Article - How To Make Homemade Desiccant for Long-term Storage

[TWP]

Method #1 uses drywall, which will be available in a Post Apocalyptic World because some many buildings use drywall construction...  Remember this when you need desiccants.

They are easy to process into a long lasting (and "rechargeable") canning and storage necessity.  The desiccant packs can be re-heated to drive off the absorbed water and stored in air-tight containers.

http://prepperswill.com/make-homemade-desiccant-long-term-storage/

The other two methods rely on the availability of products which will probably NOT be manufactured anymore...