How To Test Starting Material Before Washing Bubble Hash


Todde Philips   

🇺🇸 Retired veteran, father, rock-climbing expert & rosin connoisseur

Not all cannabis cultivars make good candidates for hash production. Strains that produce lots of terpenes and high levels of THC don’t always have the characteristics to make great starter material for ice water extraction. While the scent and appearance of cannabis flowers may be indicators of potential hash production, even the dankest buds with the best bag appeal don’t necessarily dump loads of trichomes during ice water extraction. 

The flowers we want for ice water extraction produce high concentrations of both cannabinoids and terpenes within an abundance of terpenes covering the buds. These trichomes are composed of a stalk and a head, and it’s the heads that make the finest hash. 

Good starter material will allow those heads to break off, and they’ll have a strong enough waxy encasement to withstand the agitation of the ice water extraction and maintain their form. Cultivars with trichome heads that burst and release oils while washing are not ideal for bubble hash.  

So what if you’re working with a new cultivar, one that you haven’t washed before? There’s only one way to find out for sure if your starter material will easily release copious amounts of trichome heads during extraction, and that’s with a small test run. 


Don’t Experiment with a Full Run

Rather than experiment with a full batch of starter material and risk committing quality flowers to a process that won’t yield efficiently, you can sacrifice a few grams of either fresh frozen or dried cannabis to give you a good indication. 


There’s a method of washing hash on a micro scale that doesn’t require bubble bags, a freezer, sieve, or other standard hash washing equipment. It allows you to get a glimpse at a strains trichome-dumping potential without the hassle of a full run, using just cold water and a mason jar. 

Mason Jar Test

Shaking a few grams of flower in a sealed mason jar with cold water lets you get a great visual of the amount of trichomes released. Using this test is a great indicator of how the cultivar will perform in a full ice water extraction process. 

Start with a few grams (up to an ounce) of cannabis flowers, broken down into the size you’d use for a standard wash. No need to grind the flowers, just use smaller pieces rather than full colas. 

All you’ll need is a 32oz mason jar and some cold water. 



1. Place the starter material in the bottom of the mason jar

2. Fill with ice cold water and a small amount of ice (the ice is optional but will help to mimic the actual ice water extraction environment)

3. Leave a couple inches of space at the top of the jar, so the water doesn’t come all the way up to the lip

4. Replace the lid and fully seal the mason jar


5. Vigorously shake the jar and plant material for about 10 minutes

6. Let the jar sit for 30 minutes, giving the trichomes a chance to settle at the bottom of the jar

7. You’ll have a layer of floating cannabis at the top, and a nice layer of trichomes at the bottom of the jar

8. Use a flashlight to see into the jar, giving you a better sense of the amount of trichomes released 

Assessing Amount of Trichomes

There’s no exact measurement for the amount of trichomes you should be looking for, it’s all relative. When a strain really dumps trichomes, you’ll be able to tell. When the cannabis either doesn’t have a lot of capitate-stalked trichomes, or it doesn’t effectively release them with an ice water wash, there won’t be a worthy amount of trichomes at the bottom of the jar. 

Once you get a visual of the amount of trichomes settled at the bottom of the jar, you can often make the decision to either pass on that cultivar or commit to a full run. It’s not necessary to collect the hash, but it is an option. 

You can filter out the plant material using a screen, then pour the remaining water through a bubble bag. For a quick check, a coffee filter can replace a bubble bag. Collect the trichomes from the filter and inspect for quality and quantity. You can even dry the tiny sample of hash if you prefer, and see how it smokes. 


When you’re unfamiliar with the way a cultivar washes, try the mason jar test to give you a quick preview of its potential. There’s no need to commit a large portion of a harvest to a process when you’re not confident in a worthwhile outcome. Thanks to the Mason Jar Test Wash, you can work with a cultivar on a micro level to help you decide if ice water extraction is the best use for the material. 


Why should you test wash material?
If you're not sure how a cultivar will yield for ice water extraction, test washing allows you to see the amount of trichomes it will release while sacrificing only a small amount of material, rather than testing with a full run. 

How can you tell if your material will be good for bubble hash production?
If trichomes leave a thick coat the bottom of your mason jar after a test run then that material is good for ice water extraction.

How do you test wash cannabis material?
Place about 7 grams of cannabis in a mason jar with ice cold water and swirl it around vigorously. After a couple mins stop mixing, let the material settle, and assess the amount of trichomes that settle to the bottom of the jar. 

What if the material doesn't dump a lot of trichomes during a test wash?
If the material doesn't release copious amounts of trichomes during a mason jar test wash, it's not going to yield well for bubble hash. It's not worth your time for a full run. 

How often should you test wash material?
You only need to test wash a certain batch of material one time in order to see how it yields for ice water extraction. 


1 comment

Kalani Martin

Hi, I’m working on finding some ideal washing cultivars and have started doing this jar test. Can you please send me some examples of a settled jar that shows what a positive test for washing looks like? An example of a strain that really dumps would be great! Thanks!

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