Is vacuum sealing cannabis a good or bad idea? We take a look at some of the best techniques for keeping your weed fresh and potent. Increasing the longevity of your bud is an age-old problem. You want every bowl torched or joint lit to have as fresh a flavor of those terpenes as when you first opened the bag. Click here to find out some of the best ways to keep your weed fresher and more potent for longer! Vacuum purging BHO extracts removes residual butane and propane leaving behind a potent, flavorful, and aromatic oil for medical or recreational users.
Is it Bad Practice to Vacuum Seal Weed? [EXPLAINED!]
It is always a good feeling to ‘find’ cannabis nugs we had completely forgotten about. It saves you a few bucks and a trip to your nearest dispensary. However, is it safe to use weed you discover after a few weeks or months? The answer depends on how the marijuana was stored. If it has been left exposed to heat or sunlight, its THCA will be converted into CBNA, which is then converted to CBN when heated.
As a result, you won’t enjoy the same psychoactive high and may even feel a little dizzy or nauseous. On the other hand, cannabis with a lot of CBN is still potentially useful as a topical. If, on the other hand, your marijuana has been stored in an airtight container in a place shielded from sunlight it could be ‘good’ for up to two years according to most experts.
There are several popular methods of storing cannabis and vacuum sealing is the subject of much controversy. Some users claim it is a fantastic method of keeping bud fresh for a long time, while others suggest it will ruin your weed. What is the truth?
What is Vacuum Sealing?
It is a method of packaging popular in the food industry and involves removing air from the package before you seal it. You can place the items in a plastic film package to remove air from the outside, and shrink film can be used in a pinch. The goal is to remove oxygen from the container to extend the shelf life of products.
It makes perfect sense to vacuum seal marijuana because the process reduces atmospheric oxygen and also prevents the evaporation of volatile compounds. Moreover, vacuum sealing also inhibits the growth of bacteria that would otherwise ruin your marijuana. Once you place your vacuum sealed weed in storage away from sunlight, it should theoretically be usable for years.
There are a variety of machines on the market that do the hard work for you. It is also possible to create your own vacuum sealed product using a Ziploc bag and water. Place the item in the bag and seal it but leave an inch of the seal open. Lower the bag into a tub of water, and be amazed as water pressure pushes the remaining air out of the bag. Seal off the opening before the bag becomes submerged and pull the bag out of the tub.
Is it a Good Idea to Vacuum Seal Cannabis?
On the face of it, there is no reason NOT to vacuum seal cannabis. The main thing is to ensure that the material you use does not contain harmful chemicals. For example, some plastics contain BPA (bisphenol A) which is an industrial chemical that seeps into the material and can imitate the body’s hormones and hurt several bodily functions.
It is better to vacuum seal marijuana than keep it in plastic baggies. These containers do little to prevent air, light, heat, cold or moisture from coming out of the herb. Even sealable baggies are not effective storage options in the long-term. Perhaps the biggest issue with vacuum sealing is the use of plastic. Plastic has a static charge that pulls trichomes from your plant matter onto the material.
It is common for marijuana users to vacuum seal their weed and then freeze it. The process of vacuum sealing eliminates issues with moisture, but you could end up crushing your buds. Freezing can also cause the trichomes to become brittle and break off when handled. Therefore, if you elect to freeze your weed, you have to be incredibly careful when taking it out.
There are usually two types of vacuum seal bags people use. The first option is a food-preserving bag which could allow you to seal up to 1,000 grams of weed depending on the size of the bag. These containers remove all of the air, a huge factor in reducing the risk of mold. The process of compression may reduce the quality of the bud, but at least you keep the aroma and flavor intact. When properly cured, dried, and vacuum sealed, marijuana could last for several years.
The second type of vacuum seal bag is the type that stores clothes. A vacuum cleaner is used to extract the air, and these thick bags have a zip seal that is airtight. You attach the vacuum cleaner to the bag’s nozzle to suck out the air and keep the buds nice and fresh. These bags are the right choice for those who grow marijuana on an industrial scale.
