When you're making bubble hash, two micron sizes you'll hear about again and again are 73 micron and 90 micron.

Both can collect excellent resin, but is one actually better?

The short answer is: it depends on the starting material.

Trichome heads aren't all the same size. Genetics, maturity, growing conditions, and starting material can all influence where the best resin ends up in your bubble bag set.

That means the 73µ bag might produce the standout fraction in one batch, while the 90µ bag performs better in another.

In this guide, we'll explain the difference between 73 vs. 90 micron bubble hash, what each bag collects, why both are important, and why you shouldn't automatically assume one micron size is always the best.

What Does Micron Mean in Bubble Bags?

A micron, written as µm or µ, is a unit of measurement equal to one-thousandth of a millimeter.

With bubble bags, the micron rating refers to the approximate size of the openings in the filter mesh.

For example:

90µ bag = approximately 90-micron mesh openings

73µ bag = approximately 73-micron mesh openings

As ice water passes through a properly stacked set of bubble bags, different-sized material is separated into different fractions.

This allows you to inspect and collect resin by size instead of putting everything into one pile.

What Does a 90 Micron Bubble Bag Collect?

The 90 micron bag captures material that is retained by its mesh after smaller material passes through.

For some cultivars, this size range can contain a high concentration of mature trichome heads.

That's one reason the 90µ fraction is often closely examined by bubble hash makers.

However, there's an important point:

90 micron does not automatically mean premium quality.

A 90µ bag is a size separator, not a quality guarantee.

The actual material collected depends on what you put into the extraction system.

What Does a 73 Micron Bubble Bag Collect?

The 73 micron bag has smaller mesh openings than the 90µ bag.

When used beneath a 90µ bag in a multi-bag system, it captures material that passes through the 90µ screen but is retained by the 73µ mesh.

The 73µ fraction can also contain excellent resin.

Depending on the cultivar and trichome characteristics, it may even be one of the strongest-looking fractions from a particular wash.

Again, though:

73 micron doesn't automatically mean better or worse.

It's simply another size fraction.

73 vs. 90 Micron Bubble Hash: Quick Comparison

The biggest mistake is assuming the number printed on the bag tells you exactly how good the final hash will be.

It doesn't.

Is 73 or 90 Micron Better for Bubble Hash?

Neither micron size is universally better.

You may run one cultivar and discover:

90µ: excellent resin

73µ: excellent resin

Then process another cultivar and see completely different results.

That's because trichome morphology varies.

Several factors can influence the results:

• Genetics

• Plant maturity

• Starting material quality

• Fresh frozen vs. dried material

• Trichome head size

• Wash technique

• Water temperature

• Agitation

• Number of washes

  
  

Instead of asking:

"Which micron is always best?"

A better question is:

"Which micron produced the best fraction from this batch?"

Why Genetics Matter

Different cultivars can produce different trichome structures.

Some may have relatively large glandular heads.

Others may produce smaller heads.

This affects where desirable resin is collected in your filtration stack.

That's also why copying another extractor's favorite micron isn't always useful.

If someone tells you:

That may describe their experience with certain material, but it isn't a universal rule.

Your own extraction may tell a different story.

Why Use Both 73 and 90 Micron Bags?

Using both gives you more control over separation.

Imagine removing the 73µ bag.

Material that would normally be separated there may continue into the next smaller micron fraction.

Or imagine removing the 90µ bag.

Material normally separated at 90µ may become mixed with the fraction below it.

A complete filtration set allows you to see where your resin is actually landing.

That's particularly useful when:

• Testing a new cultivar

• Comparing washes

• Evaluating quality

• Troubleshooting yield

• Trying to improve consistency

Once you understand how your material behaves, you can make better decisions about your extraction process.

Where Do 73 and 90 Micron Bags Go in the Stack?

In a full BubbleBagDude 8-bag system, the micron sizes include:

220µ → 190µ → 160µ → 120µ → 90µ → 73µ → 45µ → 25µ

Each screen progressively separates smaller material.

The larger micron screens help remove larger particles while the finer screens collect increasingly smaller fractions.

BubbleBagDude 8-Bag Micron Sizes

Remember that the quality inside each bag still depends heavily on the starting material.

Does 90 Micron Mean Full Melt?

No.

A common misconception is that a certain micron number automatically equals full-melt bubble hash.

It doesn't.

Micron size tells you about particle-size separation, not final quality.

A 90µ fraction could be exceptional.

It could also contain contaminants or immature material.

The same is true for 73µ.

Melt quality depends on what's actually collected in that particular fraction.

Related Guide: How to Read Bubble Hash Grades: Full Melt to Cooking Grade

Can 73 Micron Be Full Melt?

Potentially, yes.

A clean 73µ fraction from suitable starting material can contain highly desirable resin.

But again, the bag itself doesn't create quality.

Think of your bubble bags as sorting tools.

They separate material by size so that you can evaluate the fractions individually.

The quality originates with the starting material and how well the extraction is performed.

Why You Should Keep 73µ and 90µ Separate

When you're learning a cultivar, don't immediately combine your 73 and 90 micron collections.

Keep them separate.

This lets you compare:

• Color

• Aroma

• Texture

• Visible contamination

• Yield

• Dry characteristics

• Melt behavior

You might discover that one fraction consistently performs better.

You may also discover that they're similar enough that combining them makes sense for your particular goal.

But evaluate first.

Combine later.

Compare Microns Across Multiple Washes

There's another important variable:

Wash number.

Your 90µ fraction from Wash #1 may look different from your 90µ fraction from Wash #3.

Likewise:

73µ Wash #1

may not look identical to:

73µ Wash #4

That's because later washes can expose the material to additional agitation and potentially release more plant particles.

For better troubleshooting, label your collections.

