How To Identify Cannabis Strains for Solventless Bubble Hash Production

Viviane Schute        

Cannabis enthusiast and student of the art of solventless extraction


Identifying strains that are best suited for ice water extraction helps extractors minimize wasted time and resources spent washing material that doesn’t yield desirable results. No matter how perfect the equipment, environment, and process, some cannabis cultivars just don’t dump loads of high quality resin. It all boils down to the trichomes, and that’s where extractors can make the most meaningful assessment of the plant’s potential for solventless bubble hash production. 

Growers who cultivate cannabis for the purpose of hash production look to the resin that it produces. This resin contains high concentrations of the therapeutic compounds that give cannabis its potency, namely cannabinoids and terpenes. It’s not so much about the weight of flowers produced, but the quality and quantity of the trichomes that a plant pushes out. 

Extractors think about trichomes as the “fruits” that coat the epidermal layer of cannabis flowers. But not all trichomes are created equally. The most desirable type of trichomes are capitate stalked, with a bulbous head sitting on top of an elongated stalk. The heads themselves are the most favorable for hash production. Separating these heads from the rest of the plant material is the goal of ice water extraction. 

Read more in our Guide To Trichomes and Solventless Extraction.

Let's look at strain characteristics that are ideal, and not-so-ideal for bubble hash production.

Strain Characteristics That Are Ideal for Bubble Hash Production

Copious Trichome Production
The best cannabis cultivars for hash production produce lots of trichomes. The flowers should be glistening with a solid layer of sparkling resin. Bubble hash is composed of trichome heads, so the more heads we can collect per pound of starting material, the better. These strains are often referred to as “dumpers”, since they dump large amounts of resin. 

Clear Abscission Points 
Abscission points are one of the main features to look for in mature trichomes. An abscission is the natural detachment of parts of a plant, typically dead leaves and ripe fruit. But in this case, we’re looking at the detachment of the trichome head from its stalk, and specifically the point at which the head connects to the stalk. The stalk should taper to a narrow point at which the heads seems to delicately stand. 


These “skinny necks” on trichomes will break readily, allowing the resin head to fall away for collection.     

Fluffy, Airy Buds
Cultivating cannabis for smoking flowers is all about generating the most flower mass as possible, which makes the grow operation efficient and profitable. However, massive weight and high density in flowers isn’t as important for cultivating material for bubble hash production. In fact, fluffier buds can be the ideal for washing hash, since very dense flowers can sometimes be stubborn to break apart and release their valuable trichomes. Even foxtail buds, those flowers that grow tiny stacks of calyxes that taper out into little tails, can be great for washing hash. 

Stable Trichomes
Some strains produce trichomes that readily burst, releasing the oil resin during ice water extraction. This leads to a very greasy mess that is hard to collect. The best strains for hash production are those with trichomes that can contain their resin even through the vigors of washing and sieving. 

Explosive Terpene and Cannabinoid Content
Using potent strains will produce a more desirable hash in flavor, nose, and effect. Cultivars that give off prominent aromas will be in higher demand. And high cannabinoid content will ensure therapeutic effects of the smoke. Without this, the hash will be seen as second-rate.




Strain Characteristics That Are Disadvantageous for Hash Production

Sparse Trichome Production
Cultivating cannabis for solventless production is all about farming trichomes, the true fruits of our labor. Therefore, the best cannabis strains for bubble hash production generate lots of trichomes. Flowers that only produce a modest amount of trichomes won’t yield as much hash.

Unclear Abscission Points
Trichome heads that are well-connected to their stalks with thicker necks won’t release as easily with ice water sieving. Unclear abscission point are an indication that the strain may not be the best candidate for hash production. 

Dense Flowers
Dense flowers may be nice for smoking, but they are harder to break apart when washing hash. It’s often harder to coax trichomes out of dense flowers with ice water sieving than flowers with less density.

Trichomes That Easily Break Open
Some cannabis strains produce trichomes that break open and smear into grease with the lightest touch. If the trichome heads can’t maintain their encapsulated form while washing hash, even with very cold temperatures during the process, that strain probably isn’t great for hash production.

Low Potency
Resin that’s low in cannabinoid and terpene content won’t produce top quality hash. Bubble hash is a direct reflection of the starting material used to create it. 

How To Assess Cannabis Strains for Bubble Hash Production


Getting a close up look at trichomes is the only way to check for certain characteristics like abscission points. A close look at trichomes also helps growers know when to harvest for peak ripeness. A jeweler's loupe is one of the best ways to zoom into the world of trichomes. 

A jeweler's loupe is a small, hand-held magnifying glass used by jewelers to inspect gemstones and other jewelry. They are the perfect size for growers to inspect trichomes and assess their qualities for washing bubble hash. These are great tools that every grower should have around. 


In addition to inspecting individual trichomes, a small test wash of the material is a sure way to find out how it will wash for bubble hash. Sometimes you actually need to use ice water and a set of bubble wash bags to gauge the quality and quantity of loose resin it will yield. Washing an ounce or two will suffice. 

This allows you to assess the material without committing the time and resources into a full scale production using a specific set of genetics. Better to prove its performance before deciding to run specific strains for dedicated hash production. 

A mason jar test can also give you some preliminary insight into how a batch of material will wash for hash. Although the reliability and repeatability of the mason jar test is sometimes questionable, it can still give you some data. Read more about the mason jar test in our article How To Test Material Before Washing Bubble Hash.


Not all cannabis strains are considered good washers. In fact, sourcing cannabis cultivars that make really impressive bubble hash can require some trial and error. Look for strains that produce copious amounts of trichomes with clear abscission points, have fluffy, airy buds, stable trichome heads, and noteworthy potency. Do a small test wash to check it's performance before allocating a substantial section of your garden to any particular strain. 

On the hunt for the perfect cannabis phenotype for bubble hash production? Read more in our article Why Is Pheno-Hunting Important for Pressing Rosin?

The Guide To Trichomes and Solventless Extraction may also be helpful. 

Happy Hashing!

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.


What is an abscission point?
An abscission is the natural detachment of parts of a plant, typically dead leaves and ripe fruit. Abscission points are one of the main features to look for in mature trichomes, specifically the point at which the head connects to the stalk. The stalk should taper to a narrow point at which the heads seems to delicately stand in strains that are ideal for washing bubble hash. 

What qualities make strains good for washing bubble hash?
Copious trichome production, clear abscission points, stable trichome heads that won't easily break open, fluffy and airy buds, and high potency resin are qualities that make cannabis strains good for washing hash. 

What qualities make strains not good for washing bubble hash?
Sparse trichome production, unclear abscission points, unstable trichomes that easily break open, very dense flower, and low potency are qualities that make strains not so good for hash production. 

What is a jeweler's loupe?
A jeweler's loupe is a hand held microscope that's ideal for zooming into cannabis flowers and getting a great visual assessment of the trichomes. 

How can you do a test wash of starting material for bubble hash?
To test wash cannabis for hash production, you can use the mason jar test, or just run a small batch like one or two ounces of starting material. Read more in How To Test Wash Starting Material. 


Leave a comment

Please note, comments must be approved before they are published


Access Denied

You do not have permission to view this page