Storing Marijuana – Best Practices
No matter how you store your weed, keep the following factors in mind because they dictate how fresh your cannabis remains.
This process involves heating raw cannabis to activate its cannabinoids. It automatically happens when you smoke a joint or vaporize the herb. If you need to make edibles, you have to place the raw cannabis in the oven to ‘decarb’ it. When your weed is exposed to sunlight, its psychoactive THC degrades into CBN. The result is marijuana that provides a more sedative high.
The temperature your weed is exposed to makes a BIG difference to its quality. It is important to note that common molds and mildew thrive in temperatures of between 77- and 86-degrees Fahrenheit on weed and other organic matter. If you store your cannabis at a temperature higher than 86 degrees, you will dry out the terpenes and cannabinoids.
Terpene molecules vary in size with the smaller ones evaporating at temperatures in the high 60s Fahrenheit. On the other hand, excessively low temperatures could damage your trichomes and slow down the decarboxylating process where THCA is turned into THC. While you could store your marijuana at a temperature of between 32 and 68 degrees, in theory, it is best to keep it between 60 and 65 degrees in practice if at all possible.
This is one of the single most important storage considerations. If the humidity is too high, there is an increased chance of mold growth. If it is too low, the trichomes can break off, and the essential oils dry out. Ideally, your weed will be stored at a relative humidity (RH) of between 59% and 64%, with 62% often classified as the ‘sweet spot.’
The sun’s ultraviolet (UV) rays can damage your buds and interfere with how marijuana affects you. Research has revealed that light exposure is the biggest factor in cannabinoids’ long-term stability rate. The study was admittedly conducted in the 1970s but looked at nine samples of weed left out in different conditions for two years. It found that weed retained its best condition in well-closed containers that were well-filled and left in a dark place at room temperature.
How Should I Store My Marijuana?
In the good old days, it was common to store weed in a ceramic pot or a tin can. Vacuum sealing works just fine as long as the material used does not contain any harmful chemicals. Avoid plastic if possible because it can damage the trichomes. When performed correctly, vacuum sealing prevents airborne damage of your nugs, removes oxygen from the equation and can also stop over-exposure to humidity.
You could vacuum seal individual doses and place them in an airtight glass jar. Perhaps the best method of storing weed IS the glass mason jar. It doesn’t allow oxygen in when tightly sealed, is not impacted by residual humidity and prevents your weed from being damaged due to temperature fluctuations. Glass is a great storage material because it doesn’t secrete any unwanted chemical compounds that could interfere with the aroma and flavor of the weed.
If you can, purchase a dark, tinted, or opaque jar to stop sunlight from causing damage to the cannabis. If you can’t find a glass mason jar for some reason, an airtight titanium container is another solid choice. No matter what option you choose, make sure the container is stored in a cool, dry, dark place which could be a cupboard or a drawer in your home; and keep it out of reach of children!
Final Thoughts on Storing Marijuana
In answer to the title question: It is NOT necessarily bad to vacuum seal weed. It keeps your cannabis fresh for years, but it is important not to use plastic if at all possible. Here is an overview of good and bad storage practices:
Does Vacuum Sealing Cannabis Increase Storage Longevity?
I ncreasing the longevity of your bud is an age-old problem. You want every bowl torched or joint lit to have as fresh a flavor of those terpenes as when you first opened the bag. Even if you can accept a little softening of the taste after a bit, no one wants to smoke old weed. Everyone’s dealt with the headaches, cough, or drowsiness that you’ll experience after the THC molecule has degraded into CBN, and no one is a fan.
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That’s why many flower fans are vacuum sealing their marijuana.
Should You Vacuum Seal Marijuana?
Airtight and out of sight is a pot smoker’s maxim for storing their weed. So it stands to reason that the less air you expose your weed to, the fresher and more potent it will remain. The terpenes won’t dry out, trichomes will stay on the bud, and it won’t burn as hot. Keeping your cannabis from the air will also reduce the humidity, which can cause weed to mold. Store it in a cool place to prevent the cannabinoids and terpenes from drying out further. You’ll want to keep it below 75℉.