For example:

90µ - Wash 1

73µ - Wash 1

90µ - Wash 2

73µ - Wash 2

Now you can see exactly where changes happen.

Related Guide: How Many Times Should You Wash Bubble Hash?

Does a Smaller Micron Number Mean Better Hash?

No.

This is another common beginner misunderstanding.

You might assume:

25µ must be better than 73µ because it's finer.

That's not what the number means.

The micron number describes the mesh opening size.

It does not represent a quality score.

Smaller isn't automatically better.

Larger isn't automatically better.

Every bag is separating a different size range.

What About 45, 120, and Other Micron Sizes?

Don't ignore the rest of your bags because you've heard that 73µ or 90µ is the "good stuff."

Depending on your material, useful resin can appear across several fractions.

120 Micron

Can capture larger resin heads and other material that doesn't pass into the 90µ fraction.

45 Micron

Collects smaller material that passes through 73µ.

25 Micron

Acts as a very fine collection screen in the full 8-bag system.

Your results may vary substantially from cultivar to cultivar.

That's exactly why multiple micron sizes are useful.

73 vs. 90 Micron Yield

Which bag produces more?

Again, there isn't a universal answer.

Yield distribution depends on the size and abundance of the trichomes in your starting material.

For example, one hypothetical batch might produce:

Another cultivar could produce an entirely different distribution.

Don't chase a specific number because you saw someone else's extraction online.

Track your own results.

Keep a Micron Yield Log

If you're processing the same cultivars repeatedly, recording your results can be extremely useful.

Try tracking:

Over time, you'll start seeing patterns.

You may learn that a particular cultivar consistently concentrates desirable resin around 90µ.

Another might perform exceptionally well around 73µ.

That's useful information you can apply to future batches.

Don't Judge Bubble Hash Only by Color

A beautiful blonde 90µ pile may look impressive.

But appearance isn't everything.

Bubble hash color can vary because of:

• Genetics

• Trichome maturity

• Oxidation

• Starting material

• Storage

• Processing conditions

Likewise, darker hash isn't automatically poor quality.

However, obvious green plant contamination may indicate problems with the extraction process.

Related Guide: Why Is My Bubble Hash Green? 7 Causes & How to Prevent It

Keep Your Mesh Clean

Accurate separation depends on clean filtration screens.

If the mesh becomes clogged with resin or plant particles, drainage can slow down and make collection more difficult.

After extraction:

1. Remove collected material carefully.

2. Rinse the screens appropriately before residue dries onto the mesh.

3. Inspect the mesh for clogged areas.

4. Allow the bags to dry properly before storage.

5. Never store the bags wet.

Good maintenance helps your 73µ and 90µ screens continue performing as intended.

Related Guide: How to Clean Bubble Bags Without Damaging the Mesh

Do You Need an 8-Bag Set?

You don't necessarily need eight filtration stages for every situation.

However, a full set gives you much more information.

For beginners, that can be valuable because you can see exactly where different material is being captured.

With a complete BubbleBagDude 8-bag set, you can separate:

220, 190, 160, 120, 90, 73, 45, and 25 micron fractions.

Instead of guessing where your best resin is, you can inspect it.

As you gain experience, you can decide how much separation you want for different batches.

73 vs. 90 Micron: Which Should Beginners Use?

If you already have a complete bag set, use both.

There's little reason for a beginner to choose only one before learning how the material behaves.

Run the complete filtration stack.

Keep the 73µ and 90µ fractions separate.

Compare them.

Take notes.

Repeat.

You'll learn much more from your own results than from trying to memorize somebody else's favorite micron.

Final Thoughts: Is 73 or 90 Micron Bubble Hash Better?

Both 73 micron and 90 micron bubble bags can collect excellent resin.

Neither is automatically better.

The most important factors are:

• Starting material

• Genetics

• Trichome maturity

• Temperature

• Wash technique

• Contamination control

• Proper filtration

• Drying and storage

Use micron bags to separate and evaluate, not as automatic quality labels.

If you're working with a new cultivar, keep your 73µ and 90µ fractions separate and see what the material tells you.

That is one of the best ways to improve your bubble hash process over time.

Find the Right Bubble Bags for Your Setup

BubbleBagDude offers 5-gallon and 20-gallon bubble bag systems for different batch sizes and extraction setups.

A complete 8-bag set gives you multiple micron levels for separating and comparing different resin fractions.

Explore our Bubble Bags and Ice Water Extraction Equipment, or continue through our Ultimate Bubble Hash Resource Guide for more articles about micron sizes, washing, yield, troubleshooting, equipment, drying, and storage.

Frequently Asked Questions

Is 73 or 90 micron better for bubble hash?

Neither is universally better. Both can collect high-quality resin, and the better-performing fraction depends on the genetics, trichome size, maturity, starting material, and extraction process.

What does a 73 micron bubble bag collect?

A 73µ bag captures material that passes through larger screens but is retained by the approximately 73-micron mesh.

What does a 90 micron bubble bag collect?

A 90µ bag separates a larger size fraction than the 73µ bag. For some cultivars, this range can contain a significant amount of desirable mature resin heads.

Is 90 micron always full melt?

No. Micron size describes particle-size separation, not hash grade. A 90µ fraction isn't automatically full melt.

Can 73 micron bubble hash be full melt?

A 73µ fraction can potentially contain excellent melt-quality resin, depending on the starting material and extraction quality.

Should I combine 73 and 90 micron bubble hash?

Consider evaluating them separately first. If their quality and intended use are similar, you can decide afterward whether combining the fractions makes sense.

What micron bags are in an 8-bag set?

The BubbleBagDude 8-bag set includes 220µ, 190µ, 160µ, 120µ, 90µ, 73µ, 45µ, and 25µ filtration bags.