How To Properly Sieve Bubble Hash for Air Drying


Todde Philips

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

Sieving bubble hash refers to the process of breaking down freshly-made ice water hash using a stainless steel kitchen sieve in preparation for air drying. Sieving is a simple and effective way to grind wet bubble hash into tiny pieces that can release moisture quickly and thoroughly while air drying. Evaporation of moisture is more efficient from small grains of bubble hash than it is from a large patty of hash, which has a tendency to trap moisture within the center of the globby mass.  

Why Dry Bubble Hash?

Wet hash that’s not properly prepared for air drying has a good chance of inviting mold growth, which can be ruinous to your bubble hash by the time you notice it. This is the reason that solventless extractors go to great lengths to properly dry their bubble hash. When prepped correctly and dried in the right environment, bubble hash will be less vulnerable to mold growth. 

Proper drying techniques bring out the best qualities of the hash, preserving terpene content and keeping oxidation to down to livable levels. Once bubble hash is thoroughly dried, it’s ready for pressing rosin, aging, or smoking




Other Ways To Dry Bubble Hash

But sieving and air drying is not the only way to dry wet hash after extraction. Microplaning is another approach that extractors use to prep bubble hash for air drying. This technique uses a tool with hundreds of micro blades to slice the hash apart into minuscule pieces.  

Read more in What Is the Difference Between Microplaning and Sieving for Air Drying Bubble Hash?

Freeze drying bubble hash is the best way to dry bubble hash, although freeze dryers are relatively costly pieces of equipment that don’t fit with more restrictive budgets. However, among extractors who can justify the cost, there are virtually zero regrets in the decision to freeze dry rather than air dry. The end result is consistently far better with freeze drying than air drying. Freeze drying preserves more terpenes, drastically minimizes oxidation, and finishes in about 24 hours. 

But that’s not to say that sieving and air drying can’t deliver premium results. Quite the opposite. Sieving and air drying bubble hash is still a highly effective way to dry high-quality hash. 

Equipment Needed for Sieving


Sieving wet bubble hash doesn’t require much equipment. You might already have everything you need at home. Here’s the list of things you’ll need:

  1. Stainless steel kitchen sieves *ideally one smaller sieve that fits easily into a larger one
  2. Wet bubble hash
  3. Freezer
  4. Parchment paper
  5. Thick piece of cardboard
  6. Paper towels or micro fiber towels
  7. Sheet of 15 or 25-micron screen
  8. Stainless steel spoon
  9. Gloves


How To Sieve Wet Bubble Hash 

The following is an overview of the process of sieving wet bubble hash in preparation for air drying. Some cultivars are more difficult to sieve than others, but this approach works well for most batches of wet bubble hash. As with many things in solventless extraction, you will develop a feel for it with practice.


1. Prep the Hash

Right after extraction, scoop the hash from the bubble wash bags with a cold stainless steel spoon and drop it directly on top of a 15 or 25 micron screen. Screens with the 15 or 25 micron pore size are ideal for preventing trichomes from slipping through, while still allowing moisture to escape. 

Place several layers of paper towels or a micro fiber towel underneath the screen. These absorbent materials act as a desiccant, actively pulling moisture from the hash. 

Carefully move the wet hash in the into the freezer. 

2. Freeze the spoon and sieves

Place the spoon and sieves in the freezer with the hash. Hash remains in a more workable form when it’s cold, so your tools should remain as cold as possible anytime they come in contact with the hash. 

3. Set up the cardboard and parchment paper 

Cut out a thick piece of cardboard to act as a tray, with enough surface area to hold the hash spread out in a thin layer. You can cut out multiple rectangular pieces of cardboard as needed. 

Then, cut sections of parchment paper to cover the cardboard trays. Keep the silicone side of the parchment paper facing up. 

4. Remove the hash from the freezer

The wet hash should remain in the freezer for the minimum amount of time required to render it into a workable condition. Hash that comes right out of the bubble wash bags following extraction is completely saturated and unmanageable. Placing it in the freezer with a desiccant underneath allows the hash to reach a state where you can handle it and coax it through a sieve. 

The frigid temperatures help to harden up the hash and provide some structure to the mass of trichomes. 

The amount of time the wet hash needs in the freezer depends on the level of saturation of the hash, effectiveness of your desiccant, and the specific cultivar you’re working with. Sometimes hash is ready to sieve after just an hour or so, when the outside of the hash develops a somewhat crusty layer that hold it all together. Other times, the hash may require, more time, until the whole mass is almost solid. Ideally, it’s best to remove the bubble hash before it’s completely frozen throughout. 

