Drying is the process of removing excess moisture from freshly harvested cannabis flowers to prepare them for preservation and consumption. At harvest, the plant material is composed of approximately 75 to 80% water by weight, which is too high for safe storage. This moisture must be reduced to prevent the growth of mold and harmful microbes. A controlled drying process is the most significant step between harvest and use, as it directly determines the final quality, potency, and flavor profile of the flowers.
Establishing the Right Drying Environment
The goal of drying is a slow, controlled reduction of moisture, requiring precise environmental conditions. Maintaining a consistent temperature between 60 and 70°F (15 to 21°C) is ideal. Temperatures above this range cause water to evaporate too quickly, leading to a harsh smoke and a loss of aromatic compounds known as terpenes.
Relative humidity (RH) should be managed to stay within a range of 45 to 55%. If the air is too humid, the drying process stalls, increasing the risk of mold and mildew development. Conversely, if the air is too dry, the exterior of the buds can become brittle before the interior moisture has fully escaped, leading to an uneven dry.
The drying space must be kept dark, as exposure to light can degrade cannabinoids like THC. Gentle, consistent air circulation is required to facilitate the slow evaporation of water vapor. Air should move throughout the room without fans blowing directly onto the flowers, which accelerates drying too much. These stable conditions preserve terpenes and cannabinoids, allowing physical indicators of readiness to appear over the typical 7 to 14-day period.
Physical Indicators of Dryness
The most reliable way to tell if drying is complete is by using the physical “snap test” on the branches supporting the flowers. This test is performed on the small, pencil-sized stems that run through the buds, not the main stalk. A properly dried branch should snap cleanly and audibly when bent sharply, indicating that the internal moisture has been sufficiently removed.
If the small branch bends or folds over without a clean break, too much moisture is retained, and more drying time is necessary. A common mistake is testing the largest stems, which retain water longer and may still be flexible when the flowers are ready. Focus the snap test on the smaller stems closest to the flowers for an accurate assessment of dryness.
In addition to the auditory cue of the snapping stem, the flowers should be assessed by feel. Gently squeezing a bud should reveal a dense, firm texture that is neither squishy nor brittle. The exterior should feel dry to the touch, but the structure should not crumble when light pressure is applied.
The small leaves tucked into the flowers, often called sugar leaves, offer a visual and tactile indicator. These leaves should be completely dry and crispy, easily flaking away from the bud structure. If these leaves still feel soft, pliable, or contain noticeable moisture, the flowers have not reached the appropriate level of dryness.
Moisture Content Targets and Transition to Curing
Once the physical indicators are met, the flowers have reached the endpoint of the drying phase. This corresponds to an internal moisture content of 10 to 12% by weight. This range is low enough to prevent mold growth but high enough to preserve the integrity of the trichomes, which contain cannabinoids and terpenes.
If the flowers dry beyond this 10% range, the material can become brittle, leading to a harsher smoking experience and a loss of terpenes. The completion of the drying phase means the flowers are ready for the next step: curing. Drying is primarily about rapid water removal, while curing focuses on chemical refinement and moisture equalization.
The transition to curing involves moving the dried flowers into airtight containers, most commonly glass jars. The goal is to stabilize the remaining moisture content where the internal relative humidity inside the container settles between 58% and 62%. This humidity level is necessary for chemical reactions that break down residual compounds, such as chlorophyll, enhancing the flavor and smoothness of the final product.
Moving the flowers immediately to airtight containers prevents them from continuing to dry out and locks in the final state of the material. Achieving the physical indicators of dryness prepares the flowers for the curing process, where the remaining moisture equalizes throughout the buds for a consistent, high-quality final product.