Bubble hash, named for the way it bubbles when smoked, refers to a specific type of hash made with ice water. To make bubble hash, cannabis flower is added to bags of ice water (called “bubble bags”) and agitated, which freezes and then breaks the resin glands from the flower. These broken resin glands, which contain essential compounds like THC and CBD, move through a series of screens while the plant material is left behind, forming bubble hash.
Bubble hash refers to a specific type of hash made with a process involving ice water. Like traditional hash, bubble hash is a solid concentration of cannabis resin glands, or trichomes. It can range in color from light blonde to dark brown. Bubble hash gets its name from its tendency to bubble when brought under a lighter’s flame.
“Full melt” is considered the highest quality of bubble hash. The ultra-refined full melt tends to largely bubble away when smoked or dabbed, leaving little material behind. You may also see hash rated on a scale of one to six, with six-star hash being the most refined and desirable. These highest quality hashes are made using extremely fine mesh sieves that prevent plant material from passing through—only the small trichome heads.
Kief describes the dried resin glands that coat the outside of a cannabis bud. It is the brown crystalline powder that breaks off from cannabis buds in a grinder. A simple way to differentiate kief from hash is that kief is the decompressed precursor of hash.
Both bubble hash and traditional hash are made from these resin glands, though they differ in preparation. Bubble hash is made using ice water, agitation, and a series of bags and screens while traditional hash is typically made through manual or mechanical separation and compression.