So, does this work? Is all you need a good jar and a closet or drawer to keep your weed in good condition for the long haul? The answer is yes. As with most things, the fresher, the better, so be sure to put aside some of your purchase to enjoy immediately. However, if you want to keep your cannabis flower in the best condition possible and store it even longer, vacuum sealing your marijuana is your best bet.
Vacuum Sealing Marijuana
Once your marijuana is vacuum-sealed, some strains can be stored for up to a year without losing a noticeable amount of their potency. Even better, vacuum sealers are relatively cheap online. A quick search on Google or Amazon will give you plenty of options. Everyone has their own opinion on the best vacuum sealer for marijuana, but you can find a home use one for around $50-$75 and a jar sealer attachment is only $20.
If you do decide to go with vacuum sealing your marijuana, jars vs. plastic bags is worth considering. The benefit of plastic bags is their cheapness and ease of storage. If you’re vacuum sealing marijuana in a plastic bag, your nugs will get a little compressed and some small pieces may get crunched off. However, the quality will still be exceptional and it’s not like you’re putting them in a showroom. You’re just going to burn them anyway. As long as you keep them out of the light they’ll still be good.
Vacuum Sealed Marijuana – Bags vs Jars
Plastic bags have some downsides though. If you’re choosing to freeze your weed to keep it an extra-long time, you have to be extra careful when handling the baggie. Frozen trichomes can break off and remain in the bag, instead of going into your body where they belong. Allow your weed to come back up to room temperature before using it.
However, there’s a lot of debate whether or not freezing weed has any real advantages for storage. Many cannabis consumers will say that room temperature works just fine for storage and that between 60-65℉ is the ideal temperature range.
Storing your cannabis in a jars is the preffered method, as it will preserve trichomes better than plastic bags. photo credit
A final issue to consider with vacuum sealing marijuana in plastic bags is that plastic can get a very light static charge. This won’t zap you like a metal door handle when you touch the bag, but it’s still strong enough to pull delicate hairs and trichomes off of your weed. This lowers the potency.
Using a jar adapter to vacuum seal your weed is just as easy as vacuum sealing marijuana in plastic and jars have some big advantages over plastic. They’ll preserve the shape of your nugs, you’ll lose fewer trichomes to crunching and static charge, and they’re more earth-friendly.
With vacuum sealing marijuana in jars, there is the issue of storage. Since glass doesn’t bend or flat pack, you’re stuck needing more storage space.
How to Fluff Up Vacuum Sealed Weed
When you vacuum seal marijuana in plastic, it can get compressed. There’s two schools of thought on this. The first is that vacuum sealed weed that’s compressed is going to smoke exactly the same as fluffy weed once you grind it up, so who cares?
However, there are some that like their weed to look it’s best no matter what final form it takes. To fluff your vacuum sealed weed back up, place your buds in a glass jar with a humidity pack and leave them there for a bit. Once the leaves rehydrate, they’ll naturally fluff back up.
Separate Your Vacuum Sealed Weed Containers
Whether you choose jars or plastic to vacuum seal weed, the final method to long term weed storage is to use a couple of smaller jars or bags rather than one large container. Every time you open the bag or the jar, you lose terpenes and cannabinoids to the air.
By having a couple of smaller containers, you can keep the majority of your vacuum sealed weed from the air and fresh while you work your way through one. Plus it’s easier to portion out your weed if you’re trying to ration it.
The Wrap Up
Of course, you don’t need to vacuum seal your marijuana. Airtight and out of sight works just fine in the short term, as long as it’s not too hot. But it never hurts, especially if you’re regularly buying in bulk. If a small investment is worth having fresher weed longer, vacuum sealing your weed is the way to go.
Frequently Asked Questions
Can you vacuum seal edibles?
Can you vacuum seal edibles?
Yes. Vacuum sealing edibles, especially baked goods, will keep them fresher longer, especially if you freeze them.
Can Mold Grow in a Vacuum Sealed Bag
If there’s enough moisture, warmth, and time, mold can grow on vacuum sealed weed, but it’s unlikely. As long as you correctly vacuum seal your weed, there shouldn’t be enough oxygen or moisture for the mold to grow.
