Hang drying occurs immediately following harvest, bridging the gap between a fresh plant and a consumable product. The primary goal is the controlled removal of moisture, as freshly harvested cannabis contains 75 to 80% water by weight. This high water content makes the material susceptible to mold and mildew. Reducing moisture stabilizes the plant, preserving the cannabinoids and aromatic terpenes that define the final product’s quality. A proper, slow dry is necessary for a smooth experience, as rapid moisture loss can trap compounds like chlorophyll, leading to a harsh taste.
Optimal Environmental Conditions
The drying space environment is the most influential factor determining the success and duration of the hang dry process. Maintaining a stable temperature range is necessary, with experts recommending between 60 and 70°F (15–21°C) to prevent degradation of delicate compounds. Temperatures exceeding this range cause the flower to dry too quickly, leading to a harsh final product and the rapid volatilization of terpenes, which carry the plant’s aroma and flavor.
Relative humidity (RH) is equally important and should be maintained between 45% and 55% during the drying phase. If humidity falls below this range, the flower dries too fast, potentially becoming brittle outside while retaining internal moisture, leading to a loss of quality. Conversely, RH above 60% substantially increases the risk of mold and fungal growth, which can destroy the harvest.
Gentle, consistent air circulation throughout the drying space is necessary for an even dry and to prevent pockets of stagnant, humid air. Airflow aids in carrying away the moisture the buds release into the environment. However, fans should never be pointed directly at the hanging flower, as direct air movement causes the outside of the buds to dry much faster than the interior, resulting in an uneven and lower-quality product.
Factors Influencing Drying Duration
Under controlled environmental conditions, hang drying generally takes between 7 and 14 days, though this timeframe is influenced by several variables. This duration is preferred because a slower dry allows for a more gradual breakdown of undesirable compounds, resulting in a smoother final product. Growers sometimes extend the drying time closer to 14 days or longer to maximize the preservation of volatile terpenes and overall flavor.
One primary factor in drying duration is the density and size of the individual flowers. Denser, larger buds naturally contain more internal moisture and require more time for water to escape, often needing the full two weeks or more. Smaller, fluffier flower structures have a greater surface area relative to their mass, allowing for faster moisture evaporation and a shorter drying time.
The extent of trimming performed before hanging also affects the timeline. A wet trim, where most sugar and fan leaves are removed immediately after harvest, reduces mass and surface area, causing the flowers to dry more quickly. Conversely, a dry trim involves leaving most leaf material intact during the hang dry, slowing the process by acting as a protective barrier and contributing to a higher quality final product. Strain genetics also play a role, as some cultivars are naturally more resistant to moisture loss than others.
Practical Tests for Readiness
Determining when the hang dry process is complete relies on specific physical tests indicating the internal moisture content has reached the target range. The industry standard for readiness is 10% to 12% moisture content, which is necessary before moving the flower into the final curing stage. If the flower is put into sealed containers too early, remaining moisture will lead to the growth of mold and anaerobic bacteria.
The most common field test is the “snap test,” which focuses on the rigidity of the small stems and branches within the flower clusters. When a bud is ready, the small, thin stems should snap cleanly when gently bent, rather than just bending or feeling pliable. If the stems bend without breaking, it indicates too much moisture remains inside the plant material, requiring more drying time.
For the highest accuracy, using a wood moisture meter is the most reliable method for confirming readiness. By inserting the probes into the densest part of sample buds, the meter provides a precise, objective reading of the flower’s moisture content. Growers aim for a reading in the 10% to 12% range, confirming the flower is stable and ready to be transferred to an airtight container for the curing process.