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How to keep weed fresh

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Contents

  1. Moisture and mold in marijuana
  2. The best temperature to store your cannabis
  3. Light and oxygen change cannabis composition
  4. Extending the shelf life of weed
  5. Frequently asked questions

Over the years, cannabis packaging in legal or medical marijuana regions has become more sophisticated, with features designed to maintain freshness. The packaging on your marijuana products might have a harvest date on them, but flower doesn’t come with an expiration date. So even with producers improving their packaging, you might find yourself wondering: how long does weed stay fresh?

About the two worst ways you can store your bud are on a tray, exposed to oxygen and light, and in a plastic sandwich bag, just like a dealer’s bags that are common on the illicit market. A number of environmental factors affect how well the plant grows, but cannabis storage is also a key component of quality and freshness. Cannabis needs the right balance of conditions to remain fresh.

Cultivators go to great lengths to ensure your flower is packaged with optimal moisture content, usually in opaque packaging to keep light out. You’re probably wondering why you still see transparent and clear containers lining your dispensary’s shelves.

Well, old habits die hard and the practice of seeing and smelling the product on the shelf is still a key component for many people when it comes to deciding what to purchase. Some companies have even started replacing the oxygen in their packaged flowers with nitrogen to help maintain freshness.

For the best possible marijuana experience, you need to know how to keep weed fresh and how to store weed properly. This guide will give you everything you need to know.

Moisture and mold in marijuana

Moisture and water make a big difference when it comes to degrading the shelf life of cannabis.

While no two cultivators dry their flowers in the same way, all cultivators dry their flowers and then put them through a process called curing.

When cannabis is properly cured, it allows the moisture that is trapped inside the bud to slowly dissipate from the flower without changing any of the cannabinoids or losing terpenes. Once the flower has the perfect moisture content, usually between 6% and 9%, it is placed into packaging from which excess oxygen has been removed. When you take it home, it’s important to try to maintain that balance.

Once the flower has the perfect moisture content, it is placed into packaging from which excess oxygen has been removed. When you take it home, it’s important to try to maintain that balance. Photo by: Gina Coleman/Weedmaps

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If you lose too much moisture, it can change the integrity of your flower. Your flower will become brittle and lose essential terpenes that affect potency and taste. On the other hand, with too much moisture or water, the consequences are more serious. So serious, in fact, that the American Society for Testing and Materials (ASTM), which develops technical standards across many industries, published the “Standard Specification for Maintaining Acceptable Water Activity (aw) Range (0.55 to 0.65) for Dry Cannabis Flower” in May 2018.

The ATSM defines water activity as “the (quantitative) capability of the cannabis flower in a sealed container to affect the humidity of the container’s headspace air.” Headspace is the air that surrounds the flower. Water activity measures vapor pressure against pure water. If water activity is 0.55, it is 55 percent of water.

During storage, water activity cannabis should remain within a range of a minimum of 0.55 and a maximum of 0.65. Water activity increases with temperature, which is why light and temperature control go hand-in-hand as best practices for how to keep weed fresh.

The relationship between moisture content and water activity is complicated, and the cannabis industry is still striving to determine the optimal moisture content for packaged flower.

What we know now is that a relative humidity level anywhere above 65% can significantly increase the likelihood that your weed will end up growing mold. According to the American Herbal Products Association, the drying process will dehydrate cannabis until it has a moisture content of less than 15%, and the curing process is where the remaining moisture is slowly removed to retain the volatile oils.

The best temperature to store your cannabis

To extend the shelf life of marijuana, it should be kept in a cool, dark place at or slightly below room temperature. The ideal temperature to store your weed is below 70 degrees Fahrenheit, or 21 degrees Celsius.

High temperatures combined with high moisture activity and relative humidity can lead to mold and mildew. Mold thrives between 32 and 120 degrees Fahrenheit, or 0 to 49 degrees Celsius, and growth is most active between 70 and 90 degrees Fahrenheit, or 21 to 32 degrees Celsius.

High temperatures and arid environments dry out your flower and evaporate sensitive terpenes, which ultimately change the effects and taste of the flower. This is why some cultivators skip drying and make live resin extracts to preserve all the monoterpenes that are lost during the drying process.

