Curing Outdoor Cannabis
Controlled storage in sealed jars at stable humidity refines outdoor cannabis after drying.
Growing, buying or possessing cannabis and seeds is legal only in some places. Check the law where you live before acting on this information.
Outdoor curing matters more than indoor because outdoor buds often finish with uneven moisture and chlorophyll buildup. Two weeks minimum for noticeable improvement; four to eight weeks is where most growers report peak taste and smoothness. The 'curing boosts THC' claim is folklore—total cannabinoids are locked in at harvest. What curing does is break down chlorophyll and let moisture redistribute evenly, which is why it's not optional if you want craft-grade flower.
What curing is
Curing is the controlled storage of dried cannabis flower in a sealed container at stable relative humidity (RH), typically 58–62%, for several weeks. During this time, residual moisture redistributes evenly between the interior and exterior of the bud, and chlorophyll and residual sugars break down, improving flavor and smoke quality [1].
Curing is distinct from drying, which is the initial water-removal phase that takes flower from roughly 75% moisture at harvest to 10–15% moisture over 7–14 days [1]. Drying makes the bud shelf-stable; curing refines it.
For outdoor grows, curing is particularly valuable because outdoor buds often finish with uneven moisture (dense colas versus airier lower bud on the same plant), chlorophyll buildup from late-season cloud cover, and environmental contaminants like dust or pollen. A proper cure evens moisture distribution and allows time for chlorophyll degradation.
Why growers cure outdoor flower
Improved flavor and smoothness. Curing allows chlorophyll, residual starches, and other nitrogen compounds to break down gradually, which reduces the harsh, grassy taste of freshly dried flower Strong evidence [1][2]. This is the most consistent and observable benefit.
Cannabinoid stability. THCA slowly decarboxylates to THC and degrades to CBN over months. Cool, dark storage at moderate humidity slows this degradation; warm, humid, or oxygen-rich conditions accelerate it Strong evidence [3]. Proper curing extends the shelf life of potency and effect profile.
Terpene preservation. Sealed storage reduces exposure to oxygen, light, and heat, which slows terpene oxidation and evaporation compared to open-air storage Strong evidence [3].
What curing does not do: it does not increase THC potency. The total cannabinoid pool is fixed at harvest and only decreases thereafter. What changes during curing is the ratio of THCA to THC and the smoothness of the smoke and flavor profile.
When to start curing
Start curing when your dried flower passes the stem snap test: small stems snap cleanly rather than bend, but the bulk of the bud is not brittle or crumbly. Moisture content should be approximately 10–13% [1].
For outdoor grows in temperate climates (Northern Hemisphere), this typically means:
- Harvest in late September through October
- Hang-dry in a dark space at 60–70°F (15–21°C) and 55–65% RH for 7–14 days
- Begin jarring when the stem snap is right
Critical: Do not jar too early. If buds still feel moist or stems bend easily, sealing them creates a humid microenvironment ideal for Botrytis and Aspergillus growth Strong evidence. This is the leading cause of total crop loss during the curing phase for outdoor growers.
How to cure outdoor cannabis, step by step
Step 1: Trim and jar. After drying, trim buds (wet trim or dry trim is a personal choice) and pack them loosely into airtight glass jars. Wide-mouth mason jars are standard. Fill to roughly 75% capacity so buds can shift and air circulates.
Step 2: Monitor humidity. Place a small digital hygrometer inside each jar. Target 58–62% RH throughout the cure. Above 65% creates mold risk; below 55% dries buds excessively and speeds terpene loss Strong evidence [3].
Step 3: Burp the jars. For the first 1–2 weeks, open each jar once or twice daily for 1–3 minutes. This releases excess moisture and allows fresh oxygen in. After the first two weeks, burp every few days to once weekly. If you smell ammonia when opening a jar, that batch has developed anaerobic bacterial growth and must be spread out and re-dried immediately Strong evidence.
Step 4: Optional humidity packs. Two-way humidity control packs (e.g., Boveda 62%) can simplify the process by automatically absorbing or releasing moisture to maintain target RH Weak / limited. They are not required but are useful in dry or very humid climates.
Step 5: Store cool and dark. Keep jars in a cabinet, closet, or cool storage space at 60–70°F away from direct light. Light and heat accelerate cannabinoid degradation and terpene loss [3].
Step 6: Duration. Two weeks is the minimum for noticeable improvement in smoothness and flavor. Four to eight weeks is where most growers report peak quality. Beyond eight weeks, further gains are marginal, though properly stored cured flower maintains quality for 6–12 months Weak / limited.
Common mistakes with outdoor curing
- Jarring too wet. Outdoor colas—especially dense, large ones—can feel dry on the outside while the bud core retains significant moisture. If unsure, give dense buds an extra 1–2 days of hang time or unjar and spread on paper for a few hours to finish drying.
- Insufficient burping in week one. Skipping burps or burping infrequently in the first few days is how mold and bacterial rot take hold. Burst open the jar at least once daily in days 1–7.
- Overpacking jars. Crushing buds together bruises trichomes, traps moisture pockets, and creates internal humidity gradients that promote mold. Loosely pack jars so buds can shift when you shake them gently.
- Long-term storage in plastic bags. Plastic bags trap static that can pull trichomes off, and most are not truly airtight. Acceptable for a few days post-dry; unsuitable for curing.
- Attempting to cure moldy bud. Moldy flower will not improve in a jar and can spread to adjacent buds. Cull visibly affected material before jarring.
- Skipping the cure to save time. Fresh outdoor bud off the hang-drying line almost always smokes harsher and tastes greener than the same bud after a 4–6 week cure. This step separates amateur from craft-grade outdoor cannabis.
Related techniques
Drying Cannabis — the essential prerequisite; curing cannot fix a poorly executed dry.
Curing in Glass Jars — detailed guide to mason jar curing and burping protocols.
Long-Term Storage for Outdoor Grows — vacuum sealing, cold storage, and CO₂-flushed containers for holding cured flower 6 months to years.
Harvest Timing for Outdoor Grows — when you pull the plant sets a ceiling on final quality and cannabinoid profile.
Sources
- Peer-reviewed Das, P.C., Vista, A.R., Tabil, L.G., & Baik, O.-D. (2022). Postharvest Operations of Cannabis and Their Effect on Cannabinoid Content: A Review. Bioengineering, 9(8), 364.
- Peer-reviewed Chen, C., Wongso, I., Putnam, D., Khir, R., & Pan, Z. (2021). Effect of hot air and infrared drying on the retention of cannabidiol and terpenes in industrial hemp. Industrial Crops and Products, 172, 114051.
- Peer-reviewed Milay, L., Berman, P., Shapira, A., Guberman, O., & Meiri, D. (2020). Metabolic Profiling of Cannabis Secondary Metabolites for Evaluation of Optimal Postharvest Storage Conditions. Frontiers in Plant Science, 11, 583605.
- Peer-reviewed Trofin, I.G., Dabija, G., Vaireanu, D.-I., & Filipescu, L. (2012). Long-term Storage and Cannabis Oil Stability. Revista de Chimie, 63(3), 293-297.
- Peer-reviewed Punja, Z.K. (2021). Emerging diseases of Cannabis sativa and sustainable management. Pest Management Science, 77(9), 3857-3870.
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