How to Store Cannabis Flower

The best way to store cannabis flower is in an airtight container, ideally glass, kept somewhere cool and dark with the humidity held between 55 and 65 percent. Light and air do the most damage, and ASTM International's standard for storing dry flower uses that humidity range to keep buds from turning brittle on one side or growing mold on the other.

Good flower is grown carefully, cured slowly, tested by a lab and then, too often, left on a coffee table in a plastic bag until it turns to dust. Storage is the one part of the whole chain that is entirely in your hands, and it is not complicated.

Four things age cannabis: light, heat, air and the wrong humidity. Control those and flower ages as slowly as it can.

Why is light the biggest threat to stored flower?

If you only change one habit, change this one. In a 1976 study that stored cannabis in varying conditions for up to two years, exposure to light was the greatest single factor in the loss of cannabinoids, and that was ordinary light, not direct sunlight. A jar sitting on a windowsill is losing quality every single day.

Store flower in the dark. A cupboard, a drawer, a closed box. If you like the look of a clear jar, keep it inside something opaque.

Heat, and whether the fridge helps

Warmth speeds up the chemistry that ages cannabis. In a 2020 lab study of flower stored in the dark for a year, 25°C (77°F) produced the largest changes in cannabinoid levels of the temperatures tested. Room temperature in a cool part of the house is a sound everyday choice, and the 1976 study found that temperatures up to 20°C (68°F) made little difference. Keep flower away from the oven, away from radiators, and away from the top of anything with a motor in it.

What humidity keeps flower smooth?

Aim for 55 to 65 percent relative humidity. ASTM International's standard for storing dry cannabis flower sets a water activity range of 0.55 to 0.65: above it, mold can grow, and below it, flower becomes brittle and breaks in routine handling. New York's lab rules hold flower to a water activity of 0.65 or lower before it can be sold.

Too dry and the trichomes go brittle, the bud crumbles instead of breaking, and the smoke turns scratchy. Too damp and you have created somewhere for mold to grow, which is not a quality problem but a safety one.

Two-way humidity packs are the easy fix. The ASTM standard notes that salt-based humidity control packs designed to hold 55 to 65 percent relative humidity in a sealed container can keep flower in that range. Match the pack size to the container, and replace it when it goes stiff.

Air, and why the bag is not enough

Oxygen drives the slow chemistry that ages cannabis. The 1976 study found that air oxidation caused significant cannabinoid losses, and that air, not light, is what turns THC into cannabinol, or CBN, over time. The exit bag your flower came home in is fine for the trip, but a bag is not airtight storage.

Glass with a gasket seal is the standard answer, and the reason is simple. It does not let air through, it does not hold smell between uses, and you can wash it.

Match the jar to the amount. A small quantity rattling around a large jar sits in a lot of air, so use a smaller container as you work through it.

Before you move flower out of its package, know what you are giving up. The New York Office of Cannabis Management (OCM) advises keeping cannabis in its original packaging, which is child resistant and carries the warnings and key details. If you decant, keep the label with the jar, keep the jar in a locked box, and ask about the lockable, child-resistant storage containers New York requires dispensaries to offer.

The small habits that add up

Do not overhandle it. The resin glands on the bud hold what you are paying for, and the 1976 study found losses could be reduced by taking care not to damage those glands. Use a tool rather than fingers, and break up only what you are about to use.

Grind at the last minute. Ground flower exposes far more surface to air, and the 2020 study found whole flower was generally less prone to oxidation than ground flower.

Keep strains separate. Put two in a jar and their aromas start to mix. Separate containers keep each profile intact.

Label the date. Your nose will tell you eventually, but a date on the lid tells you sooner.

Store it the way New York expects. At home, OCM's advice is to keep cannabis locked, out of sight, and out of reach of children and pets. In a car, cannabis should be securely stored in a closed container: New York allows no open containers of cannabis in a vehicle, and neither the driver nor passengers can open the packaging.

What does old flower look like?

Flower stored badly goes dry, pale and dusty, and the aroma flattens into something grassy. The smoke gets harsh because you are burning brittle plant matter rather than a well-cured bud.

Chemically, a few things are happening at once. Terpenes fade fastest: in the 2020 study, average terpene levels fell by more than half within four months at every temperature tested. THC slowly oxidizes into CBN, which researchers use as a marker of aging cannabis. That is why old flower is not simply weaker; its chemistry has changed.

Dry, dull flower is a quality problem. Visible mold, a musty smell, or flower that was stored damp is a safety problem. When in doubt, do not smoke it.

Where to start

Check the dates on what you bring home. New York labels must show an expiration date for the unopened product, and OCM's advice is to look at the use-by date once a package has been opened, because cannabis changes when it is exposed to air. Every product also carries a QR code to its lab results, and our guide to reading a Certificate of Analysis explains how to use it.

Then keep it sealed, dark, cool and locked, with a humidity pack if you decant into glass. That is the whole system, and it is worth more to your enjoyment than almost any other decision you make after you leave the store.

The accessories shelf at both the Fishkill and New Paltz stores carries jars, grinders and humidity packs, and the flower menu shows what is in stock. If you want to talk through what suits how much you actually keep on hand, Ask Our Team. New to all of this? Our guide to your first dispensary visit covers what to expect before you arrive.