At some point in our cannabis consumption, we’ve all asked ourselves, “How long is my weed good for?” Maybe you’ve found a few nugs tucked in your winter jacket from last year’s ski trip, or when harvesting a medical crop you may need a way to safely store the excess buds until you’re ready to consume the fruits of your labor.

Like a fine wine cellar or whiskey barrel, properly dried and cured cannabis is best when kept in a cool, dark place. While there is no steadfast expiration date for cannabis, if you store it well it should last about six months to one year before losing considerable potency and flavor.

However, before you spark up that old weed, there are a few key elements to consider when storing cannabis for any extended period.

What’s the best way to store weed?

Ideal temperatures for storing cannabis

Mildew and other molds on cannabis and other organic matter thrive in temperatures between 77° and 86° F, so basic precautions of keeping your cannabis in a cool, dark place will go a long way. Excessive heat can dry out the cannabinoids and terpenes that have taken months to develop. When these essential oils get too dry along with plant material, it can result in a hot, harsh smoke.

Lower temperatures also slow the process of decarboxylation of cannabinoids, the process in which THCA converts into the intoxicating cannabinoid THC. THC eventually degrades into CBN, a cannabinoid with different effects and properties. Additionally, warm air holds more moisture than cold air, which brings us to the next consideration.

Humidity factors for cannabis storage

Humidity control is paramount to keeping mildew and other mold contaminants away from your cannabis. Keeping your cannabis stored in a controlled environment with the proper relative humidity (RH) ranges can be a bit of a balancing act, but the general consensus is to keep cannabis between 59% and 63% RH when stored to maintain and enhance color, consistency, aroma, and flavor.

Keeping your RH below 65% reduces the chances for mold to occur. However, if your RH drops too low, you risk your trichomes becoming brittle and drying out the essential oils.

Light settings for storing cannabis

Harmful UV rays break down many organic and synthetic materials. Similar to the way your grass turns brown at the end of a long sunny summer, or how a car’s paint begins to fade when it is not garaged, UV rays will degrade your cannabis over time.

A study conducted at the University of London in the 1970s concluded that light was the single biggest factor in the degradation of cannabinoids. The same study concluded that cannabinoids maintain stability for up to two years when stored under the proper conditions, though it can remain effective and safe to consume for much longer as the essential oils slowly break down over time. Storing your cannabis out of direct light will also help you control the temperature.

Air control for cannabis storage

Double-check jar tightness to ensure every terpene is conserved.

While cannabis needs oxygen during growing and curing, storing your cannabis in a container such as a Mason jar with just the right amount of air is crucial to keeping it fresh and true to its original form. Having too little air can greatly affect the relative humidity, especially if the buds are not completely dried before storage.

Too much air, on the other hand, will speed up the degradation process as the cannabinoids and other organic matter are exposed to oxygen. There are a variety of hand and electric vacuum pump attachments available for canning jars that will help you minimize oxygen exposure.

How to store your weed

Do – store out of direct sunlight in a cool, dry place

Do – store in containers with a neutral charge, like glass Mason jars

Do – use hygrometers or products like Boveda to monitor and control RH levels

Do – vacuum seal jars and containers to minimize oxygen exposure

Do – separate your strains to maintain their individual flavor profiles. Label them with a date using a Sharpie. It sucks when you mix up strains.

Do – look for the many exciting new ways to store your cannabis. The cannabis industry is growing every day, with new products and companies like Cannador and The Bureau designing solutions for all of your cannabis storage needs.

Do — not stress about storing weed. The best way to get the most out of your herb is to smoke it in a timely fashion!

How not to store your weed

Don’t – store in the refrigerator. The fluctuations in humidity and temperature can actually increase your chance of mold and mildew. If you do refrigerate, vacuum-seal completely. Cold buds will scavenge water from the air, ruining the flavor. Allow container enough time to return to room temperature before re-opening.

Don’t – store in the freezer. Freezing temperatures cause the fragile trichomes to become brittle and break off like little icicles when handled. If you do freeze, vacuum-seal completely and keep frozen. Since a frozen bud scavenges water from the air, ruining the flavor, allow frozen container and buds enough time to return to room temperature before re-opening.

Don’t – store in cheap plastic bags or containers. Plastic often has a static charge that can attract precious trichomes. If you must use a plastic bag, only use it for short-term storage of small quantities of cannabis. Or use a higher-quality bag like a Smelly Proof bag.

Don’t – store above or around electronics or appliances that give off heat. Heat rises—instead, store your cannabis in a low cupboard, shelf, or in the basement of your house, much like a wine cellar.

Don’t – use a tobacco humidor. Most use cedar wood, which has oils that transfer and can influence the flavors of your cannabis. They also tend to employ sponges that use propylene glycol to regulate humidity and can oversaturate your cannabis.

Don’t – store grinders, pipes, or other paraphernalia with your cannabis. The ash and resin from burnt cannabis tends to linger and will stink up any storage container. Also, it is simply good etiquette to keep your supplies separate and clean.

Other factors for storing your marijuana

Products infused with cannabis, such as edibles and other perishable creations, will have different storage guidelines. Use by expiration date.  Keep locked in a container to avoid accidental cannabinoid exposures. Refrigerate as directed.

Alcohol tinctures and other cannabis concentrates also degrade based on heat, light, humidity, and time. Keep extracts sealed tight in their containers in a cold, dark, dry place. While flower shelf-life is usually measured in a year or less—extracts and tinctures can be fridge-stable for years.