URL: https://postharvestreport.com/field-notes/drying-curing
Why cannabis drying and curing is where yield gets won or lost — and how over-drying quietly costs operators up to 5% of saleable weight.
Field Note · 2026
By Jay Evans, CEO, Keirton Inc. — May 12, 2026 · 7–9 min read
Why cannabis drying and curing is where yield gets won or lost.
When facilities get designed, the spotlight goes where you'd expect: lighting, nutrients, genetics. Post-harvest — dry room size, equipment spec, repeatable process — too often gets whatever attention is left over. It's a costly oversight. All the work through veg and flower can be undone with a poor dry and cure. It's like dropping the ball on the one-yard line.
This article is about one of the most common ways that happens: over-drying, and the yield loss that comes with it.
1. Modern flower is denser. Moisture removal has to keep up. Today's growing techniques produce big, dense buds. That density makes it harder to pull moisture out fast enough to stay ahead of microbial growth and off-notes. Many operators think their room is at 60% RH when it's actually 62% or higher.
2. Microbial testing is unforgiving. So growers over-dry as insurance. ASTM standards flag higher microbial risk above 0.63 water activity. Our own testing points to a more conservative line: once flower crosses 0.60 water activity, dense buds in particular pick up subtle funk.
3. Labor is expensive. Trimming wants slightly drier flower. Drop the RH slightly (around 57%) and pull when leaves are just crispy but stems don't yet snap — hand trimmers move roughly twice as fast, and automated trimmers (10x to 100x more productive) become viable.
Roughly half of success with automated trimming comes from the machine. The other half is process: how the flower is dried, when it's pulled, how it's sorted, how the equipment is dialed in for cultivar and density.
It can produce excellent flower in the right hands, but it doesn't solve the labor and automation problem, and doesn't fit the reality of most commercial facilities. The protocol experienced growers are landing on:
The cost shows up in two places. Customer experience: over-dried flower loses the benefits of a proper cure — aroma, mouthfeel, burn quality, stickiness all suffer. Yield: over-dried cannabis can carry up to 5% less saleable weight. At commercial scale, that's tens to hundreds of thousands of dollars in lost revenue per year.
−5% — saleable weight that over-dried cannabis can carry. At commercial scale, that's six figures of revenue walking out the door every year.
Cultivation excellence is table stakes. Producers who treat drying and curing as a discipline — with real equipment, calibrated controls, repeatable protocols, and proper measurement — are winning shelf space, retail loyalty, and broker relationships. The ones who don't will keep losing customers to the brands that do.