Cannabis Storage Secrets for Beginners

Posted on November 1st 2018

People interested in cannabis products want to know how the medicinal components of marijuana change over time from the day of purchase. 

Dry marijuana flowers have a “best before” date ensuring freshness and quality, but it's null and void if the flower isn't stored properly.

The cannabis flower has quite a long shelf life, but after about a year it starts to lose its smell. The THC (tetrahydrocannabinol) doesn’t degrade as quickly, but the subjective quality of it begins to deteriorate.

Terpenes are the aromatic compounds in cannabis, and so smell can be a good indicator of whether the marijuana has degraded because terpenes evaporate over time if not stored properly. Colour is another indicator. After about five years, the plant material may start to turn brown because the chlorophyll evaporates.

THC, the buzzy, euphoric cannabinoid, degrades over time if the flower is not kept in an air-tight container and stored in the dark. It changes into something called CBN, or cannabinol, which has a different psychoactive profile altogether.

How Long Does it Take for Cannabis to Expire?

How long it takes before the properties of cannabis change is unknown, but experts say a matter of months. You would certainly expect to see changes over a year.

As for cannabis oils, they can expire over time and should not be consumed past the expiry date. Fats are a food product that can eventually go rancid. An example is cannabis resin dissolved into something like store-bought MCT (medium chain triglyceride) oil. 

Also worth mentioning is how unnecessary it is to keep dried marijuana in the fridge or freezer. Some people do it to preserve the natural smell of the pot, but the trichomes—crystal-like glands on the flower and leaves that produce the cannabinoids and terpenes—on cannabis are very delicate. When you freeze marijuana, they can fall off rendering the plant less potent.

Health Canada wants citizens to be responsible, by keeping dried marijuana in a cool, dry place and out of reach of children and pets. 

The government-proposed plain packaging of cannabis products will require both a product packaging date and an expiry date, as applicable.

With legalization consumers will know the cannabis potency of the products, and they need to know that potency is lost without proper storage of the product. It may not be dangerous to use the same amount of the plant after the "best before" date—not like chicken or dairy—but changing the amounts in edible recipes, for example, with the argument 'add a bit more because it's old' may lead to a bad experience. For certain, it is a "freshest before" date.

You Don't Need a Humidor for Your Marijuana

Marijuana storage has two primary goals: keeping it out of reach of kids and pets, and keeping it mould-free. Mould isn't just gross, smoking it is seriously dangerous. 

You don't need a weed humidor if you can create the right environment for your bud. Let these weed storage tips be your North Star to tasty, terpy, mould-free bud.


Too hot and you lose terpenes; too cold and all those sugary trichomes become brittle and break off. Plus, mildew and other moulds thrive between 77° and 86° F. Store all bud in a cool place. Aim for 60° F (with humidity set to about 59% and 63% RH) to keep all cannabinoids and essential oils stable. Glass jars—the kind used for jams and pickles—are excellent. Throw in a hygrometer or products like a Boveda pack to monitor and control RH levels to be extra sure.


UV light is damaging to dried cannabis; keeping it out of the sun and some cannabinoids can remain stay stable for up to two years. Splurge on a UV-resistant glass bottle to keep terps tasty and cannabinoids unspoiled.


Exposure to too much air speeds up degradation, and too little allows moisture to hang around growing mould. One item that cannabis connoisseurs love is a hand-held electric vacuum pump to remove air from storage containers; like the pumps that home cooks use in canning sauces and jams. 

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