How to Make Bubble Hash Like a Pro

Hash rosin is my favourite extract, it is a true full spectrum extract and there is a wide catalogue of products you can make from hash rosin. To make hash rosin you first need to know how to make bubble hash (aka Ice Water Hash). You use Ice, Water, Agitation and 25 – 220 micron (μ) filter screens to separate plant matter from trichomes– the small wax-enclosed glandular heads that contain up to 90% of the plants cannabinoids, terpenes and flavonoids. There is no need for non-polar solvents like ethanol or butane, so this is known as a ‘solventless’ extraction method.

Isn’t Water a Solvent?

Ice Water extraction uses no solvents. It is a physical extraction method where ice water is used to transport the trichomes through a series of mesh bags with varying micron levels. The ice water keeps the trichomes from melting and smearing into the mesh, so it is critical that you work in a decently cold environment.

THC/CBD is non-polar, so it does not dissolve in water (as anyone who has tried to clean a bong with water has learned). The water carries trichomes through the mesh, like sand being carried away by a river.

Tools needed:


  • Cannabis (Fresh Frozen, or Dry)
    • I rarely wash less than a QP (112grams) even for test samples
  • ICE (40+ lbs minimum)- Large 1.25″ Draft ICE is best
  • Heavy Duty Parchment Paper

Fresh Frozen Vs Dried Material

You can make ice hash from either fresh frozen or dried cannabis. The input material will have a direct correlation with the output hash. There is no magic here… fire in, fire out. Garbage in, garbage out.

Fresh frozen – lighter bubble hash that is higher in monoterpenes (fruit and gas flavours)

Dried material – darker golden brown/yellow hash. It will be higher in sesquiterpenes (cured flavour profile)

How To Trim Cannabis for Bubble Hash

Fan leaves with no trichomes should be removed as soon as the plant is harvested. Fan leaves with trichomes can be run together, removed & run separately or used for edibles. Sugar leaves should always be left on, removing them can only be accomplished by cutting leaves in half, which will release chlorophyll and colour the hash green

How to Fresh Freeze Cannabis for Ice Hash

If you decide to run fresh frozen material it must be frozen quickly. To do this I use a chest freezers and these woven baskets which allow the plant material to freeze quickly without wilting or chlorophyll bleeding. For small batches I remove all fan leaves at the stem. DO NOT CUT LEAVES IN HALF… only remove leaves at the stem. You don’t want green hash. Leaving fan leaves on entirely is an option too, one that is much better than running trimmed material where cell walls have been ruptured.

Put the cannabis into the freezer as quickly as possible.

The flowers should be bagged up into Large Ziploc Freezer bags within 4-12 hours of being put in the freezer to prevent freezer burn. You can go straight to the freezer bag but I find freezing in open trays or containers helps preserve bud structure and increases quality.

Cold Water Rinse System

When you are collecting hash you will want ice cold water to rinse it with. Tap water is rarely cold enough, and is usually full of chlorine. I use a 20 gallon bin filled with filtered water and ice. A small 1/4 HP pump hooked up to a garden hose provides flow. I use on/off switches so the pump can be powered off when not in use, preventing it from heating up the water bath.

Another options is to use a pressure sprayer that you fill with ice and filtered water. This is obviously a much cheaper option but I prefer the high output of the 1/4 HP pump, especially when cleaning the bags at the end, which should always be done with cold water and NO SOLVENTS (which can damage nylon filter bags and make them more likely to have hash stick to them in the future)

How To Make Bubble Hash

Step 1: Setup for Making Bubble Hash

Setup filter bags inside of your collection tote, matching bag size to tote size. For example I am using 20 gallon bags here in a 20 gallon tote. Setup the bags from smallest to largest. For full spec I will setup as:

45μ > 160μ

Setup your Agitation Vessel as follows:

Hashtek Filter Screen > Draft ICE > Cannabis > Draft ICE > Cannabis > Draft ICE

Add a layer of DRAFT Ice. We recommend the use of this large ice whenever making ice water hash. It tends to last a lot long and can be recovered for use in multiple washes.

