How Long Should You Dry Bubble Hash?

Viviane Schute        

Cannabis enthusiast and student of the art of solventless extraction


Solventless extractors create bubble hash through a process called Ice Water Extraction, in which we mix cannabis flowers together with ice water in order to separate the small appendages called trichomes away from the plant material. These trichomes (and specifically the heads) contain all the therapeutic compounds that cannabis is known for, and they’re the main ingredients of bubble hash. The purest hash is composed almost exclusively of these trichome heads, with only trace amounts of other plant material. 

In order to collect these trichome heads, extractors filter them from an ice water and cannabis mixture using a series of mesh sieves called Bubble Wash Bags. Each sieve in the series contains a different pore size ranging from 220 to 25 microns. 

The sieves which collect the best hash are those which most closely match the size of full, mature trichome heads. These “keeper bags” are often the 90, 75, and 50 micron bags. 

Learn more about Ice Water Extraction in How To Wash Bubble Hash

Why Do We Need to Dry Bubble Hash?

When hash is collected from the bubble wash bags, it’s completely saturated with water. While the water is a useful tool in the hash extraction, it’s counter productive to the actual use and storage of the bubble hash. Wet bubble hash can’t be smoked, pressed into rosin, or properly stored for future use. Especially for long term storage, for example in the form of a Temple Ball, a thorough drying process is critical. 

This is why we need to dry bubble hash after extraction, to remove all potentially damaging, excess moisture and ensure a high quality final product. Drying hash made with Ice Water Extraction is a must. 




What Happens If We Don’t Dry Bubble Hash?

Wet bubble hash isn’t usable. You can’t smoke it or press rosin with it. But not being able to use hash because it’s wet should be the least of the worries. Wet hash can dry, however moldy hash is permanently destroyed and should never be used. 

Wet bubble hash creates the ideal conditions for mold growth, especially within the center of a solid mass of bubble hash. In the center of a chunk of hash moisture is easily trapped and can’t naturally evaporate. Mold can easily take over here within a relatively short time when conditions are right. 

It’s not enough just to check the outside of a big chunk of hash to see if it feels dry. Even if the outside feels dry, the inside could be holding moisture. 

Right after fresh hash is scooped out of the bubble wash bags it’s normally in an watery, loose glob of a hash patty. The hash isn’t very easy to work with in this state, and it’s not going to dry properly if simply left out in the open air in this condition. This is why proper drying techniques, and allowing for ample time for moisture to leave the hash, is so critical to the production of high quality bubble hash. 

What Are The Different Methods of Drying Bubble Hash?

There are various approaches to drying bubble hash. Depending on your volume of output, budget, and overall goals for production, you can choose from one of several techniques for properly drying bubble hash that will deliver high quality results.

Drying can take anywhere from 24 hours to a couple of weeks. The length of time needed to dry bubble hash depends on the method of drying utilized and the environment in which the bubble hash is kept for the drying phase. 

Let’s do a quick review of the main ways to dry bubble hash. 

The easiest and most cost-effective way to dry fresh bubble hash is in the open air within in a carefully-controlled cold room. In order for wet bubble hash to effectively dry in the open air, it needs to be grinded down into tiny pieces. If the hash is left in a big chunk, moisture will be trapped inside and unable to evaporate. 

 There are two common approaches to breaking apart the hash into tiny pieces in preparation for air drying. The first is with a common kitchen microplane, and the second is with a stainless steel sieve. Fresh bubble hash is frozen solid for around 24 hours, then passed over a microplane or through a sieve. This breaks down the hash into a sand-like consistency, allowing the small grains of hash to dry thoroughly in the open air.      


The hash is then spread in a thin layer over a piece of parchment paper, resting on top of a desiccant (usually a thick piece of cardboard). Read more about microplaning and sieving in What Is the Difference Between Microplaning and Sieving? 

Controlling the environment of the room in which the hash is air drying is vital to successful drying. For air drying bubble hash, the ideal environment is 35% relative humidity at 55 degrees Fahrenheit.

A variation of air drying is drying wet bubble hash in a wine cooler, rather than leaving it in the open air. 


 Freeze dryers are a completely automated way to dry bubble hash. They are the most thorough, precise, and efficient way to dry bubble hash. There’s no need to freeze the fresh hash and then break it apart like the air drying method. Rather, the wet hash can be spread out thinly on trays lined with parchment paper and loaded into the machine. 

Freeze dryers use a process called sublimation to remove moisture from the hash. Sublimation is a more efficient way to remove moisture than evaporation, and leads to better terpene preservation as well as decreased oxidation. 

Although freeze dryers are the ideal way to dry bubble hash, their price point isn’t always easy to justify for the home producer or rosin hobbyist. 

