Most old-school growers don't use a hygrometer we go by feel or whatever. See when I go to snap, nice crispy outsides, trim, then put it in the jar, it is always way too moist the next day. That's why you burp. But you can tell that it got moist again. In order to smoke that you pull a bit out and let it dry a while or wait a month+ for it to cure. Curing is good because it further breaks down your unwanted chemicals like chlorophyll and produces a smoother smoke, but it doesn't actually make your buds more loud.
The main reason I jar personally is to keep all the terps in. Now you can hang your stuff in the perfect conditions and air cure for a month or more but your volatile terpenes will float away in the breeze.
If it wasn't for that I wouldn't jar because it makes my buds too wet for a month.
That being said I've went to snap and still had to wait 2 months for it to cure.
Also everyone with good weed goes to snap.
I mean everyone.