A humidity pack is a sealed pouch of saturated salt solution behind a vapour-permeable membrane. It absorbs or releases water to pull a closed container's air toward a set RH, commonly 58% or 62%. "Two-way" means it can both add and remove moisture.
In practice
They are widely sold for jars and storage. GenetixBay doesn't recommend them.
House position (Myth for the quality claims): - They are a marketing gimmick. The pro-pack data is essentially the manufacturer's own. - They rob terpenes: the pack and its membrane give the jar's volatiles somewhere else to go. - Curing is a slow decline in moisture, not holding moisture constant, which is exactly what a pack is designed to do.
If buds are too dry and you need to add moisture, put a fresh bud in the jar instead. To keep stock in range, start with a good dry, fill airtight glass jars well, and store them dark and cool.
Don't confuse with
- Desiccant: removes moisture only, for seeds and electronics.
- Hygrometer: measures RH, doesn't control it.
- Water activity target: the goal (0.55-0.65 aw), not a product.
Myth check
"Humidity packs keep your stash fresher" is a Myth in the house view. A well-dried, well-cured bud in a full, airtight, dark jar does the job. See curing and burping and Mythbusters.