Lower temperatures are not as problematic, but they can make it harder for tetrahydrocannabinolic acid (THCA) to decarboxylate into tetrahydrocannabinol (THC). Lower temperatures will reduce the potency of the flowers when they are smoked or could make the trichomes brittle on the plant, causing them to break off when they are removed from the cold environment.

Light and oxygen change cannabis composition

Exposure to light is the biggest culprit when it comes to aging weed. This has been known since at least 1976, when a study published in the journal Pharmacy and Pharmacology explored what happens to the stability of cannabis under various conditions. It concluded that light is the single largest contributor to loss and deterioration of cannabinoids and suggested that “carefully prepared herbal or resin cannabis or extracts are reasonably stable for 1 to 2 years if stored in the dark at room temperature.”

Ultraviolet (UV) light will always degrade your weed, even if you store it safely in glass jars. So, while the clear glass Mason jars you see in the marketplace look nice, they won’t protect your purchase the way an opaque container will. If you really like to look at your marijuana, a brown container will filter out visible ultraviolet light — that’s why brewers use them to bottle beer. Meanwhile, green containers will block out roughly 30 percent of UV rays.

As time goes by, prolonged exposure to light and air will gradually convert THCA into THC. At the same time this is occurring, existing THC is being converted into cannabinol (CBN), a cannabinoid that does not create the intoxicating properties that THC delivers.

Ultraviolet (UV) light will always degrade your weed, even if you store it safely in glass jars. Photo by: Gina Coleman/Weedmaps

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And it’s not just THC that’s affected. Cannabidiolic acid (CBDA) can transform into cannabidiol (CBD) with enough exposure, and THCV will degrade into CBV. During this time, your weed could potentially become less potent.

In addition to playing a role in the conversion of cannabinoids, oxygen can also oxidize essential terpenes and change the overall aroma of the flower into a grassy, haylike smell.

To reduce exposure to oxygen, make sure there aren’t many air pockets in your container. You should always store your weed in an airtight container. Don’t use very large containers to store small quantities of weed, as this leaves too much air inside the container with your herb.

Of course, it is inevitable that some amount of oxygen will get into your sealed package once it is open, but you can limit the amount of time that the jar is opened and the number of times it is opened.

If you store your weed in sealed bags, remove as much air as possible before sealing. Vacuum-sealing weed can be a reliable, long-term storage solution for your stash. If you go this route, be sure you follow these tips to avoid inadvertently damaging your weed:

  • Try to avoid vacuum sealing your marijuana in plastic that contains bisphenol A (BPA). This chemical is a key ingredient in many types of plastic, but it has proven to be harmful to humans. And unfortunately, if you store your weed in plastic containing BPA, some of those dangerous chemicals could leach into your marijuana.
  • Handle your weed delicately. Plastic easily builds up static charges that can pull trichomes off your buds. Trichomes are the cannabinoid- and terpene-rich hairlike glands all over cannabis flowers, so you’ll want to avoid damaging them.

If you plan on storing your vacuum-sealed weed in the freezer, know that freezing will also make your trichomes vulnerable to damage, as they will become brittle.

Extending the shelf life of weed

Knowing how to store weed properly will help you get the most out of your cannabis experience. Ultimately, the key to extending marijuana shelf life is all about limiting exposure to the elements. When it’s time to open your container, pull out your flower and immediately close your package. Don’t let it sit open, and avoid windy or highly ventilated areas.

To maintain the right level of moisture, use a salt-based control sachet to maintain the ideal relative humidity. According to the ASTM standards (D8197-18), “a salt-based control sachet designed to maintain a relative humidity of 0.55 to 0.65 in a sealed container can be used to maintain optimum storage conditions.”

Additionally, you can store your marijuana in a cannabis humidor box, which has been designed to maintain the ideal humidity for marijuana. There are currently several models available on the market.

Whatever you do, be sure you don’t use a cigar humidor to store your weed. Cigar humidors are typically lined with cedar wood. The oils in the wood help enhance the taste of cigars, but those same oils tend to harm cannabis. Similarly, humidors for cigars often use sponges or propylene glycol to create humidity that are ideal for tobacco, but are much too high for cannabis.

