I roast coffee, and currently package it in plastic bags with one way 'degassing' valves.
As soon as coffee is roasted, it starts giving off $\ce{CO2},$ a process which continues for days, and sometimes weeks. The degassing valve allows the $\ce{CO2}$ to escape the bag, while it prevents oxygen, which is the staling enemy of coffee beans, from entering the bag.
I fold the top of each bag over with three folds and then tape it with a piece of tape.
Due to composting concerns (the valves are not compostable) I would like to stop using the valves and package the coffee in plain bags with the three folds and piece of tape. My theory is that the pressure of the off-gassed $\ce{CO2}$ will allow it to escape out of the three folds at the top of the bag, and that the oxygen not being under as much pressure from the outside, will not find it's way into the bag for a long time (months, hopefully), thereby maintaining a $\ce{CO2}$ flush of the beans in the bag, which prevents them from staling.
Does this seem like a plausible, likely scenario to keep the beans fresh, by keeping the oxygen away from the beans, allowing the $\ce{CO2}$ to escape under the initial pressure, and then maintaining the $\ce{CO2}$ environment in the bag?
Your informed answers are appreciated.