The 60/60 rule is a popular drying guideline: hold the drying room around 60 °F (about 15.5 °C) and 60% RH. At those settings, buds lose water slowly and evenly, usually reaching jar-ready in roughly 10-14 days, depending on bud density and how much stem and leaf is left on.
In practice
The rule works because it slows evaporation from the bud surface to match the rate water can move out from inside. That avoids case hardening, helps chlorophyll break down, and keeps more of the volatile monoterpenes that are lost fastest in warm, fast dries.
It is a target, not a law. Many growers run 60-68 °F (15-20 °C) and 55-62% RH with good results. What matters is a slow, even dry with no mould. Adjust for your material:
- Wet trimmed, small buds: stay at the cooler, more humid end.
- Whole-plant hang, dense colas: watch mould risk; a little lower RH or more air movement may be needed.
Measure at bud level with a calibrated hygrometer. Room-corner readings can be several points off.
Don't confuse with
- Jar RH targets for curing: a proxy for water activity, a separate measure.
- Water activity: the bud's own measure of available water.
- VPD: a growing metric, not a drying rule.
A dark, ventilated space where freshly harvested cannabis is dried under controlled temperature, humidity and gentle airflow, usually for 7-14 days.Relative humidity is the water vapour in air as a percentage of what it could hold at that temperature, so the same RH dries plants differently at different temperatures.A drying fault where a bud's surface dries too fast and seals, leaving the core wet; buds feel dry, then rehydrate and risk mould in the jar.The green pigment in chloroplasts that absorbs mainly blue and red light to drive photosynthesis; chlorophyll a and b are the main forms in plants.A monoterpene is a ten-carbon terpene made from geranyl pyrophosphate, such as myrcene, limonene, pinene or terpinolene; they are the most volatile terpenes and the first lost in drying.Drying an entire harvested plant upside down, uncut except at the base, so the large stem mass slows the dry.A 0-1 measure of how freely available the water in a material is; for dried cannabis flower the accepted range is about 0.55-0.65 aw.Vapour pressure deficit: how much more water vapour the air could hold at its temperature, in kPa; it is the main environmental driver of transpiration.Drying harvested cannabis by hanging branches upside down in a dark, controlled room so buds dry slowly with even airflow around them.The loss of volatile aroma compounds from cannabis through evaporation, oxidation and handling, fastest for monoterpenes and worst in warm, fast drying and poor storage.