In the past, to remedy dry weed, people would add an orange peel to their bags to keep the moisture content, but this greatly increases the likelihood that mold would be introduced. In addition, the water activity of orange peels is unknown and the aroma of the peel could alter the flavor and aroma of your weed.

Nowadays, you can use the same humidity control packs, such as Boveda packs, to reintroduce moisture if it is too dehydrated. This will not reintroduce terpenes that were lost, but it will ensure that you don’t have a harsh smoking experience.

To keep your weed in tip-top shape as long as possible, take careful steps to avoid exposure to light, moisture, oxygen, and extreme temperatures. Photo by: Gina Coleman/Weedmaps

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Like almost everything else, weed doesn’t last forever. Over time, changes to the molecular structure occur with exposure to heat, light, and moisture.

When cannabinoids and terpenes experience very high or very low temperatures, dry up, are exposed to too much moisture, or are left in the presence of light, chemical changes that will degrade the potency of the flower and could alter the taste and mouthfeel may occur.

As terpenes are exposed to environmental changes, they can oxidize or evaporate, creating a change in aroma and effects. And even though all weed degrades over time, the process can be slowed down if you control the temperature, moisture, and the amount of oxygen your flower is exposed to. To keep your weed in tip-top shape as long as possible, keep an eye on the harvest date on the packaging and take careful steps to avoid exposure to light, moisture, oxygen, and extreme temperatures.

Frequently asked questions

What’s the best smell-proof container for weed?

The simplest way to keep your stash smell proof is to make sure it’s stored in a solid airtight container with a sealable top. Sealable glass jars, like a Mason jar, are typically sufficient for storing your stash and keeping in the smell. Some cannabis consumers also use large medicine bottles to keep their stash from stinking up their living space. Online retailers also offer a variety of odor-proof containers designed specifically for weed storage.

Is refrigerating or freezing weed bad?

Refrigerating or freezing weed is definitely preferable to storing it in an area that’s too hot or humid. And though some cannabis consumers report successful long term weed storage through freezing, it’s more than possible to lose freshness and potency to icy temperatures, as trichomes may become brittle and break off more easily. Storing your stash in an opaque, sealed container, in a relatively cool place with minimal sunlight is your best bet for long term storage with minimal degradation.

How to keep weed fresh Copy article link to clipboard. Link copied to clipboard. Contents Moisture and mold in marijuana The best temperature to store your cannabis Light

Learn How to Store Weed So It Lasts!

How Long is My Weed Good For?

When it comes to storing your cannabis, the method you choose makes a huge difference in how long your buds maintain potency and freshness!

But what’s the best way to store weed? Is it vacuum-sealing? Will freezing your buds hurt them in any way?

I’ve tried a few different methods for storing marijuana over the years, and today I want to share what has and hasn’t worked for me!

Properly Stored Weed Looks Full and Sparkly, with at Least a Little Color Left
(Marijuana buds are often green with orange hairs, but sometimes you’ll see other colors like purple or pink)

Improperly Stored Buds Start Turning Brown and Crumbly
(brown or tan weed isn’t necessarily bad, as well-cured cannabis also loses color, but brown and crumbly nugs are often old or weren’t stored in an airtight container. If there’s just random brown patches on otherwise good-looking weed, it could also be a sign of mold!)

Note: Some people actually prefer the effects of wet-cured or very long-cured buds, which tend to be very smooth and offer unique smells, but can also cause buds to take on a mostly brown or tan appearance. In that case, buds should still “stay together” and not be crumbly. Although there are exceptions, usually buds that have turned brown are losing their overall potency and smell as time goes on.
How to Store Cannabis Properly (so it lasts for years!)

If you grow a lot of cannabis at once, you may want to store it so that it lasts until your next harvest! Some growers only harvest once a year (especially outdoor growers) and may need their bud to last until the next fall harvest!

Luckily it’s pretty easy and cheap to store your bud. You don’t need any special equipment besides an air-tight glass jar!

Air-tight glass jars are the best place to store cannabis buds!

Here are the main methods and tools for storing cannabis, with the pros and cons of each:

What’s the Best Method for Cannabis Storage?

