Thank you Daren.
It matches my assumption (I didn’t quite remember if it goes up or down) that as the reeds become wet, and as most of the moisture goes around the tip of the reeds (at the opening), then the reeds become heavier and therefore vibrate slowly (lower freq).
So how do you perform the several-cycles tuning? Warming it up again before every cycle, or are you that good at it that you only require one cycle? 🙂