Dry (Solventless) extraction
Dry processing involves sifting ground cannabis material through either one screen or a series of metal mesh screens to separate the glandular trichome from the raw plant matter. The screens or meshes are stacked in order of size (for example 140 107 and 70 micrometers) – leaving at least an inch between each screen. The plant material is finely grounded and pushed over the upper screen to begin separating the trichome from the plant material. This process is then further repeated through each screen until finished. It yields hashish
that is typically amber in color containing roughly 90% glandular trichomes (see Figure 1). Anything that is not the glandular trichome is considered undesirable and is to be removed if the goal is purity.1
Watch a brief summary video on Cannabis concentrates and extracts
made in collaboration with Enlighten
or on the screens page
Figure 1: Hashish (image taken from Wikimedia Commons).
- Fairbairn, J. W.; Liebmann, J. A. (1973). The extraction and estimation of the cannabinoids in Cannabis sativa L. and its products. The Journal of pharmacy and pharmacology, 25(2), 150--5.