Cannabis Kief: Short Answer
Kief is the loose resin glands that fall off cannabis flower. The glands are called trichomes. They grow on the surface of the bud and hold most of the cannabinoids and terpenes in the plant. Grinding or shaking flower breaks the glands free. A screen catches them. The powder that lands in the bottom chamber is kief.
What Kief Is Made Of
Kief is not a strain. It is not a solvent extract. It is plant material that separated on its own. A sample holds trichome heads, small bits of plant matter, and waxes from the gland surface. Color runs from pale gold to light green. Green means more leaf matter came through the screen.
How Kief Collects in a Grinder
A three-chamber grinder does the work. Teeth shred the flower in the top chamber. The flower rests on a mesh screen in the middle. Glands and fine powder pass through the mesh and settle in the bottom chamber.
- Screen mesh: 75 to 125 microns in most grinders.
- Fine mesh: cleaner kief, slower yield.
- Coarse mesh: more plant matter, faster yield.
- A coin in the middle chamber pushes more kief through the screen.
Cannabinoid Content
Trichomes hold the cannabinoids, so kief tests higher than the flower it came from. Reported THC levels in kief run from about 20 percent to 60 percent by weight. Retail flower in the US sits near 15 to 25 percent THC. CBD hemp kief carries cannabidiol in place of THC. The exact number depends on the cultivar, the screen size, and how long the kief sat in the grinder.
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How to Use Kief
Bowl and joint topper
Add a pinch on top of ground flower. Kief burns hot and fast. A thin layer works better than a thick one. Too much kief can clog a pipe screen.
Pressed hash
Kief pressed with heat and pressure turns into hash. Hand pressure and a warm glass jar work. The trichome heads melt and bind into a solid block. Hash burns slower than loose kief.
Edibles need decarboxylation
Raw kief holds THCA and CBDA. Those acids do not produce effects. Heat converts them. Spread kief on a baking sheet and heat at 240 degrees F for 30 to 40 minutes. Then mix it into butter or oil. Fat carries the cannabinoids. Kief stirred into a cold drink will not work.
Storage
Kief is dry and loses terpenes fast. Keep it in a small airtight glass jar. Keep it out of light and away from heat. A two-year-old pile in a grinder will test lower than a fresh one.
Legal Status in the US
Federal law sets the line at 0.3 percent delta-9 THC on a dry weight basis. Kief from hemp flower below that line can be sold as a hemp product. Kief from marijuana is not legal under federal law. State rules differ. Check the state before buying.