The process of “burping” cannabis is a non-negotiable step in post-harvest preparation that directly influences the final quality of the flower. This technique involves the controlled release of air from sealed curing containers. Burping separates a harsh, grassy product from a smooth, flavorful one by managing moisture and chemical reactions within the buds after they have been initially dried. Understanding this air exchange is fundamental to achieving a perfectly cured product ready for consumption or long-term storage.
Defining the Curing Phase: Setting the Stage for Burping
Burping takes place during the curing phase, which begins after the initial drying process is complete. Drying removes the majority of the plant’s moisture content, reducing it from approximately 75-80% down to a level where the flower is dry to the touch. Once the small stems snap cleanly instead of bending, the buds are ready to be sealed into airtight containers, most often glass jars.
Sealing the flowers marks the beginning of the cure, where the goal is to equalize the remaining moisture. Moisture trapped deep within the buds slowly migrates outward. This controlled migration ensures the flower dries evenly throughout, preventing a brittle exterior and a moist center. Sealing the jar traps the excess moisture and gases that are released, making burping necessary.
The Chemical Necessity of Air Exchange
The primary purpose of burping is to facilitate a necessary chemical refinement within the sealed container. As moisture dissipates, respiration occurs, releasing gases, primarily carbon dioxide (CO2). If this moist, CO2-rich air builds up, it can create an environment that encourages the growth of mold and other undesirable microbes, which thrive in high-humidity, stagnant air.
Introducing fresh oxygen during burping supports the slow, enzymatic breakdown of residual chlorophyll. Chlorophyll is the green pigment responsible for photosynthesis, and its presence gives improperly cured cannabis a harsh, “grassy” or hay-like flavor. As the chlorophyll breaks down, these harsh tastes dissipate, allowing the plant’s true flavor profile, derived from its volatile terpenes, to stabilize and become more pronounced. This controlled air exchange helps preserve the delicate terpenes.
Step-by-Step Guide to Burping
The burping process requires consistency and careful observation, especially during the initial weeks of the cure. For the first week after sealing the jars, open the containers once or twice daily. Each opening should last five to fifteen minutes, allowing trapped, moist air to escape and fresh air to circulate around the buds.
Monitoring the internal environment is best accomplished by placing a small hygrometer inside the jar. The ideal relative humidity (RH) range for the cure is 58% to 62%. If the reading exceeds 65% RH, the jar should be left open for a longer duration to prevent mold from forming.
A physical assessment of the flower is also important. If the buds feel sticky or damp to the touch, or if the jar emits a slightly ammonia-like or overly grassy smell, excess moisture is present, and the burping duration should be extended. Conversely, if the buds feel brittle or crumbly, or if they have lost their aroma, seal the container immediately to prevent over-drying.
Gently shaking the jar during burping helps rotate the flowers and ensures air reaches all surfaces, promoting even moisture distribution. After the first week, the frequency of burping can usually be reduced to once daily, assuming humidity levels remain stable.
Indicators for Ending the Burping Process
Knowing when to transition from active burping to long-term storage relies on specific sensory and environmental indicators. The most objective sign is achieving a stable relative humidity (RH) reading within the container, which should consistently hover between 58% and 62% for several consecutive days. This range indicates the moisture content has stabilized, preserving the flower without risking mold growth.
The change in aroma is the second reliable indicator. The initial unpleasant “hay” or “grassy” smell, caused by residual chlorophyll, should completely dissipate. It should be replaced by the strain’s distinct, complex fragrance, reflecting the mature terpene profile.
As these conditions are met, the burping frequency should be gradually reduced, moving from daily to once every few days, and then eventually to once a week. Once the jar can remain sealed for a full week without the internal RH spiking above 62% or the aroma degrading, the active burping phase is complete. The product is then ready for extended storage, though a continued cure for several months can further refine the flavor and smoothness.