Why Grades Matter
Not all bubble hash is equal. From a dark, crumbly 1-star cooking grade to a pale, sandy full-melt 6-star, the difference comes down to one thing: how much pure trichome resin you collected versus plant contamination.
The 1-6 star scale gives hash makers and consumers a common language. It's based primarily on the melt test — how cleanly the hash vaporizes when heated. The more complete the melt, the fewer contaminants, and the higher the star rating.
Understanding the grades matters before you start washing, because your input material and process largely determine which tier you'll land in before you press a single screen.
The Three Grade Tiers
1-2 Star — Cooking Grade / Food Grade
What it looks like: Dark green, brown, or black. Visible plant material mixed in. Crumbly or powdery. Strong plant smell alongside hash smell. May feel slightly greasy from chlorophyll contamination.
How it melts: It doesn't — not really. On a hot surface it burns and chars. Significant dark residue left behind. The plant material combusts rather than vaporizes.
Where it comes from: Typically from lower-quality trim, sugar leaves, or any material that's been over-agitated. The 25-45µ micron bags catch the finest plant particles alongside small trichome heads, which is why the smallest screens often produce cooking-grade output regardless of input material quality.
What to do with it: Decarboxylate at 110°C for 45-60 minutes and use in edibles, capsules, or infused butter. It works well for this — the contamination doesn't affect the high when eaten. Don't waste it trying to dab.
3-4 Star — Half Melt
What it looks like: Tan, light brown, or blonde. Less obvious plant material, though still present. Sandier texture than full melt. Smells noticeably more like resin than plant.
How it melts: Partially. It bubbles and partially liquefies, but leaves behind a layer of charred residue. If you're dabbing it, you'll need to swab your banger between hits. It's workable.
Where it comes from: Good-quality dried flower or well-handled trim, using 45-73µ or 90-120µ bags. Most Canadian home growers with 4 legal plants who wash dried trim will produce predominantly 3-4 star material — this is normal and nothing to be disappointed about.
What to do with it: Best consumed in a bowl with a mesh screen — it smokes well this way. Can be dabbed with care on a low-temp banger; just expect residue. Also excellent pressed into rosin, where the contaminants get separated out in the press. See pressing bubble hash to rosin.
5-6 Star — Full Melt / Ice Water Hash
What it looks like: Pale blonde, off-white, or light tan. Very fine, sandy consistency when dried properly. Minimal visible plant material. Smells intensely of terpenes — the hash equivalent of smelling fresh flower.
How it melts: Completely. Placed on a warm surface, it bubbles, liquefies, and disappears into clean oil. Little to no residue. 5-star leaves a thin, translucent film; 6-star is essentially nothing left behind.
Where it comes from: Fresh frozen material (same-day harvest, frozen immediately) combined with careful low-agitation technique and the 73-120µ sweet-spot bags. Fresh frozen preserves trichome integrity in ways dried material cannot. Also called IWEI (ice water extraction input) or live hash.
What to do with it: Dab it. Vaporize it. Full melt is the equivalent of dabbing live rosin without the press. Treat it like a premium concentrate — low-temp dabs around 170-190°C to preserve terpenes. Can also be pressed into top-tier rosin, though many prefer to consume it as-is.
The Melt Test — How to Actually Grade Your Hash
The melt test is the practical standard. Here's how to do it properly:
- Take a small sample — rice grain to pea size. Smaller is better; a large sample can fool you into thinking it melts less than it does.
- Use a dab tool — scrape a small amount onto the tip.
- Apply to a warm surface — a clean quartz banger at low heat, titanium nail, or even a piece of glass held over a lighter briefly. You want warm, not scorching.
- Watch the behaviour: Does it bubble? Does it liquefy? Does it leave a clean surface or dark char?
- Check residue — after the hash has finished, inspect the surface. Clean = higher grade. Dark, significant residue = lower grade.
Tip: Test multiple fractions separately. Your 73µ bag and your 90µ bag will likely produce different grades from the same wash. This is normal — grade each fraction on its own and use it accordingly.
