# No valve coffee bags...



## YerbaMate170 (Jun 15, 2015)

Recently purchased a bag of Gardelli coffee from a cafe in London and noticed the plastic bag doesn't have a degassing valve on it.

Tried the beans today, around 10 days since being roasted, and first attempt is a bit flat. Obivously, given my surprise at the lack of valve this probably unintentionally impaired my tasting a little, but I'm surprised by this - any ideas if there's a reason for this? Special type of bag that doesn't require a valve?

Anyone who's ordered from Gardelli will know how serious they are about all things and packaging in particular - they used to use some sort of nitrogen flushing in their bags which apparently aided freshness and to my tastes at least, really seemed to work.


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## Stanic (Dec 12, 2015)

I had a bag recently and it certainly had a valve, but rather inconspicuous with tiny holes

however I was not exactly impressed with the roast quality, there were lot of under-roasted beans (foxes as they call them in czech, with the ginger colour)


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## YerbaMate170 (Jun 15, 2015)

Stanic said:


> I had a bag recently and it certainly had a valve, but rather inconspicuous with tiny holes
> 
> however I was not exactly impressed with the roast quality, there were lot of under-roasted beans (foxes as they call them in czech, with the ginger colour)


Interesting, I hadn't considered this as I didn't even know such a type of valve existed, will check with my glasses on!

Funny you should mention, I felt the same when I opened mine - it's a bag of Colombia Quisabony. Strange, because my previous (and only) bag of Gardelli (a bean from Yemen) was one of the best coffees I've ever tried in my life and seemed to be roasted to perfection.


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## Mrboots2u (May 10, 2013)

My local roaster still uses brown paper bags . The coffee still tastes great . Anyway had gardelli coffee before been superb . It's a small thing perhaps it's just playing on your mind as you say .


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## Stanic (Dec 12, 2015)

Compared to Square Miles I have now it really was full of them, at least two to four beans to throw in every 18 g dose..the Sq. M. short stories without issues so far


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## YerbaMate170 (Jun 15, 2015)

Mrboots2u said:


> My local roaster still uses brown paper bags . The coffee still tastes great . Anyway had gardelli coffee before been superb . It's a small thing perhaps it's just playing on your mind as you say .


Well I'm more surprised that they'd take a backwards step, i.e. going from using valves to using bags with no valves - I don't doubt that beans can still taste great in paper bags etc. But yes, I will check if there are tiny valves, as above.


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## YerbaMate170 (Jun 15, 2015)

I checked the bag again and pretty certain there is no valve - you would surely be able to see it from the inside right? It's just lined with foil on all sides, top to bottom, no valve. Again, not saying this is bad... Just curious as to why a roaster would choose this option.


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## DavecUK (Aug 6, 2013)

YerbaMate170 said:


> I checked the bag again and pretty certain there is no valve - you would surely be able to see it from the inside right? It's just lined with foil on all sides, top to bottom, no valve. Again, not saying this is bad... Just curious as to why a roaster would choose this option.


I no longer use my very expensive valve bags, I seal in a non valved food safe polythene bag....the important thing is that the bag is thick enough and absolutely air tight. The results are better than valve bags and I had been taping over the valve holes in those for a year before I finally stopped using them.


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## NAJB (May 19, 2017)

I had been contemplating the use of non-valved bags and then stupidly, in hindsight, ordered a new pack of valved bags. I could just bag up the results of all my trial roasts with the new roaster. That would help me get through them.


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## RDC8 (Dec 6, 2016)

From what i understand, the one-way valves allow the post-roast CO2 to escape, while preventing air getting to the beans and causing them to go stale. Without the valve, the sealed bag would swell up from the increased pressure from the released gas, but air would still be prevented from getting to the beans. I did read an article claiming that the one-way valves make sense only to large commercial roasters who look to pack multiple packs of beans tightly into boxes for transport.

As long as the bag is tightly sealed against the air, and strong enough to withstand a little expansion without splitting, then the lack of a one-way valve shouldnt be a problem. Beans sold in a non-sealed paper bag should probably be re-housed in a suitable airtight bag/container asap!


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## DavecUK (Aug 6, 2013)

RDC8 said:


> From what i understand, the one-way valves allow the post-roast CO2 to escape, while preventing air getting to the beans and causing them to go stale.


I agree with your whole post except for this bit.....and I would alter it thusly:

*The one way valves allow CO2 formed (due to air exposure) after roasting to escape, unfortunately air does seem to leak back through the valves causing further CO2 to be formed, the valves also allow a loss of volatiles, all which accelerates staling and reduces flavour.*



*
*This is what I believe, because well sealed bags don't swell much at all if packed very quickly after roasting.


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## YerbaMate170 (Jun 15, 2015)

DavecUK said:


> I agree with your whole post except for this bit.....and I would alter it thusly:
> 
> *The one way valves allow CO2 formed (due to air exposure) after roasting to escape, unfortunately air does seem to leak back through the valves causing further CO2 to be formed, the valves also allow a loss of volatiles, all which accelerates staling and reduces flavour.*
> 
> ...


That's interesting - it's true of course that even after squeezing the CO2 out of a valved bag, the next day you'll have more gas inside... But I just assumed this was more C02 being given off by the beans rather than gas having gotten back into the bag. After all, the whole point of a one-way valve *should* be that you don't get gas in... But yeah I hadn't considered that the valves aren't fully effective.


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## DavecUK (Aug 6, 2013)

YerbaMate170 said:


> That's interesting - it's true of course that even after squeezing the CO2 out of a valved bag, the next day you'll have more gas inside... But I just assumed this was more C02 being given off by the beans rather than gas having gotten back into the bag. After all, the whole point of a one-way valve *should* be that you don't get gas in... But yeah I hadn't considered that the valves aren't fully effective.


Well the proof is in the results, when I seal my non valved bags, if they produced as much gas as a valved bag does (cos I've squeezed a valve bag like you and the same thing happens)...*my bags would puff up like balloons, but they don't.* I also double and triple checked leaks...even put them underwater and squeeze.

Oh I also taped up the valkve in a valve bag and this reduces CO2 formation as well, although I think it can still leak a bit past the tape. I would like to find some thick black polythene, but unfortunately, it's not done in food grade.


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## Robbo (Feb 17, 2016)

I did a bit of experimenting with this a few months back and found that when i bag into polythene airtight food bags an hour after roasting i get very little swelling and the coffee stays fresher for longer. This would be good if storing for long periods.

I also found no real difference when using valved and unvalved craft bags. In both cases the bags rarely swelled at all except with dark roasted beans. Monsooned malabar for eg. and in that case both valved and non valved swelled. which led me to believe the valves are not really that effective. It seems they need a bit of pressure before releasing C02

If i am using them for espresso i want them to rest for 7-10 days in bags which are not completely airtight. If i store them in the airtight freezer bag i get inconsistent shots, which i put down to them not degassing properly. They act as if i used them the day after roasting. This is also evident with the increased bloom when i use them in a drip filter although this isnt a problem with drip brews.


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## DavecUK (Aug 6, 2013)

As long as by airtight you mean heat sealed, not just ziplocked...cos ziplocks are quite leaky.


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## "coffee 4/1" (Sep 1, 2014)

Gave up on bags valve or no valve most leak anyway especially the foils at seams,know theres 101 ways to not have stale, my take is, roast 500g degas for 4hour box up into 60gms into freezer, when needed take out one box decant to the

mini Prepara-evak jar, does me for the day, thats the freshest i can do with the least faff, or you can just use a evak medium or large jar without freezer.


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## Chris_on_caffeine (Jul 21, 2012)

Im pretty sure valves are only there to stop the bag splitting. Clever marketing has made them into a 'thing'.


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## Guest (Aug 16, 2019)

Gardelli only uses valves on its coffees roasted for espresso, all coffees roasted for filter do not have valves on as they do not need to degas like the espresso roast, the CO2 contained in the filter bag helps to maintain the life of the coffee also


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