Why Are HCM Beads Better Than PG and SAP?
When PG is combined with water or SAP (Super Absorbent Polymer), its hygroscopic properties are instantly defeated because you have just created a saturated solution. Saturated as in “I can no longer gather water because I am saturated, thus PG is no longer hygroscopic until the absorbed water has been reduced below its capacity to hold water. Mixed with water or SAP, PG will only release water at a rate equal to 70% RH. That is good because in a saturated solution you can control the release of water, holding it at 70%. So in this instance, you’ve got a great opportunity to use it where a lot of water is needed to maintain a humidor. This makes PG and SAP a good choice for very dry places or leaky humidors.