1.) Store in Glass Mason Jars in Cool, Dark Place

A cool (60-70°F or 15-21°C) dark place is the most popular way for growers to store buds, and is one of the best and most effective. Quart-sized glass mason jars are found everywhere from grocery stores to home improvement stores. These are often used for cooking (making preserves or marinades for example), but when it comes to storing cannabis they help maintain potency by protecting buds from moisture and air. Glass jars will also completely contain smells while preventing buds from getting crushed during handling. Make sure jars are at least 3/4 full so there’s not as much air being stored in with the cannabis (if you have less bud, use smaller glass jars). Buds stored in airtight glass jars in a cool, dark place will maintain their potency for a year or more.

2.) Freeze Your Buds (Best for Long-Term Storage)

Once buds are completely dry and have been stored for at least 4 weeks, you can freeze them and they will maintain their potency for years. Some growers double-bag buds in Freezer bags and then wrap the bags in foil. This works okay but you can actually store your buds directly in glass mason jars. If you’ve got a lot of bud that needs to be stored for a long time (multiple years), the freezer is the best way to do it!

Note: You should avoid handling frozen buds as the trichomes (glitter) become brittle and can easily break off at freezing temperatures. Always let frozen buds come to room temperature before handling.
3.) Refrigerate Your Buds (Avoid!)

Buds stored in the fridge tend to mold, even in air-tight containers. Either keep buds outside the fridge or put them in the freezer! If you must use the fridge, it’s especially important to make sure buds are completely dry to avoid mold, and keep them in the back in a crisper where the temperature and humidity don’t fluctuate as much. But again, if possible you should avoid using your refrigerator to store buds just in case; a regular cabinet or drawer is usually better!
4.) Plastic Baggies (Avoid!)

Although this is the most common way for non-growers to store cannabis, it’s one of the worst. Buds lose their smell and tend to get dried out and brittle in plastic baggies. The potency degrades quickly, and the lack of protection means that handling the buds tends to crumble them. Plastic baggies should only be used short term, or avoided altogether. If you need to store a small amount of bud, it’s recommended to get a UV-proof glass stash box (will also prevent smells from leaking out!). As a bonus, a small glass container can help buds continue curing.

Don’t use a plastic baggy!

Note: Freezing buds is controversial because it’s easy to lose trichomes when moving frozen buds. You do need to be extremely careful when handling frozen buds as the trichomes (glitter) become brittle and can easily break off at freezing temperatures.

However, if this does happen you can still collect trichomes from the bottom of the container and use them (just like the kief that falls to the bottom of a grinder!); the trichomes do not “vanish” into the ether!

Additionally, you can dramatically reduce this problem by always letting buds come to room temperature before handling them. The fact of the matter is that buds will stay potent for longer in the freezer than if kept at room temperature, so it’s up to you to decide whether the risk is worth the reward. I can tell you that many growers freeze their buds for years to maintain potency, especially outdoor growers who may harvest pounds at a time.

So if you want to use the refrigerator to store buds, don’t risk mold by using the fridge portion – put your buds in the freezer!

Weird fact: Ever notice that the word ‘refrigerator’ doesn’t have the letter ‘d’ in it, but the word ‘fridge’ does? Although ‘fridge’ and ‘frig’ are technically both acceptable spellings, one proposed explanation is that the word was originally spelled ‘frig’ but adding the ‘d’ and ‘e’ became much more popular since the word is pronounced as if it rhymes with ‘ridge’.
Using Glass for Storage

  • Air-tight and smell-proof
  • Doesn’t stop the curing process, and buds may actually continue to cure and gain potency over time
  • Doesn’t affect the natural smell/taste of buds (unlike plastic, metal and some types of wood)
  • Won’t cause trichomes to break off due to static
  • Buds last for 1+ years in a cool, dark place without losing potency

Using the Freezer for Storage

  • If using Freezer Bags (as opposed to glass jars), buds may lose some of their smell/flavor over time due to the plastic, and are easily damaged from handling in their frozen state. However using glass jars in the freezer will help prevent these problems.
  • Always allow buds to warm up to room temperature before handling to prevent trichomes from falling off into the jar
  • Buds that are frozen will maintain their potency for years

Should I Use a Vacuum Sealer?

You can use a vacuum sealer to take all the air out of a container before long-term storage. You can use these with bags, and you can also use these with actual mason jars!

Vacuum sealing is recommended if you plan on storing buds for a long time, and it’s probably a good idea, but in my experience it hasn’t seemed to do much (at least on its own) to slow down the bud degradation process.