Next add the cannabis overtop of the ice.

Add a layer of ice overtop of all the cannabis.

Then add water from the Cold Water Rinse System until the ice is covered. Fresh frozen material should be washed immediately, while dried material should be rehydrated for 15-45min before agitation.

Novices sometimes soak fresh frozen because they are used to doing this with dried material. It is simply not required and can actually increase the chances of getting chlorophyll bleed in your hash.

Step 2: Agitation

Your goal is to separate the trichomes from the plant matter without breaking up too much of the plant matter. This is what Hashtek’s top-down agitation systems are designed to do. If you don’t have a Hashtek agitator you can do it the old school way with a stainless steel paddle.

Agitation cycles are typically 3 – 20 minutes. Note that with fresh frozen you have a much narrower agitation window before you start getting chlorophyll bleed. I usually do quick 10 minute agitation cycles with fresh frozen


Step 3: Filtering

There are usually two main micron ranges I collect:

Option A: 45μ-159μ Full Spectrum: This is my preferred fraction of bubble to use for hash rosin. Captures the full profile, yields the most and only leaves you with three collection bags to wash. Waste is minimized and you only have to collect bubble from one bag, the 45μ.

Option B: 74μ – 119μ Broad Spectrum – If I want to make a really clean vaping hash I’ll throw in a 73μ bag in order to filter out some more of those broken heads that you tend to get in the 45. The 46μ-71μ can be used for edibles, lower grade hashish or even thrown out if you’re in a state that is saturated.

IMO narrowing the fraction any further is typically not necessary for hash rosin since you will be filtering again when you press the bubble into hash rosin. For something as tight as a 90μ-119μ first pull fraction I would just dab it as ice water hash (aka flags).

Step 4: Rinsing

Hash needs to be rinsed and flushed before collection. There are three main reasons for rinsing

  1. Move the hash to one area of the bag for easy collection
  2. Wash through any water soluble impurities or foam that may be temporarily trapped in the bag
  3. Filter through any smaller micron levels that may have gotten caught up in a slurry of hash


Often times, especially when running dry material, the 160μ bag will have a large amount of hash trapped in it. Rinsing thoroughly will help push the smaller micron trichome heads to their appropriate filter level. Use a garden sprayer on the “flat” mode and don’t be shy when rinsing/flushing the hash. I like to hit it pretty hard with the clean water rinse. This is your one chance to clean up the hash so use it wisely. Only rinse with ice cold water.

Step 5: Bubble Hash Collection

Prepare drying trays by lining them with parchment paper. I use a Harvest Right Freeze Dryer to dry my hash. They are expensive but pay for themselves in no time. Air drying techniques like the microplaning tek leave you with a darker, often inferior quality hash (due to oxidation during the drying stage). There is also a much greater risk of microbial growth during air drying vs freeze drying.

The longer you wash, the more green/brown and contaminated your hash will get. Fresh frozen tends to go green while dried material goes towards brown when it is over agitated. How much you want to collect is personal preference. I use the cleanest material for dabbing out of the Peak Pro (after pressing into hash rosin) while subsequent pulls are usually used for hash rosin joints.

Step 6: Drying

Go to Custom Setting on your Harvest Right Freeze Dryer (see here for a comparison of Harvest Right models) and input the following:

Shelf Temp: 45 F
Final Dry: 24:00

The default shelf temp setting of 55F is a bit too hot for hash, especially since the units run a bit warmer than the preset temp. If you ever get hard chunks in your hash (that are not frozen water due to insufficient drying) there is a good chance you baked your hash with too warm of a shelf temp.

Load the trays in the freeze dryer. If the trays are pre-frozen you can lower the freezing cycle down to 30 min. if not pre frozen give it a good 6-10 hr freezing cycle. You want to make sure the material is fully frozen before the vacuum pump kicks on.

Below you can see the difference in appearance between using fresh frozen cannabis and dried input material:

Part 2: How to Make Hash Rosin

See part 2: for a guide on pressing hash rosin. The results between fresh frozen/dried material can be seen below.

Hashtek at The Smoking Jacket

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