Hashish is a cannabis concentrate product composed of compressed or purified preparations of stalked resin glands, called trichomes, from the plant. It is defined by the 1961 UN Single Convention on Narcotic Drugs (Schedule I and IV) as “the separated resin, whether crude or purified, obtained from the cannabis plant”. The resin contains ingredients such as tetrahydrocannabinol (THC) and other cannabinoids—but often in higher concentrations than the unsifted or unprocessed cannabis flower. Purities of confiscated hashish in Europe (2011) range between 4% and 15%. Between 2000 and 2005 the percentage of hashish in cannabis end product seizures was at 18%.
Hashish may be solid or resinous depending on both preparation and room temperature; pressed hash is usually solid, whereas water-purified hashish—often called “bubble melt hash”, or simply “bubble hash”—is often a paste-like substance with varying hardness and pliability; its color, most commonly light to dark brown, can vary from transparent to yellow, tan, black, or red. This all depends on the process and amount of leftover plant material (e.g. chlorophyll).
Hashish was the primary form of cannabis used in Europe in 2008. Herbal cannabis is more widely used in Northern America.
Hashish has been consumed for many centuries, though there is no clear evidence as to its first appearance. North India and Nepal have a long social tradition in the production of hash, known locally as charas.
The first attestation of the term “hash” is in a pamphlet published in Cairo in 1123 CE, accusing Nizari Muslims of being “hash-eaters”. The 13th-century Ibn Taymiyyah prohibited the use of hash; he mentioned that it was introduced to Levant with the Mongol invasion (throughout the 13th century). Smoking did not become common in the Old World until after the introduction of tobacco: until the 1500s hash in the Muslim world was consumed as an edible.