What ruins stored weed
Four things decide how well weed keeps: humidity, temperature, airflow and light. Aim for a relative humidity of 59% to 63%, the range cannabis consumers have traditionally been told to stay within (Leafly), a temperature of 19°C to 21°C and always below 25°C, a sealed container that suits the amount, and as little light as possible. Light matters most: in a 1976 study that stored cannabis for up to 2 years, exposure to light was the greatest single factor in cannabinoid loss (Fairbairn and colleagues, Journal of Pharmacy and Pharmacology).
Too much moisture lets mould and bacteria grow, while too little breaks down the trichomes that hold the terpenes and cannabinoids (Leafly). Heat speeds up the damage. In a year-long study published in 2020, the cannabinoids in buds stored at 25°C changed the most, and terpenes, the compounds behind cannabis's smell, dropped quickly under every condition tested, by more than half on average within 4 months (Milay and colleagues, Frontiers in Plant Science). For how fast potency and smell fade, and how to spot mould, see can weed go bad.
Choose the right container
The container does most of the work.
- Glass or stainless steel. Both are non-reactive materials, and glass is also non-porous and doesn't hold a static charge (Weedmaps).
- Not plastic bags. They aren't airtight, and their static charge can pull trichomes away from the buds (Weedmaps).
- Not wood or a cigar humidor. Wood and other porous materials can absorb moisture, and cedar humidors can add oils to the flower. If a humidor is all you have, keep the buds in a glass jar inside it.
- Opaque or UV-blocking, such as amber glass, or kept in a drawer or closet out of the light (Weedmaps).
- Sized to the amount. Weedmaps advises a jar that fits the quantity, since too much empty space means more oxygen, which speeds up degradation. Don't overfill it either: too little air can affect humidity if the flower isn't quite dry.
- The original package. If your cannabis came in child-resistant packaging, leave it there: Health Canada advises keeping cannabis secure in its original child-resistant packaging (Health Canada).
Get the humidity right
A hygrometer measures the humidity inside a container, and a humidity pack dropped into the jar controls or adds moisture to keep it near the 59% to 63% range. Leafly's storage tips also include vacuum-sealing jars to minimize oxygen exposure, and UV-blocking jars help keep light out. Feel is a quick check: crumbly flower is probably too dry, and spongy flower possibly too moist.
Dried-out buds can sometimes be brought back; see how to rehydrate weed. Damp is the bigger risk. White, grey or fuzzy patches can be mould, and Weedmaps says mouldy weed should not be consumed; what to do with mouldy cannabis explains the next steps.
Where to keep it
Pick a cool, dry, dark spot, such as a closed cupboard, drawer or closet, out of direct sunlight and away from anything that heats up; Weedmaps lists windowsills, cars, bathrooms and cabinets near the oven among the places to avoid. Keep buds whole until you need them: in the 2020 study, grinding was one of the least favourable conditions for terpenes, so grind just before use (Milay and colleagues).
Fridge or freezer?
Weedmaps advises against both for dried flower in most cases. A fridge cycles temperature and humidity, and every opening of the door brings moisture swings and a risk of condensation, while freezing makes trichomes brittle, so they break off when the buds are handled.
Lab results add some nuance. In the 2020 study, whole buds kept sealed in the dark at a steady 4°C held their compounds best, while storage colder than minus 20°C was among the worst conditions for terpenes. The difference is stability: a household fridge is not a controlled chamber, and fluctuation is exactly the problem Weedmaps describes, so a cool cupboard is the simpler choice.
Edibles, concentrates and pre-rolls
- Edibles, oils and capsules. Room temperature or the fridge, following the manufacturer's directions, and clearly marked if they go in the fridge. Health Canada says to store edible cannabis separately from regular food and drinks and to label homemade edibles so they are not mistaken for ordinary food.
- Kief and other concentrates. An airtight glass container in a cool, dark, dry place, handled with a clean scoop rather than fingers. More on kief in what is kief.
- Pre-rolls. Health Canada classes pre-rolls as dried cannabis, the same as flower (Health Canada), so the same rules apply: sealed, cool and dark. Many labels also list recommended storage conditions, so check the package.
Store it safely around children and pets
Health Canada's advice: store cannabis locked away and out of sight and reach of children and pets, in a cupboard with a strong childproof lock or latch, or in a lockbox or safe; never leave it unattended where children can get to it; and keep it in its original child-resistant packaging. Edibles need the most care, because accidental poisonings from edible cannabis are a serious risk to children and pets (Health Canada infosheet).
Health Canada reports that many poisoning cases involve children under 12, most of them under 5, and that serious cases can lead to a coma, time on a ventilator and, rarely, death (Health Canada). Signs include vomiting, confusion, unresponsiveness, slurred speech, unsteadiness, drowsiness, slowed breathing and, rarely, seizures.
If you think a child has eaten cannabis, call 1-844-POISON-X (1-800-463-5060 in Quebec), or 9-1-1 if they lose consciousness or have trouble breathing, and say you suspect cannabis. If a pet eats cannabis, the Canadian Veterinary Medical Association advises taking it to a veterinary hospital right away and telling the vet what it ate.
Carrying it and keeping the smell in
The same rules travel with you: a small airtight, opaque container keeps air and light out, and that airtight seal is also what keeps the smell in. In Ontario, adults 19 and older can carry up to 30 g of dried cannabis, or the equivalent, in public (Government of Ontario).
Buying amounts you will use
Since aroma fades within months, buying smaller amounts more often means less flower sitting in a jar. GasDank delivers same day across Toronto and the GTA, usually within 1 to 2 hours, and ships mail order across Canada. Browse flower; the menu carries lab-tested products. Customers must be 19 or older (21 in Quebec), with ID checked at the door.