Read more about freeze dryers in How Does a Freeze Dryer Work?

How Long Should You Dry Bubble Hash?

The amount of time that bubble hash needs to dry depends on the technique used. If you’re air drying in a cold room, or even inside a wine cooler, then the temperature and humidity settings, as well as the thickness of the hash patties you’re drying, will determine how long the hash needs to thoroughly dry. 

Freeze dryers generally dry bubble hash in about 24 hours. 

Air drying bubble hash in a cold room or wine cooler can take anywhere from one to two weeks. 




How Can You Tell When Bubble Hash Is Dry?

When bubble hash is thoroughly dried, it should feel crumbly and dry to the touch. Some hash will feel greasy, which is a natural characteristic that some strains exhibit. However this is different than moisture. 

Break apart some hash and squeeze a small amount of hash between your thumb and index finger. Roll it around a bit and see if there’s any moisture that squeezes out of the hash. Often, you can see moisture ooze out of wet hash when you squeeze it. If you can’t see any moisture, then feel for it on your fingers. You will be able to sense the difference between wet hash and greasy hash. 

After drying, there should only be trace amounts of moisture left in the hash, less than what you’re able to feel with your fingers. 

When in doubt, it’s okay to dry the hash a bit longer. There is minimal downside to drying out hash a bit longer, and much less potential downside than not drying long enough. 

Bubble hash can become completely dry, unlike cannabis flowers which are better with a higher moisture level. The main concern with overly drying bubble hash is the loss of terpenes and increased oxidation over time. 

This is why the Temple Ball is a great approach to not only storing bubble hash long term, but allowing it to undergo a natural chemical process that makes the product better over time. 


Although it’s easy to put most of your focus on actually extracting trichomes while washing hash, the bubble hash drying process is vital to producing a high quality product. Whether you’re sieving fresh hash and drying in a cold room, using a wine cooler, or enjoying the luxury of a freeze dryer, it’s important to ensure the complete dryness of the concentrate. 

This is especially true if you’re storing the bubble hash for any length of time after extraction. Seal wet bubble hash in a glass jar and in a short amount of time you’ll likely see mold take over. 

Pressing wet bubble hash for rosin is also a bad idea, as it renders a poor yield and compromised quality. Regardless of how you’re using bubble hash, drying after extraction is a must. 

If you can work it into the budge, a freeze dryer will deliver excellent results in a short amount of time. But if not, it’s still possible to create extraordinary, top-shelf bubble hash with an air drying process. 

Thoughts? Let us know by joining our secret Facebook group. Hang out with a community of like-minded solventless heads like yourself. Ask our head extractor questions, share your latest press and learn from hobbyists and experts in the industry.


How long does it take to dry bubble hash?
Depending on the drying technique you’re using, it can take anywhere from 24 hours to over one week to dry bubble hash.

How long does it take to air dry bubble hash?
A freeze dryer can thoroughly dry bubble hash in about 24 hours, but it can take over a week to air dry bubble hash in a cold room or wine cooler. 

How long does it take to dry bubble hash in a freeze dryer?
A freeze dryer can thoroughly dry bubble hash in about 24 hours.

How can you tell when bubble hash is dry enough? 
When bubble hash is thoroughly dried, it should feel crumbly and dry to the touch. Break apart some hash and squeeze a small amount of hash between your thumb and index finger. Roll it around a bit and see if there’s any moisture that squeezes out of the hash. Often, you can see moisture ooze out of wet hash when you squeeze it.

What happens if you don’t dry bubble hash?
Wet bubble hash invites mold growth, which can quickly ruin a batch of hash. Moldy hash should aways be thrown out. 


1 comment


Thanks for the great writeup/instructions! One followup question from a relative newbie to making BH…
In a recent wash of fresh frozen Nutter Budder, the resulting material (about 100g wet) was patted down to a pancake about 1/2" thick and put into the freezer. It was SOOOO sticky I had to leave the work cloth/seive on it until frozen when I could pull it off. I left it in the freezer for a few days, then tried to sieve it, but neither a sieve or a microplane was able to do anything to it…could not break it apart. When it started to warm a bit the stickiness came into play and just gummed everything up. I did squeeze a good ammount of water out using the work cloth immediately following the wash, so I don’t think that was the probem. I finally put it back on the work cloth, let it thaw until malleable again and then rolled it out to about 3/8" thick and moved it between the freezer and the fridge for a couple weeks. Finally the thinned pancake started to crumble with a little presure. I was then able to break it up and sieve it, although by the end the sieve was gumming up pretty bad. It is now in the fridge on cardboard with parchment paper and I am thinking it is about to the dryness you suggest above.
I am curious if you have any thoughts or observations on anything I could or should have done differently.
Thank you for your time to read and respond!

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