How Do You Vacuum Seal a Mason Jar?
You’ll need to buy or borrow a vacuum seal kit and a special lid. Luckily, these are easy to find online.
Can You Take a Vacuum Sealer Machine on a Plane?
You might get some odd looks, but there’s no regulation against it.
Have you ever vacuum sealed your weed? Share your experiences in the comments below.
How to Vacuum Purge for Cleaner BHO Extracts
Butane hash oil (BHO) of the highest order is vacuum purged for better taste and aroma. As part of an optimized post-processing workflow, a vacuum purge removes all of the excess solvents, in this case, butane and/or propane, to deliver an oil worthy of medicinal or recreational use.
What Is Vacuum Purging?
Vacuum purging, also known as outgassing, cannabis extracts is performed in a vacuum oven that evaporates residual butane and propane from the end BHO products. As a result, BHO processors reap a clean, flavorful, and aromatic oil without the harsh-tasting butane.
Purging systems used to remove butane and/or propane from cannabis and hemp extracts range from homemade contraptions using a large cooking pot as a vacuum chamber to industrial-scale systems capable of handling multiple batches at a time and efficiently heating BHO extracts.
So, how does vacuum purging exactly work? Once your crude oil is extracted, it is placed in a vacuum chamber that reduces the atmospheric pressure, thereby, reducing the boiling points of the butane and propane solvents. In essence, much lower temperatures can be used to purge the butane without degrading any therapeutic compounds.
At a normal sea level elevation, the weight of the atmosphere creates about 29.92” inHg of pressure. This unseen and omnipresent weight affects the boiling point of compounds. When the atmospheric pressure increases, such as at decreased elevation, compounds require more energy for the liquids to boil, which raises their boiling point.
In turn, when the atmospheric pressure goes down, such as when you are at a higher elevation, the boiling point goes down, as well. Using this concept, a vacuum chamber removes the weight of the atmosphere so that the solvent can boil at a lower temp. This is critical to remove solvents without needing to use as much heat.
At sea level, butane has a boiling point of 30.2º F. Propane boils at -43.6º F. While reducing the boiling point of both solvents is possible under a vacuum, you will also be reducing the boiling points of the cannabis compounds. At sea level, THC has a boiling point of 315º F. However, when in a vacuum at -29.9196” Hg, THC boils at 23º F.
Why Is Vacuum Purging Important?
If you are looking to create the highest quality BHO extracts with the least amount of impurities, you are not going to want to skip the vacuum purge. The best way to remove the harsh-tasting and inessential butane solvent from crude oil is through outgassing. Without it, you are left with a tainted oil that probably would not pass state-mandated residual solvent limits. In addition, oxygen is removed from the atmosphere in the chamber which reduces the oxidation of your oil making it fresher and longer-lasting.
What Equipment Do You Need to Vacuum Purge?
Of course, results from a vacuum purge vary by the type of equipment you are using. Differences in equipment may also affect the length of time needed to purge the solvent and temperatures needed to boil off the solvent from the shatter, wax, or whatever else you are making.
A vacuum chamber or a vacuum oven is where all the action happens. Vacuum chambers vary in their heating capabilities, but the best chambers make sure that every part of the oil is evenly heated. A vacuum purge chamber has a stopcock valve that regulates the flow of your gas. Inside the vacuum chamber, you will find a support plate or rack that you can place your BHO on. A vacuum chamber, on a commercial level, features shelving units where an operator can place multiple mats or trays containing a thin film (slab) of the extract.
The indicator on the pressure gauge marks the pressure inside the vacuum chamber. In a vacuum, the pressure should read zero which is when the outgassing can begin. The pressure should be about -29inHg. Most vacuums will measure the atmospheric pressure in inches of mercury. This will be designated in the form inHg or “Hg.
The vacuum pump sucks out the evaporated butane from the chamber. For the highest quality BHO, choose an oil-free pump that can handle the pressures and temperatures used in the vacuum purging process. Choosing oil-sealed pumps can increase the risk of oil leaking onto the shatter or wax and ruining your products.
