Quick answer
Keep cured flower in an airtight glass jar, in the dark, at 60 to 70°F, with relative humidity between 55 and 62 percent. Open the jar for a few minutes each week during the first month, then seal it and leave it alone. A two-way humidity pack and a small hygrometer remove the guesswork. Stored this way, most flower holds quality for six to twelve months.
What you need
- Cured, dry flower, not fresh-cut bud
- Glass jars with airtight lids, sized to the amount you store
- Two-way humidity packs rated 58 or 62 percent
- A small digital hygrometer that fits inside the jar
- A dark cabinet, closet, or opaque storage box
- Labels and a marker for purchase or harvest dates
Steps
- Confirm the flower is cured. Squeeze a bud: it should feel springy, not damp and not crumbly. Moisture trapped at harvest turns into mold in the jar.
- Pick a jar the flower fills about three quarters of the way. Too much air space dries the bud. Too little leaves no room for the humidity pack.
- Drop the hygrometer and one humidity pack into the jar. Use 58 percent for vaporizing and 62 percent for smoking.
- Seal the lid and set the jar in a dark place that holds between 60 and 70°F. Keep it away from the kitchen and bathroom, where heat and steam swing through the day.
- Read the hygrometer after 24 hours. Below 55 percent, add a second humidity pack. Above 65 percent, leave the lid off for 30 minutes and check again.
- Open the jar for two to five minutes once a week during the first month. This vents gases from the cure and swaps the air inside.
- Stop the weekly openings after one month. From that point, open the jar only to take flower out.
- Write the date on the label, plus the strain and the humidity reading when you sealed it.
- Inspect the flower each time you open the jar. Look for fuzz, gray or white patches, or a smell of ammonia or wet hay.
- For storage past a year, move the sealed jar to a freezer at 0°F and leave it there. Thaw it on the counter before you open it.
Humidity and temperature targets
Below 55 percent relative humidity, terpenes evaporate and trichomes turn brittle, so flavor fades and the bud crumbles. Above 65 percent, mold and mildew find a foothold. Temperature matters as much as moisture. A steady 60 to 70°F slows the chemical changes that convert THC to CBN. Every 10°F increase speeds that breakdown. Light is the third factor: ultraviolet rays destroy cannabinoids and terpenes, which is why amber glass or an opaque box beats a clear jar on a shelf.
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How long flower keeps
- 1 to 3 months: peak aroma and flavor
- 4 to 12 months: potency holds, terpene profile fades
- 1 to 2 years: THC shifts toward CBN and effects lean sedating
- Past 2 years: dry, harsh, low flavor
Signs of spoilage
- White or gray fuzz, or powder that spreads when touched
- Ammonia, sour milk, or damp hay smell
- Bud that crumbles to dust under light pressure
- Brown stems with no give
Mistakes that shorten shelf life
- Plastic bags, which pass air and pull trichomes with static
- Jars near a window or on top of a fridge
- A standard refrigerator, where each door opening cycles temperature and humidity
- Jarring flower that is still wet from harvest
- Reusing a humidity pack that has gone stiff and crunchy