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The purpose of drying cannabis flowers after harvest is to prepare those flowers for either smoking or storage. Wet flowers can’t be smoked, and if they’re stored while they contain excessive moisture, they quickly invite mold growth. Drying cannabis flowers allows the chlorophyll inside the plant to degrade, making for a smoother smoke. It also enables cannabinoids like THC to convert from their non-psychoactive and acidic form (THC-A), into its psychoactive form. After cannabis flowers are dry they’re ready for a cure and then longer-term storage in sealed glass jars.
Temperature, humidity, and airflow are the main variables to consider when drying cannabis flowers post harvest. The ideal temperature is around 65 degrees Fahrenheit, humidity around 50%, and airflow that circulates fresh air into the drying space without blowing air currents directly onto the buds themselves. Air that blows directly onto the flowers can cause them to dry too quickly, allowing volatile terpenes to escape in the process.
Under ideal conditions, flowers normally take around 10-14 days to dry.
Read more about the right conditions for drying in What Is the Best Environment for Hang Drying Cannabis Flowers?
There are multiple ways that growers can create the spaces and environments for flowers to dry efficiently and both preserve and enhance their best qualities. These include different kinds of racks, containers, and small spaces that allow growers to control temperature, humidity, and airflow.
So what are some of the best setups for the home grower and hobbyist to manage the drying process? Let’s look at a few ways to properly dry flowers after the harvest.
1. Drying Boxes
Clean cardboard shipping boxes are good for drying cannabis, as long as they are placed in climate controlled rooms. Cardboard is better than plastic, because it allows for moisture transfer and breathability. Grow tents are good places to keep the cardboard boxes, since the air flow and humidity can be controlled.
Keep the tops of the boxes open, to allow for air flow. Also, placing a digital hygrometer inside the boxes is a great way to monitor moisture humidity levels. Hygrometers should be used inside drying boxes, plus with the other approaches listed below.
2. Paper Bags
Similar to drying in cardboard boxes, paper bags make for good breathability. But paper bags have the advantage of being easy to open and close by rolling up the tops of the bags. If you roll up the top of a paper bag to close it, you can increase the humidity inside the bag. This is ideal if the room where you’re keeping the bags is too dry.
3. Self-Contained Spaces
A small closet can be a great place to dry cannabis flowers, because you can control airflow by opening and closing the door. Small fans inside the room, used for airflow but not blowing directly onto the flowers, is a good addition to small spaces. You can also add dehumidifiers and humidifiers as needed to control the environment.
4. Drying Racks for Hanging
Drying racks allow for plants to hang upside down, with ample room between the buds to encourage airflow. Drying racks should be placed inside rooms that have temperature, airflow, and humidity controls. Any type of rack that's strong and stable enough to support the weight of the individual branches will work well. Make sure it's clean as well.
5. Vertical Mesh Drying Rack
Mesh drying racks don’t allow for hanging plants upside down, rather buds are cut from the branches and layered onto surfaces made of mesh. These mesh shelves are stacked vertically with spaces in between each shelf, and the whole rack can hang from a ceiling rafter or other support.
Things to Avoid When Drying Cannabis Flowers
These five approaches are useful for drying cannabis, but they’re not foolproof. In order to dry cannabis for preserving the maximum amount of its therapeutic qualities, while also minimizing the chances of mold growth during the process, growers need to avoid some pitfalls.
1. Don’t stack the buds in thick layers. Stacking in thick layers will compress the flowers at the bottom of the pile. This can potentially damage trichomes. Sometimes, with drying in boxes for example, growers need to stack buds on top of each other to fit everything inside the boxes. Just one single layer is ideal, but not always possible.
Try to keep the thickness of the layer of flowers to the bare minimum, to avoid crushing the trichomes on flowers at the bottom of the pile.
2. Don’t dry in sealed jars or closed containers. This prevents fresh air exchange and trapped air will quickly accumulate moisture and encourage mold growth.
3. Don’t dry the flowers in the same room where you’re actively growing cannabis. The conditions in which living cannabis plants thrive are different than conditions needed for drying. Living plants like higher temperatures and humidity, and drying flowers in these conditions can cause mold growth.
Drying is the first step after harvest to prepare your flowers for storage and consumption, unless you’re immediately freezing a cannabis harvest in order to wash fresh frozen hash. After spending months cultivating the plants, everything can be lost during drying if it’s not done with intention and purpose. Mold is the worst enemy when drying, which can easily ruin an entire crop. And mold can grow quickly in high humidity environments.
There are different ways that you can approach drying, using any of the different setups listed above. However, the temperature, humidity, and airflow requirements are standard throughout.
After the flowers are thoroughly dried, it’s time for curing. Read more about curing in our article How To Cure Cannabis Flowers.
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FREQUENTLY ASKED QUESTIONS
What is the best way to dry cannabis flowers?
There are several ways to dry cannabis, but one of the best ways is to hang branches upside down with the buds still attached to the branches.
Can you use cardboard boxes to dry cannabis flowers?
Yes, it's okay to put flowers in cardboard boxes for drying, just leave the tops open and don't make the layer of flowers too thick (it will crush the flowers at the bottom).
Can you use paper bags to dry cannabis flowers?
Yes, it's okay to put flowers in paper bags for drying, just leave the tops open and don't make the layer of flowers too thick (it will crush the flowers at the bottom).
What is a mesh drying rack?
A mesh drying rack is made of mesh shelves that are stacked vertically with spaces in between each shelf, and the whole rack can hang from a ceiling rafter or other support. Flowers lay flat on the shelves for drying.
Should I blow air on cannabis flowers to make them dry faster?
No, don't blow air directly onto cannabis flowers for drying. This can lead to excessive terpene loss.