I have a question that I haven't read about. On the bags that my beans are shipped in, there is a one way valve, most likely to keep the bag from rupturing while the beans outgas. When I get them, I typically transfer the beans to Ball jars and seal them. When I open the jar, I can hear the gas rush out. I wonder if having the beans sit in gas that's pressurized has any affect on taste? I also wonder if keeping the beans in an air tight container slows the outgassing process?

I think that's "no" and "no".

barry wrote:I think that's "no" and "no".

Thanks, and if that's true, then do I even need to store my fresh (not frozen) beans in the Ball jars? It definitely is easier to just leave the bags alone until I use them.

Just thinking out loud. In a soda, the CO2 can't be released until you open the top and release the pressure. Once the CO2 is let out, the soda gets flat. You could imagine a pressurized container with coffee beans (how pressurized? good ?). Open the top and the CO2 is released, not just out of the container but it may keep the CO2 trapped in the beans! When the CO2 is gone from the beans the crema goes flat just like a soda. I can just see it now- roasters will pack their beans in 15g containers that they will fill with pressurized CO2 and keep the beans super fresh, or even add CO2 artificially!

But seriously, can the CO2 be kept in the beans with pressure???

I don't think there's any real benefit to keeping the CO2 in the beans, except to keep O2 out of them to prevent staling.

Illy and others do use pressurized packaging to keep their beans fresh--usually N2O--but it's been reported that while the beans taste great the first day, they quickly degrade. This is fine if your a cafe who opens a handy can of Illy and dumps it in a grinder assured it'll be gone that day or the next, but for a home user this is a bit of a problem.

Isn't it often mentioned that CO2 enables the transportation (e.g. as a solvent) of flavours and lipids from the coffee to the water?
Is this not accurate?