Could be the ambient humidity. My humidors have been sitting at 68-69 with new 65% bovedas, even the well sealed Sistema tupperdore because of all the rain we've gotten in the last 2 weeks. The ambient humidity has been between 80 and 95 and bovedas don't absorb and dehumidify as fast as they humidify.

Well, they both tested within one percent of 75, and or ambient RH is in the single digits, so I dunno...

I've never salt tested, normally I just use a 72% pack. I assume 75% is the target for that test?
If that's the case, I suppose I'd just say it's time to replace. Maybe they really do have a finite life to them.


Now another thought, pull them out for a few days and let them sit on the counter or even in some old boxes where they can give up some humidity. Possibly that could allow them to start taking up again.

OK, so I salt tested both. They were both within 1% of 75, so that seemed good and I calibrated them (they are adjustable). Then I stuck one in a zip lock for 12 hours with a 62% boveda and it reads 69%... FFS.

If you have any higher % boveda use those instead. And find an unused pack since your questioning the ones you're currently using.

Well, thats the thing... My initial suspicions over the high (68-69%) reading were while sitting in with older 65% bovedas, so I bought some brand new 62% packs and, after calibrating the hygrometer with salt, stuck it in a zip lock with a brand new 62%. It still reads very high.

I am going to try fresh batteries next and see if I can get a different result.

Old 65% bovedas in humidor - Read 68-69%
Salt test 24 hours - calibrated to 75% (was only off one or two %)
New 62% boveda in zip lock - 68%

Hmmmmm
I'm of the trust the boveda camp, but your readings are over threshold which would make me think your salt test would have been over as well, but it's not. I'm as stumped as you.

12 hours might not be long enough Stogie.
Do it for 36+ hours….maybe even 48.

Try it with a load of cigars for 24 hours. That’s how they’re designed for use after all.

Well, the plot thickens...

After salt calibrating, both hygrometers read +/- 1% on my old 65% packs, as well as on a handful of the smaller 69% ones the shops send deliveries with. The brand new 62% packs are the only ones now reading 5+% higher than the printed value. Anyone ever get a bad batch of 62% Bovedas?