The process of drying cannabis flower after harvest transforms the raw plant material into a stable, usable product. This procedure involves carefully reducing the total water content to ensure quality and safety. The goal is an internal moisture content typically between 10% and 15%, with 10% to 12% considered ideal for long-term storage and curing. Determining readiness requires a combination of sensory assessment and technical measurement.
Why Achieving Proper Dryness is Crucial
Allowing the flower to remain too wet carries significant risks, primarily related to microbial contamination and product degradation. If the moisture content stays above 15%, the material creates an ideal environment for the proliferation of mold and mildew. This contamination can render the product unsafe for consumption. The presence of mold, such as Botrytis (bud rot), is a serious safety concern, especially for those with compromised immune systems.
Improper drying also severely impacts the sensory quality of the final product. Moist cannabis will not burn cleanly or smoothly, often resulting in harsh smoke. Delicate aromatic compounds known as terpenes can degrade or be lost if the drying process is too fast or uneven. Conversely, if the flower is dried too quickly or too much, the material becomes brittle and harsh, reducing potency and flavor complexity.
Practical Sensory Tests for Readiness
Growers rely on simple, practical tests that assess the flower’s physical state to determine if it is ready for the next stage. The most common of these is the stem snap test, which focuses on the structural integrity of the small stems holding the individual flowers. These small stems should snap cleanly with a distinct crack rather than bending or remaining flexible when gently folded.
The snap test should only be performed on the smaller stems connecting the buds to the larger branches. Larger main branches often retain flexibility even when the flowers are dry. If the smaller stems bend instead of breaking, it indicates too much residual moisture remains.
Another reliable indicator is the flower squeeze test, which involves gently compressing a dried bud between the thumb and forefinger. A properly dried bud should feel firm and slightly springy, but the outer layer may feel dry or slightly crispy. The flower should not feel spongy or wet, nor should it instantly crumble into dust, which signals over-drying. A change in smell also signals readiness, as the initial strong, “grassy” odor dissipates, revealing the complex aroma of preserved terpenes.
Using Tools for Precise Moisture Reading
While sensory checks provide a useful estimate, instruments offer a precise, quantifiable measure of dryness. The most common tool for post-drying quality control is the hygrometer, which measures relative humidity (RH). Hygrometers are placed inside a sealed container, such as a glass jar, alongside the dried flower.
The RH reading inside the sealed container directly correlates with the flower’s moisture content. An ideal reading for the curing stage is between 58% and 62% RH. If the reading quickly rises above 65% RH after sealing, the flower still contains too much internal moisture and requires more drying time.
Some growers also use wood or grain moisture meters for a rough numerical estimate of the water percentage. Although not specifically calibrated for cannabis, they provide a quick, comparative reading of the stem’s moisture. Industry standards aim for a moisture content of 10% to 12%, ensuring stability and quality.
Transitioning from Drying to Curing
Once the flower passes the sensory and technical tests, it transitions to the curing process. Curing is controlled storage aimed at equalizing internal moisture and allowing the slow breakdown of unwanted compounds, such as chlorophyll. This process improves flavor and smoothness.
The first step is placing the dried flowers into airtight containers, such as glass mason jars, filling them about three-quarters full. This jarring allows moisture remaining deep within the buds to migrate outward, creating a uniformly moist environment. This equalization prevents mold while preserving terpenes.
The containers must then be opened periodically, known as “burping,” to release excess moisture vapor and replenish the oxygen supply. Burping prevents the buildup of anaerobic conditions that can lead to unpleasant, “off” flavors. Monitoring the relative humidity and burping as needed stabilizes the flower for long-term storage and develops its full aromatic potential.