Curing is the final, controlled post-harvest process that significantly refines the quality of harvested cannabis. This step occurs after the initial drying period, allowing the flower to develop its ultimate characteristics. Proper curing dramatically improves the user experience by ensuring a smoother inhale and a richer flavor profile. The slow, gradual changes lock in aromatic compounds and enhance potency. Skipping this step results in a harsh product with diminished aroma and a shorter shelf life.
The Science Behind Curing
Curing is a process of controlled degradation and chemical transformation that removes unwanted compounds and preserves desirable ones. The harsh, “grassy” taste comes from residual plant matter, particularly chlorophyll and primary metabolites like sugars. During the cure, enzymatic activity continues, slowly breaking down these compounds. The reduction of chlorophyll creates a smoother, less irritating smoke, allowing the flower’s true flavor to emerge.
This slow breakdown must be managed carefully to prevent the degradation of delicate compounds. Curing conditions are designed to preserve aromatic terpenes, which are highly volatile and responsible for the unique scent and flavor of each strain. A proper cure also stabilizes and refines the cannabinoid content.
For example, the non-psychoactive form, THCA, continues its slow conversion into the psychoactive THC, helping the final product reach its full potential potency. The goal is to maintain a balance where undesirable compounds break down slowly while terpenes and cannabinoids are protected. If the process is too fast or too warm, volatile terpenes will evaporate, and cannabinoids may degrade into less desirable forms.
Essential Pre-Curing Step: Proper Drying
Before curing, the flower must be dried slowly and evenly to the correct moisture level. The drying environment should be kept cool and dark to minimize the loss of sensitive terpenes and cannabinoids. Optimal conditions involve maintaining a temperature between 60 and 70 degrees Fahrenheit (15–21°C) and a relative humidity (RH) between 45 and 55 percent. Consistent air circulation is needed, but fans should not blow directly onto the flower, which can cause the outside to dry too quickly.
The drying phase typically takes seven to fourteen days, depending on bud density and environmental conditions. The sign that the material is ready for curing is the “snap test” performed on a small stem connected to a bud. When bent, this stem should snap cleanly rather than just folding or bending. If the stem is pliable, the flower requires more drying time.
Successful drying means the flower has reached an internal moisture content of approximately 10 to 12 percent. This specific moisture level is the boundary between safe storage and mold risk. It is also necessary for the slow moisture exchange required during the final cure.
Step-by-Step Guide to Curing
Once the flower is sufficiently dry, the curing process begins by placing the material into airtight containers. Glass mason jars are the most common option, but food-grade plastic bins or buckets can be used for larger quantities. The containers should be filled loosely, leaving a small air pocket at the top, and never packed tightly, as this prevents proper air circulation.
The first 24 hours are critical for revealing the flower’s true moisture level. Moisture trapped deep inside the buds equalizes with the air, raising the relative humidity (RH). Growers should use a small digital hygrometer inside one of the jars to monitor this internal humidity, which should ideally settle between 58 and 62 percent.
The essential daily step is called “burping,” which involves opening the container briefly to exchange moist, stale air with fresh air. During the first week, burping should be done once or twice a day for a few minutes. This action releases excess moisture and gases produced by the breakdown of plant matter, preventing mold growth.
If the hygrometer reads above 65 percent RH, the flower is too wet and must be removed and placed back into the drying environment for a few hours. If the reading is below 55 percent RH, the flower is too dry, and a small humidity pack designed for cannabis storage can be used to stabilize the environment. After the first week, the burping frequency can be reduced to once every few days. The minimum time for an effective cure is two to four weeks, but extending the cure often results in a more refined flavor and smoother experience.