Now, there are many types of vacuum pumps that produce different vacuum levels. Diaphragm pumps are the best choice for the cannabis extraction industry because they do not use any oil. Plus, they are easy to maintain and are highly resistant to corrosion. Many diaphragm pumps are also quiet and can last for many years. While these pumps can be pricey, they can pay for themselves in the long run.
Rotary vane pumps are an affordable alternative to diaphragm pumps. They produce an excellent vacuum and can be run for long periods of time. They can reach as close to a vacuum level as possible and feature positive displacement characteristics. These pumps may have a lower initial fee, but may require additional maintenance costs because they use oil.
For the best of both worlds, a hybrid pump takes elements of a diaphragm and rotary vane pump to provide a highly corrosion-resistant system. The rotary vane pump technology allows for the creation of the deep vacuum while the diaphragm pump part takes out the moisture before it can degrade the shatter or wax.
Oil-free and hermetically sealed scroll pumps are also a great choice. The motor and bearings are completely separated from the vapor stream and many are approved for cleanroom use.
Finally, diffusion pumps are high-performance pumps that remove the gas molecules from the exhaust with a high-speed vapor jet.
Single-stage and two-stage vacuum pumps differ in price but two-stage pumps feature rotors and vanes. During the two stages, one stage creates the vacuum while the other stage cleans its system. In this case, the two-stage pump provides a deeper vacuum level compared to single-stage pumps. Two-stage pumps are a must if you want quicker outgassing of butane, a cleaner process, and less noise.
A ball valve between the vacuum pump and the chamber can help keep any oil from the pump crankcase from spilling into the chamber. The ball valve allows you to close off the vacuum line when the pump is not in operation. Extraction experts recommend installing an isolation valve, a vacuum gauge, and possibly a ball valve for backfilling from the atmosphere or a nitrogen tank with a filter to reduce contamination in the oil.
A compound pressure gauge is a critical element of the vacuum pump system for making BHO. Invest in a high-grade gauge and calibrate it before starting the process and regularly. Vacuum ovens should never be operated at positive pressure.
The pipe that connects the vacuum pump to the chamber is usually composed of a durable plastic layer on the exterior that has a high-pressure resistance for the purging process. That means it will not get blocked with the suction power created by the pump. Most importantly, make sure your tube is designed to work with your specific vacuum system.
If you are using a silicone mat for your thin layer of resin to place in your vacuum chamber, make sure you are investing in a high-quality silicone. Low-quality silicone features a plasticizer that can absorb into your crude oil. One good way to tell if it has plasticizer in it is to twist and bend the silicone mat. If the twisted area turns a white or hazy color, it may have a lot of plasticizer.
A parchment paper or non-stick sheet can also work in the event you do not have a silicone mat. In addition, a glass sheet or a heat-resistant cover over the boiling liquid can help prevent the bubbling oil from making a mess inside the vacuum oven.
How Long Do You Vacuum Purge BHO?
Vacuum purges range in time depending on the quality of your crude oil and equipment. Vacuum purges can take anywhere from an hour or two to an entire half a day or full day.
What Temperature Should You Purge BHO?
Instead of boiling away your cannabinoids and terpenes at high temps, relying on a vacuum oven system allows the boiling to be performed at a significantly lower temp. Vacuum purging usually happens between 85 degrees and 105 degrees F. Temperatures vary depending on the type of oil.
How Do You Vac Purge?
Vacuum purging is the final stage in creating high-quality and flavorful BHO. Now, there are some main considerations to touch on about the vacuum purging workflow. Everyone’s process is different. Here is a general breakdown of the purging process when making BHO.
Run the Vac
When you have the BHO spread out on a thin layer on a silicone mat or parchment paper, you can place it in the center of the vacuum oven. When the BHO is inside the oven, set the temperature to your desired level and slowly run the pump to a full vac. Once it reaches near a full vacuum, set the oven temperature to 110º F.
