Results 1 to 11 of 11

Thread: Vacuum Bean Storage- advice needed...

  1. #1
    Senior Member
    Join Date
    Apr 2008
    Posts
    777

    Vacuum Bean Storage- advice needed...

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I am trying to work out how to store my beans post roast. I have a vacuum canister with a pump built into the lid (we stock them in my store). It is a great container- but unlike the vacuum bags- its rigid- and when the air is all pumped out the beans are stored at negative air pressure.

    Is this bad for the beans?

    In a bag the air is simply removed and the pressure inside will be around the same as outside. When the beans are in an actual vacuum- could it suck the goodness out somehow?

    I read this blog which seemed to indicate it was a bad idea, but without saying exactly why:

    http://coffeetime.wikidot.com/vacuum...ee-conclusions

    I would have thought no oxygen equals no oxidisation equals good?

    also should beans be left overnight to de-gass- or vacuumed as soon as cool?

    a penny for your thoughts...

  2. #2
    Senior Member Dennis's Avatar
    Join Date
    Feb 2007
    Posts
    4,512

    Re: Vacuum Bean Storage- advice needed...


    I think its a contentious issue Jack. Though from my way of thinking (and I havent tested it), if there is a negative pressure on the beans then it could only hasten the migration of coffee oils from within to the surface. If this is correct, then obviously its not a good thing. ;)


  3. #3
    Senior Member
    Join Date
    Mar 2008
    Posts
    554

    Re: Vacuum Bean Storage- advice needed...

    Lets look at it like this: What are you trying to accomplish with applying a vacuum? The assumption is that you are trying to avoid exposing the beans to oxygen. By applying a vacuum you are pulling the air out of the container, but you are also pulling gasses out of the beans. When the container is opened and air allowed to enter, the partial vacuum in the beans now pulls in air. In essence, what you have done is to marinate the beans in oxygen. marinating meat is sometimes done in this same way using a vacuum..

    The beans can take care of themselves to some extent: if you use a container that can be as filled as much as possible with the beans, it means that most of the air is displaced, so right off you have limited the amount of oxygen available. The beans also give off gasses (mostly CO²) which further displaces oxygen if the container is allowed to outgas a bit.

    Beyond that, removing the oxygen from a container does not stop the chemical changes going on in the bean once they are roasted. The oxidation of the components does not take place in an 0² starved environment, but will do so VERY quickly once oxygen is available. You can prove this with Illy canned whole beans. These taste good on the first day when the can is opened, but after one or two days they taste a month or two old, because they are.

    The only proven way to store roasted coffee and keep it fresh that I have read is to deep freeze them (a standard fridge freezer section is not cold enough).

    If you have to keep roasted beans around more than about two weeks, best advice I give is to fill a number of smaller jars as full as possible and close them after roasting. Crack open the lid after a day to allow excess as to escape, and keep the jars in a cool place out of sunlight and open them one at a time as needed, not opening any jars until the one you are using is empty.

  4. #4
    Sleep is overrated Thundergod's Avatar
    Join Date
    Jul 2006
    Location
    Sydney
    Posts
    10,496

    Re: Vacuum Bean Storage- advice needed...

    I think the same as Dennis but also havent tested it.

    However I have accidentally tested the opposite.

    I had a bag with a faulty valve.
    When I took it out of the cupboard a week later it had ballooned to what seemed almost bursting point.
    The zip lock had been opened by the pressure and it was all held tight by the impulse seal.
    That bag tasted "fresher" than they should have at 7 days post roast.
    Im surmising that the aging slowed down because the CO2 couldnt freely escape the bag.

  5. #5
    Senior Member
    Join Date
    Apr 2008
    Posts
    777

    Re: Vacuum Bean Storage- advice needed...

    thanks for the great detailed answers- and I think there may be something to the marinated bean idea...

    I wasnt thinking of storing these beans for a long time like this- I try to consume as I go so beans dont make it much past 7 days after roasting.

    I was just thinking of vacuuming the beans after they cool- and leaving them for 3 days- before using.

    perhaps I will do a side by side test- some beans just in a jar and some vacuumed...



  6. #6
    Senior Member greenman's Avatar
    Join Date
    May 2007
    Location
    Perth, Western Australia
    Posts
    3,156

    Re: Vacuum Bean Storage- advice needed...

