This may be a controversial opinion, but i believe freezing coffee beans is a perfectly valid preservation technique, if you only take care to avoid any contact with humid air.

That means freezing in air-tight, evacuated bags, and bringing up to room temperature completely before opening the bag again.

Edit: There's a [new video by coffe guru James Hoffmann][1] out, where he basically says the same things as i did here. I feel vindicated :)


  [1]: https://youtu.be/5uT5_IWWb00