Terpene Preservation During Drying and Curing

Quick Answer

Terpenes are volatile aromatic compounds, and they leave the flower fast when the room is warm, dry, or bright. To hold them in place, dry harvested branches at 60 to 68 F and 55 to 62 percent relative humidity for 7 to 14 days with indirect airflow, then cure the trimmed flower in sealed glass jars at 62 to 68 F in the dark. Burp the jars once a day for the first week, then drop to once every two or three days. A slow dry preserves the smell that a fast dry burns away.

Common Mistakes Drying Cannabis: A Buyer's Guide to Properly Cured Flower

Prerequisites

• A drying room or tent that holds near 60 F and 55 to 62 percent relative humidity
• A calibrated hygrometer and thermometer
• Pruning shears, nitrile gloves, and clean trimming trays
• Mason jars with airtight lids
• Mini hygrometers that fit inside the jars
• A dark cabinet or closet for storage

Step-by-Step

1. Irrigate the plants with plain water only during the final week before harvest.
2. Check trichomes with a loupe and cut when most are cloudy with a few amber.
3. Harvest in the early morning while the room is still cool.
4. Cut branches into 12 to 18 inch sections and strip the fan leaves.
5. Hang the branches upside down with 6 to 12 inches of space between stems.
6. Set the room temperature to 60 to 68 F.
7. Hold relative humidity at 55 to 62 percent with a humidifier or dehumidifier.
8. Point an oscillating fan at the wall so air moves without hitting the buds.
9. Keep the space dark for the full drying window.
10. Test a stem each day by bending it until it snaps instead of folding.
11. Trim the flower once the stems snap, which usually happens between day 7 and day 14.
12. Fill jars three quarters full with loose buds and add a mini hygrometer to each one.
13. Open each jar for 10 to 15 minutes daily during the first week of cure.
14. Cut burping to once every two or three days for weeks two through four.
15. Store the sealed jars at 62 to 68 F in a dark cabinet.
16. Dump any jar that reads above 65 percent humidity onto a tray and dry it for 12 hours.

Mistakes That Cost Terpenes

• Drying above 75 F, which pushes monoterpenes like limonene and myrcene into the air
• Rushing the dry in under five days with heat or strong fans
• Aiming a fan straight at hanging branches
• Packing jars tight so moisture and heat build up
• Leaving jars in sunlight or under grow lights
• Bypassing the cure and going straight to storage after the dry

Target a final water activity near 0.60 to 0.65 before long term storage. Flower held in that range resists mold while the terpene profile settles into the cured aroma that buyers expect.

how to dry and cure cannabis properly