One more thing: humidity affects the test. Hash that's only partially dried will behave differently than fully dried, freeze-dried, or properly cured hash. If your half melt seems to be performing worse than expected, complete the drying process and retest.
Micron Size vs. Grade: The Correlation
Your bubble bag micron sizes heavily influence which grades you collect. Here's how they typically map:
| Micron Range | Typical Grade | Why |
|---|---|---|
| 25-45µ | 1-2 star (cooking) | Catches fine plant particles alongside small trichome heads. High contamination almost regardless of input quality. |
| 45-73µ | 2-3 star | Better than the smallest bags, but still catches a fair amount of broken plant matter. Good for edibles or pressing. |
| 73-90µ | 3-5 star | The sweet spot for most strains. Full-melt potential with quality input material. This is where most growers see their best hash. |
| 90-120µ | 3-5 star | Catches larger trichome heads — great for high-yield strains with large heads. Grade depends heavily on input quality. |
| 120-160µ | 2-4 star | Catches larger debris including more plant material. Often a lower-quality fraction; useful for yield but not premium. |
The "sweet spot" range of 73-120µ is where most skilled extractors focus for quality hash. The finest bags (25-45µ) produce more volume but lower-quality material. Many experienced washers don't bother keeping the 25µ fraction as hash at all — it goes straight to edibles or gets pressed separately.
Micron sizing also varies by strain. A strain with large trichome heads (many OG Kush varieties, certain Afghans) may produce better hash from 90-120µ bags. Strains with small, dense heads often perform best at 73-90µ. If you're getting lower grades than expected, consider that your sweet-spot range might need adjustment for your specific genetics.
Input Material: The Biggest Variable
Technique and bag selection matter, but input material is the single biggest determinant of your final grade. The hash can only be as good as what goes in.
Trim
Sugar trim — the sugar leaves trimmed from buds — is the most common input for home growers. It's abundant (don't throw it out), produces decent hash, and doesn't require the coordination of a fresh frozen run. Realistically, dried trim will produce mostly 2-4 star material. It's worth running, especially in Canada where every gram of home-grown trim has real value. Just calibrate your expectations.
Dried Flower
Washing whole dried flower produces noticeably better hash than trim — more trichome density per gram of input, lower contamination from leaf matter. If you're washing buds, you'll typically see more 3-4 star output and occasional 5-star fractions from the 73-90µ bags. The tradeoff is you're using buds rather than trim.
Fresh Frozen
This is how 5-6 star hash is made. Harvest at peak ripeness, seal in a bag, freeze immediately. Don't let it dry. The cold preserves trichome integrity — the stalks don't degrade and the heads stay fully intact, which is what produces clean, full-melt hash.
For Canadian outdoor growers, a September or October harvest followed immediately by freezing is completely achievable. Running fresh frozen material through the right micron bags — particularly 73-90µ — is how home growers hit 5-star territory. It's not just a commercial producer thing.
Canadian context: Under the Cannabis Act, you can legally grow 4 plants per household. Most home growers harvest in late September to October outdoors, or run perpetual indoor cycles. Fresh freezing a portion of your outdoor harvest for a dedicated hash run is a low-cost, high-reward strategy that doesn't require any additional equipment beyond freezer space and your standard bubble bag setup.
Quick Reference: Grade Summary
| Grade | Stars | Melt Behaviour | Best Use | Typical Input |
|---|---|---|---|---|
| Cooking Grade | 1-2 ★ | Burns, chars, heavy residue | Decarb → edibles, capsules, butter | Trim, 25-45µ fractions |
| Half Melt | 3-4 ★ | Partial melt, some residue | Bowl (mesh screen), low-temp dab, rosin press | Dried flower, good trim, 73-120µ |
| Full Melt | 5-6 ★ | Clean melt, minimal/no residue | Dab, vaporize | Fresh frozen, 73-90µ sweet spot |
If you want to go deeper on the rating system, see our Bubble Hash Star Rating Guide for more on visual grading and what to look for at each level. If you're calculating expected yield from your material before you start, the Bubble Hash Yield Calculator is worth a look. And if you're planning to press your hash into rosin, the process changes a bit depending on grade — covered in our guide on pressing bubble hash to rosin in Canada.