5. Press / scrape the hash through the sieve

Once the bubble hash is a bit less saturated with water and in a solid enough form to manage, it’s time to work it through the sieve. Grab a chunk of the hash and scrape it back and forth across the inside of the sieve, over the parchment paper and cardboard you set up earlier. Trichomes should come raining down through the sieve and onto the parchment paper. 

Be careful not to scrape the hash back and forth too rapidly, as this will create heat buildup that makes the hash harder to work with. Remember, keep everything as cold as possible. You can even work inside of a freezer by keeping the door open and reaching inside the freezer for this process. 

Rather than using your hands to coerce the chunks of hash through the sieve, you can use a cold stainless steel spoon to press the hash through the screen. 

Another trick is to use a smaller sieve to rub the hash through the larger sieve. Either way the principle is the same: to coax the hash to pass through the sieve and onto the parchment paper, where it lands in tiny grains. The idea is to break down the wet hash into small pieces so the moisture can effectively evaporate. 

6. Spread into a thin layer across the parchment paper

As the hash rains down through the sieve, move the sieve over the entire surface area of the parchment-lined cardboard so that a very thin layer of hash is created. A thick layer of hash defeats the purpose, as moisture will get trapped within the bubble hash. 

After all the hash has been sieved, you can use the cold spoon to spread out the layer as thinly as possible. 




Creating The Right Environment for Air Drying

Controlling the temperature and humidity of the hash-drying environment is key to ensuring your hard work will pay off. The idea is to create an environment where the moisture can sufficiently evaporate from the bubble hash in a slow and even way. 

While air circulation and getting fresh air into the drying room are important factors to consider, direct air blowing onto the hash is never a good option. Maintain movement of the air inside the drying space, but also prevent air from blowing directly onto the hash. 

The room should be clean and dust-free. Keep the lights off while the hash is drying. 

For air drying bubble hash, the ideal environment is 35% relative humidity at 55 degrees Fahrenheit. 

If you don’t want to dedicate an entire room for a drying environment, a wine cooler can be a good alternative. The same rules for controlling temperature and humidity apply. 

Read more in How To Use a Wine Cooler To Dry Bubble Hash.

If sieving is proving too difficult, the cultivar you’re working with may not lend itself to successful sieving. In this case, try microplaning instead. 

Read more about microplaning in What Is the Difference Between Microplaning and Sieving for Air Drying Bubble Hash?


Sieving bubble hash is a simple, time-tested way to prepare fresh bubble hash for air drying. Once you do it a few times, you quickly get the hang of the process. After sieving, a climate-controlled cold room can be set up at home, providing the ideal environment for the hash to dry in the open air. If a dedicated room isn’t feasible for you, a wine cooler can be a good alternative.

While freeze dryers may be the ultimate method of drying bubble hash, these specialty, high-end pieces of equipment aren’t a good fit for every extraction lab (or budget). Sieving fresh bubble hash allows extractors with any budget to get premium results with air drying. 

To learn more, check out these articles about drying hash:

Best Ways To Dry Bubble Hash
Top 5 Hash Bubble Hash Drying Tips
How Long Should You Dry Bubble Hash?

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 a sieve made of?
Most sieves are made of stainless steel, which is great for sieving bubble hash for air drying.

What type of sieves should I buy for drying bubble hash?
Common kitchen sieves made of stainless steel are best for sieving bubble hash. Sieves with slightly larger gaps in the stainless steel mesh are generally better than the very fine mesh, with super tiny holes. 

How do you sieve wet bubble hash for air drying?
Chill the wet hash in the freezer then rub it back and forth over a kitchen sieve, breaking apart the hash into tiny pieces that fall through the stainless steel mesh. Spread the wet grains of hash in a thin layer over parchment paper on top of a thick piece of cardboard. 

Do you have to sieve wet bubble hash for a freeze dryer?
No, sieving wet bubble hash is a preparation for air drying the hash only. Freeze dryers can efficiently dry bubble hash even if it’s left in a thick chunk or glob. 

Is sieving better than microplaning for air drying bubble hash?
Generally, sieving is less damaging to trichomes than microplaning. Microplanes contain rows of hundreds of micro blades that slice through material, capable of cutting through trichome membranes. Ruptured trichomes diminish the quality of the hash. 


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