Dry sift[draɪ sɪft]
Dry sift, commonly known as kief, is the cheapest concentrate to prepare and one of the most difficult. Considered a potent cannabis extract, dry sift is prepared by the build-up of trichome glands from cured cannabis leaves. To produce it, one is sifting cannabis through various-sized dry sift screens, depending on the size of the trichomes. Dry sift can be used alone, in combination with tobacco or cannabis buds for increased potency.
A succession of screens with varying micron grades is used in dry sifting. The cannabis matter is rubbed against a screen, enabling trichomes to fall through to the next screen for refinement. Many growers trim cannabis over a sieve during harvesting to capture fallen trichomes for dry sieve hash, rather than letting them fall to the ground and become waste.