Go slowly. As you increase the vacuum, you may start to see the BHO bubbling up and developing a muffin-like top that represents the outgassing of the butane. Over time, the boiling lessens and there are fewer bubbles (this may take a few hours or days).
How long you spend outgassing the butane depends on a few factors including the amount of butane present in the BHO after the water bath and the ambient room temperature. If your room is at a lower temperature, it will be harder to remove the solvent. Many extractors simply look at the BHO to determine its quality. When the bubbles stop and the texture and consistency of the BHO have no change under vacuum pressure, it means the vacuum purging is complete.
Remove All Bubbles
After your desired purging cycle (can be up to 124 hours), you flip the thin layer of shatter on the silicone mat to repeat the process with the exact time and pressure parameters used before. During the second draw, your bubbling will not be as intense, however, there will still be some bubbling. When the boiling begins to subside, you can increase the temperature slightly (if you started at about 105º F, you may increase it to 110º F). Let the BHO sit in the full vac for your desired time (about 6-8 hours).
Repeat as necessary by flipping the slab of BHO and manipulating the temperature and pressure and time based on your desired end product (shatter, live resin, distillate, etc).
When flipping the BHO and to avoid a mess, invest in PTFE sheets over traditional parchment paper with silicone coating. Make sure they are heat resistant, food grade, and non-stick. PTFE sheets are solvent-proof allowing you to purge without absorbing solvent into the sheet. Plus, its non-stick characteristics won’t hold onto any terpenes.
Place a single sheet on top of the silicone mat. Transfer your BHO onto the sheet. When you are ready to flip, add another sheet on top of the BHO while it is still warm.
Place the BHO on a relatively cool surface such as a stone counter, chill block, or cool steel. Allow the cannabis extract to drop in temperature on the bottom. After a couple of minutes, flip over the thin layer of extract quickly and remove the top sheet. The cooling helps it not stick as much compared to a warm extract. If you cannot find this, parchment paper can work just fine. Any non-stick paper can do. Ideally, transparent sheets help you see the product better.
If necessary, consider residual solvent testing a sample of your end product to identify harmful levels of butane or propane solvent and other impurities. Labs use a range of chromatography equipment to identify each cannabis compound and contaminant.
Safety Tips: Outgassing With Care
As with any process that uses flammable hydrocarbons, taking the right safety precautions is critical to crafting high-grade BHO without injuries. Above all, your ventilation systems must be capable of handling the flammable hydrocarbons. Gas detection systems should be in place to make sure any leaks are quickly accounted for.
In addition, you must consider any electrical components used in or near the vacuum purging equipment and the equipment itself. Any out-of-oven purging should be carried out under a fume hood. Everything from non-classified equipment to any other source of ignition can increase the risk of an explosion in the event of a butane leak.
Perfecting the Art of Extraction With Luna Technologies
Purging your BHO is a critical step of the refining process after extraction, but you cannot get good shatter, live resin, or any other extract if you do not start with high-quality biomass. In addition, you need an extraction system that can separate as many cannabinoids and terpenes as possible without as much butane and propane or undesirable compounds.
Luna Technologies’ automated IO Extractor is at the cutting edge of BHO extraction technology. Capable of producing any type of cannabis extract derivative, the IO Extractor is the crux of any BHO processing facility that wants to produce a clean extract with less of the bad stuff.
Optimize your cannabis extraction workflow with an automated closed-loop solution that streamlines your runs, reduces operator error, increases productivity, and extracts better quality concentrates than other methods. A final vacuum purge is the finishing touch to a high-quality BHO made with automated technology.
Cut Labor Costs
Automated controls eliminate weeks or months of apprenticeship training required for manually controlled hydrocarbon systems.
Eliminate Operator Error
Pre-programmed recipe-monitoring system checks pressures and temperatures hundreds of times per second to remove risk of operator error.
Process 18 pounds of dried plant material or 25 pounds of fresh-frozen material per run. Single operator can process 400 pounds of biomass in a single day.
Improve Run Time
50-minute average run time with a 10-minute soak. Run-to-run changeover times of two minutes.