A seller who tells you “73 microns” isn’t telling you the quality of their resin. They’re telling you the size of a hole.
The number on a sieve refers to what passes through it, not what remains on top. That’s the whole difference—and it explains why this number has become the most common selling point in the CBD hash market, and the most meaningless one once taken out of context.
We’ve been sifting between 70 and 153 microns since 2020, from the Moroccan Rif to Switzerland. Here’s what these numbers really mean, how they affect taste and price, and why we never throw anything away.
Each tablet bears a serial number and a Swiss laboratory analysis. For each one, we specify the fraction from which it was derived—not a marketing figure, but the actual sieve size range.
A micron, or micrometer, is one-thousandth of a millimeter. Here are three points of comparison:
When sifting at 90 microns, we’re working on a scale where the eye can no longer keep up. That’s what makes marketing claims so easy here: no one can verify them by sight.
What interests us at this scale are the trichome heads. Their diameter isn’t fixed: it varies depending on the strain, maturity, and growing conditions.
The number on a sieve indicates the size of its openings.
What collects beneath a 120-micron sieve is therefore not “120.” It is everything smaller than 120 —including plant dust.
A properly described resin isn’t represented by one number, but by two. It has passed through one sieve and been retained by a finer one.
A 90-120 fraction passed through the 120-mesh screen and was retained by the 90-mesh screen: the larger pieces were removed at the top, and the dust at the bottom. What remains in the middle are the buds of the correct size.
When dealing with a seller: if only a single number is given, either they’re oversimplifying, or they’ve never sieved anything at all.
Cold makes the gland brittle and facilitates its separation. Too cold, and it breaks; too hot, and it sticks and gets crushed against the mesh.
This is the most underestimated factor. If it’s too moist, it won’t pass through anything. If it’s too dry, it crumbles into dust and contaminates all the fractions.
The first few minutes release the ripest glands— this is the prime portion. The longer you continue, the more plant material you extract. Knowing when to stop is better than knowing how to keep going.
These settings are detailed in our guide to sifting at home.
The principle applies to both dry sifting and bubble hash— only the agitation method changes. See the five extraction methods.
| Fraction | What’s in it | Appearance |
|---|---|---|
| Above 153 µ | Plant material, a few very large buds | Green, powdery |
| 120–153 µ | The largest buds, some debris | Dull blond, sandy |
| 90–120 µ | The main part of the harvest for many strains | Golden blond, shiny |
| 70–90 µ | Smaller buds, very clean sorting | Light blonde, fine base |
| Under 70 µ | Small buds, young glands, trichome stalks | Light-colored, dense powder |
Finer doesn’t necessarily mean better. Very fine sifting yields a visually flawless product that may disappoint on the palate. A broken bud has lost some of its terpenes before reaching the tray.
Coarser doesn’t mean bad. A 120–153 fraction from a plant with large glands outperforms a fine fraction derived from mediocre material. The quality of the source material always takes precedence over the fineness of the sorting.
We read everywhere that anything that falls below the commercial fraction is considered waste. That’s not true. There are three very real things in there:
The concentration is lower here, and the profile is different—more plant-like. That’s not the same as being worthless. To understand why these fragments matter, you have to look at how the plant builds these glands: not everything matures at the same rate on a single plant.
Here, nothing goes in the trash.
These fractions are extracted using solvents in a laboratory with appropriate venting equipment. This is not something to attempt at home: the solvents used are volatile and flammable.
The traditional method is infusion in a fat-based medium, such as Marrakech butter, and the CBD version follows the same principle. Cannabinoids and terpenes are fat-soluble: material that’s too low in content to be pressed can still be put to use once infused.
A micron is a mechanical measurement. It says nothing about:
It sounds technical, it’s reassuring, and it doesn’t commit you to anything. Other signs of a questionable product are covered in our article on fake resins.
The last two questions are the most revealing. They can’t be improvised.
No. These are two different fractions, not two levels of quality.
Resin whose trichomes have remained intact enough to melt completely without leaving any residue. An indicator of how thoroughly the resin has been sifted, regardless of the stated micron size.
They aren’t thrown away. Solvent extraction in an industrial setting, or infusion in a fatty substance at home. See what a decent resin really costs.
Not with the naked eye. But a 60× pocket microscope is enough to see if the trichomes are whole or broken —which often speaks louder than the number.
