research at a local store. If you wanted to do vacuum packing there are many solutions. If your customers are going to consume the coffee within a few weeks there is no need to vacuum pack.

  9. At present we are only sampling grean coffee beans. We plan to sttartt with a pack for roasted coffee beans. A machine ans paper is sought. Thank you for these good inovations.

  10. Kindly I need Vaccum bags for Coffee parkaging for my small business of export from Tanzania East Africa

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