Thanks to all. I see that I am probably worrying too much. My interest depends also on the fact that if I like Rollei CN200 (or CR200) I can find very cheap bulk rolls of both products and I wondered about refrigerating an open bulk roll.

I like the rice trick.

I don't know what a "descant" is in this context (unless I have to find a contratenor and put him in the fridge, but it seems impractical ).