When I experimented with vacuum-sealing buds in mason jars, I found that the vacuum-sealed buds didn’t seem to be any different from the same batch of buds stored in non-vacuum sealed jars. After a year of storage, they looked and smoked the same as far as I could tell.

So even if you do vacuum-seal your buds, make sure to follow all the other steps, too!

Boveda Packs – A Helpful Storage (and Curing) Tool!

Sometimes called Humidipaks (their old brand name), the newly renamed Boveda Packs can basically turn any airtight space into a cannabis humidor. The 62% Boveda Packs are specifically designed for storing cannabis and can be placed in a sealed container with your buds to regulate the humidity to the ideal level for marijuana storage.

Boveda packs also help keep buds from getting dried out or brittle (and can re-hydrate buds that are too dry).

Bonus Use: In addition to storage, for those who have trouble getting buds to cure properly, these can be a valuable part of the curing process! Simply place them in your jars a few days into the jar-burping process to help regulate the humidity.
Buds Must Be Dried and Cured Before Storage

If buds are still fresh and green, they need to be cured before being put into long-term storage!

Example of Fresh Bud (May Feel Wet and Usually Appears Very Green and “Plump”) – Never put fresh bud into long-term storage!

Cured Buds (Color Has Darkened Slightly, Buds Feel More Dense and Are Completely Dry) – Always wait for buds to cure for at least 4 weeks before long-term storage!

Whenever Storing Cannabis Long-Term, Make Sure….

  • Buds Have Been Cured for 4+ Weeks – Buds should be cured at least 4 weeks before being put into long-term storage. The potency and smoothness of your buds is greatly improved during the curing process, and you want to make sure they’ve reached peak potency before you put them in storage. Additionally, the curing process is integral to setting a good moisture level for buds about to be stored long term.
  • Buds Are Dry Enough (55-62% Humidity) – Buds should never feel moist and jars should never “sweat” during the curing process. These are signs the buds still contain too much moisture and aren’t ready for storage. Why? Even in a sealed container you can still get mold, and wetness causes potency to deteriorate faster (and buds turn brown and crumbly)! This is really important, because buds being too wet is one of the biggest factors that cause buds to degrade early. If you have a humidity monitor, you are aiming for humidity around 55-62% RH before putting them into storage. This recommended humidity is a little lower than what’s generally recommended for curing, but helps prevent unwanted biological processes during long-term storage.
  • Keep Buds in the Dark – Avoid letting buds be exposed to light because UV rays cause bud potency to diminish
  • No Heat, No Middling Temperatures – Avoid letting buds be exposed to heat or middling temperatures. The temperature should be 60-70°F (15-21°C) or under 32°F (0°C) for the best results. Don’t let buds get cold, then hot, then cold, etc. Don’t store them near electronics that may heat up. Try to maintain a steady temperature until you’re ready to use your buds.
  • Glass is Best, Avoid Plastic or Metal – Although plastic and metal can be used to store buds in the short term, they can start to affect the smell/taste after a while. Therefore they are not recommended for long-term storage. Plastic also tends to be “static-y” which can cause trichomes to fall off the buds and stick to the sides or the bottom of the container. Your best bet is glass, which is completely airtight and nonporous. Quart-sized mason jars are a tried-and-true storage container, which is why they are so popular for cannabis growers.
  • If You Do Go For a Wood Container… avoid cigar humidors as they can impart a cedar taste. Cannabis-made humidors are usually made out of things like teak, bamboo, acacia, mahogany, cherry or walnut wood, as these won’t affect the smell/flavor of your buds. However, wood doesn’t seem to be as effective as glass when it comes to cannabis storage, and buds won’t last as long when compared to being stored in glass.
  • Avoid the Refrigerator – Although refrigerators might seem like a great idea, they don’t maintain a consistent humidity and temperature. These fluctuations increase the chance of mold and other unwanted biological processes. Keep your buds at a cool room temperature or in the freezer.

Now that you know how to store your marijuana properly, you can enjoy every big harvest for years to come!

Beginner Shopping List (What You Need to Start Growing)

Learn the best way to store your weed so it stays potent and smelling great! Proper storage of cannabis can even make buds feel stronger! ]]>