Get one of these Caliber III hygrometers:

Attachment 289855

Then follow this curing guide:

Quote Originally Posted by Stoned4daze61
Burp the jars when you see moisture forming on the jar. If you can go buy a hygrometer that will help with drying your buds correctly. That way you can monitor the RH inside the jar, if it increases several % an hour, you want to burp them for an hour or two, this can be done with the lid off, or you can put it in a brown paper bag for a more even dry. A 3 week cure is good, month or more is optimal. Heres some more info to help with RH levels if you buy a hygrometer.

Cut the product, trim it per your preference, but don't dry it until the stems snap. Take it down while the stems still have some flex, but the product feel dry on the outside. This is a perfect opportunity to drop the dry-feeling flowers onto a screen and collect prime-quality kief that would otherwise get lost in the jar.

Jar the product, along with a Caliber III hygrometer. One can be had on Ebay for ~$20. Having tested a number of hygrometers - digital and analog - this model in particular produced consistent, accurate results. Then, watch the readings:

+70% RH - too wet, needs to sit outside the jar to dry for 12-24 hours, depending.

65-70% RH - the product is almost in the cure zone, if you will. It can be slowly brought to optimum RH by opening the lid for 2-4 hours.

60-65% RH - the stems snap, the product feels a bit sticky, and it is curing.

55-60% RH - at this point it can be stored for an extended period (3 months or more) without worrying about mold. The product will continue to cure.

Below 55% RH - the RH is too low for the curing process to take place. The product starts to feel brittle. Once you've hit this point, nothing will make it better. Adding moisture won't restart the curing process; it will just make the product wet. If you measure a RH below 55% don't panic. Read below:

Obviously, the product need time to sweat in the jar. As such, accurate readings won't be seen for ~24 hours, assuming the flowers are in the optimal cure zone. If you're curing the product for long-term storage, give the flowers 4-5 days for an accurate reading. If the product is sill very wet, a +70% RH reading will show within hours. If you see the RH rising ~1% per hour, keep a close eye on the product, as it's likely too moist.