    When I purchased my Rocky grinder I received a vacuum pump container as a bonus. I used it for a while but after reading lengthy discussion on this method of storage and mainly negative feedback I no longer use it and rely on the one-way valve bags for my storage of roasted beans. I bag my beans straight from the cooling rack.

  7. #7
    Senior Member
    Join Date
    Apr 2008
    Posts
    777

    Re: Vacuum Bean Storage- advice needed...

    I have heard conflicting things .... I am conflicted...

    My local roaster said you should air the beans for at least 12 hours... Others have said (like Greenman) that the beans should be bagged as soon as they are cool.

    Another roaster told me a pump vacuum canister is perfect to store the beans for the rest period before drinking...

    and I dont have any of those one way valve bags... :-(


  8. #8
    Senior Member
    Join Date
    Aug 2007
    Posts
    569

    Re: Vacuum Bean Storage- advice needed...

    Quote Originally Posted by 3E223F3F28233924232C2E222B2B28284D0 link=1240664377/6#6 date=1240727986
    and I dont have any of those one way valve bags... Sad
    beanbay is your friend :)
    Or coffeeparts.

    I also used to reuse the ones i got when buying coffee from St Ali for a while

  9. #9
    Senior Member
    Join Date
    Jul 2008
    Location
    Port Fairy
    Posts
    2,993

    Re: Vacuum Bean Storage- advice needed...

    Hi Jack,

    for the sake of another $0.02.

    Oxygen is what causes the quicker degradation of the beans and in particular the volatile oils contained in the beans.

    So removal of Oxygen is desirable and beneficial. This is achieved (by most of us) by use of one way bags where any left over Oxygen is diluted over a day or two by the CO2 coming off the beans especially if you give the bags a squeeze to help loose some gases. See the other thread on storage time vs method http://coffeesnobs.com.au/YaBB.pl?num=1234837789

    Pulling a partial vacuum with a storage device will do a couple of things based on my Uni Chem (a long time ago). It will speed up the degassing of the beans as the beans contain gases held at atmospheric pressures after the roast and cooling stage so when you reduce pressure in the Jar the gas will rush out to equalise with the environment. As well as this degassing I suspect that the oils will also tend to come to the surface of the beans along with the gas so that when you crack the Jar for the first time you expose more of the oils to Oxygen and then re-evacuating the Jar will only accentuate this process. So more of the oils in the beans are directly exposed to Oxygen instead of just the surface layer in the case of atmospheric bags.

    So while you may have reduced the Oxygen exposure I suspect the beans maturation is being changed by the Vacuum process in that as the oils are removed that some of the flavour complexity may be lost prematurely.

    All the above is based on hocus pocus chem so all feel free to pick it to pieces *:)

  10. #10
    Senior Member
    Join Date
    Jul 2008
    Location
    Port Fairy
    Posts
    2,993

    Re: Vacuum Bean Storage- advice needed...

    Had a read of the article you refered to as well and it seems ridged vacuum is out

    When I use the term vacuum packing, I do not mean keeping the beans under reduced pressure, but rather using a flexible bag from which all excess air is sucked out of using a Vacuum pump. Packing the beans in what I would term a "hard" vacuum e.g. rigid container, I think would not be good for coffee. The hard container stores coffee under reduced pressure, a flexible bag does not.

  11. #11
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,770

    Re: Vacuum Bean Storage- advice needed...

    Gday Jack...

    Have you noticed this thread.... http://coffeesnobs.com.au/YaBB.pl?num=1240666086 Looks like a very good system if the guys concerned can get it into production. Not for pre-ground of course... ::)

    Mal.



Similar Threads

  1. Bean storage
    By badbudgie in forum Roasted Bean Storage
    Replies: 5
    Last Post: 16th July 2012, 12:15 AM
  2. Vacuum storage
    By Kes in forum Roasted Bean Storage
    Replies: 26
    Last Post: 15th December 2009, 09:45 PM
  3. Vacuum storage
    By caffeol in forum Roasted Bean Storage
    Replies: 2
    Last Post: 29th July 2008, 08:33 PM
  4. Bean Vacuum
    By BamBam in forum Roasted Bean Storage
    Replies: 8
    Last Post: 20th May 2008, 10:25 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •