# A few questions on de-gassing and whether to use valved or no valve bags



## Robbo (Feb 17, 2016)

My main point being; Do you think it is worth paying the extra for valved bags? The 2 types i am looking at are below..

https://www.thebagbroker.co.uk/bb/bb-wovalve/bb-novalve-250-kraft/250g-box-bottom-bag-with-zip-and-without-valve-natural-kraft.html

and the ones i currently use..

https://www.thebagbroker.co.uk/what-are-you-packaging/bags-for-coffee-80/250bbnkzvrear.html

A few things that concern me are;


Will the unvalved bags burst due to de-gassing? Has anyone actually had any experience of this?

If supplying beans for espresso will using an unvalved bag halt the gassing process so that a bag of beans, say 7-10 days post roast, may not be de-gassed enough to be used as espresso?

If supplying pre-ground coffee would the unvalved bags keep the coffee fresher for longer?

Would storing the coffee in the presence of CO2 (in unvalved bags) negatively affect the coffee?

How long after roasting should it be ground and sealed in the unvalved bags?


Valved bags seem to be the preference but is there any evidence that they are better for the coffee?


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## johnealey (May 19, 2014)

05p difference per bag if that helps









Might be worth taping over the inside and outside of a valved bag you currently have and try it, might possibly be the cheapest way of finding out. @DavecUK wrote a while back on vac bagging that may be of some help in answering your query and I may be wrong but may also have written something on results without valves, either in the home roasting section or on the coffeetime wiki

Hope of help

John


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## hotmetal (Oct 31, 2013)

As above, last time I was at Dave's he was deffo of the opinion that normal heat sealable poly bags (?) were cheaper and better than valve bags. I had a couple of (heat sealed) bags of freshly roasted whole bean coffee in them and they did not puff up whatsoever over several days so I do also wonder how useful these one way valves are. I can't really answer your other more in depth questions but Dave may be able to.


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